Dissertationen zum Thema „Sustainable soil management“

Thesis (MPhil (Sustainable Development, Planning and Management))--University of Stellenbosch, 2010.
ENGLISH ABSTRACT: Sustainable agricultural management practices have a profound impact on soil carbon sequestration. The amount of carbon that can be stored in a given soil is influenced by climate, soil type, and the quality and quantity of organic inputs. Together, the interactive effect of these factors determines the Soil Organic Content (SOC). Sustainable agricultural management practices influencing Soil Organic Matter (SOM) include application of organic amendments, conservation tillage, and use of cover crops, crop rotations, crop residue management, and nutrient management. Increasing SOC enhances soil quality, reduces soil erosion, and increases agricultural productivity with considerable on-farm and off-farm benefits. To assess how management practices affect SOC, two case studies were conducted in Yavatmal district of Maharashtra in India and Lynedoch near Stellenbosch. The first case study examined the differences in SOC content on four farms each managed with 13 different sustainable agricultural techniques and one farm managed under conventional management practices. The second case study investigated the SOC differences between an organic and a conventional vegetable farm. The results of both studies show that farms that are managed under sustainable agricultural practices generally contain higher SOC content than farms that are managed under conventional agricultural practices.
AFRIKAANSE OPSOMMING: Om te bepaal hoe bestuurspraktyke Grondlikke Organise Koolstoff raak, is twee gevallestudies in die distrikte Yavatmal in Maharashtra, Indië, en Lynedoch buite Stellenbosch uitgevoer. Die eerste gevallestudie het die verskille in Grondlikke Organise Koolstoff -inhoud bekyk op vier plase waar 13 verskillende Volhoubare landboubestuurspraktyke het ‟n diepgaande impak op grondkoolstof-beslaglegging. Die hoeveelheid koolstof wat binne gegewe grond gestoor kan word, word deur klimaat, grondsoort en die gehalte en hoeveelheid organiese toevoer beïnvloed. Saam bepaal die interaktiewe effek van vermelde faktore die Grondlikke Organise Koolstoff -inhoud. Volhoubare landboubestuurspraktyke wat Grondlikke Organise Materiaal beïnvloed, sluit in die toediening van organiese verbeterings, bewaringsgrondbewerking, die gebruik van dekkingsoeste, oesrotasies, die hantering van oesresidu en voedingstofbestuur. Vermeerdering van Grondlikke Organise Koolstoff verhoog grondgehalte, verminder gronderosie en vermeerder landbouproduktiwiteit met aansienlike voordele op en verwyderd van die plaas. volhoubare landboutegnieke in die bestuurproses toegepas word, en een plaas wat volgens konvensionele bestuurspraktyke bedryf word. Met die tweede gevallestudie is ondersoek gedoen na die Grondlikke Organise Koolstoff -verskille tussen ‟n organiese en ‟n konvensionele groenteplaas. Die uitslae van albei studies dui daarop dat plase wat volgens volhoubare landboupraktyke bestuur word oor die algemeen hoër Grondlikke Organise Koolstoff-inhoud aantoon in vergelyking met plase wat volgens konvensionele landboupraktyke bedryf word.

It is well-known that there is a need for technical assessments to advise farmers, policy-makers and planners on indicators and methods for the assessment and monitoring of soil health and functions. These should focus on improving knowledge: on the roles and importance of diverse soil organisms in providing key goods and services; and on the positive and negative impacts of existing and new agricultural technologies and management practices.

Interest in evaluating soil quality in agricultural systems has been developed since improper soil and crop management decisions can result in resource degradation, and subsequently detrimental changes in soil functions. A wide range of soil attributes including physical, chemical and biological properties were measured in the paddy fields of the Veneto region, Italy over the 2012 growing season (i.e. in April after field preparation, field moist condition; June mid-tillering, the early period of waterlogging; August panicle formation, the late period of waterlogging; October after harvesting, drained soil condition). The paddy soils were under four different rotation systems (rice-rice-rice: R-R-R; soya-rice-rice: S-R-R; fallow-rice: F-R; pea-soya-rice: P-S-R) and three replications. Soil quality was evaluated using three different soil quality indices, namely: an additive index, a weighted additive index and systematic soil quality index, by integrating indicator scores (linear and non-linear) obtained either by expert opinion or principal component analysis. Another part of field and laboratory experiments were conducted at the International Rice Research Institute, research farm in Los Baños, Philippines, to evaluate the effect of three rotation systems (i.e. flooded rice – non-flooded rice, flooded rice – flooded rice, flooded rice – maize) and four fertilizer treatments (i.e. conventional N management, no rice residues; zero N, no rice residues; conventional N management, with rice residues; zero N, with rice residues) on some soil indicators, in order to have a comparison between two different environmental conditions. All soil quality indices proved to be suitable for assessing the effects of various cropping patterns on soil functions. However, almost all SQ indices obtained based on the non-linearly scored PCA-MDS proved to be significantly better than the other SQ indices calculated by other methods in evaluating soil quality. The results of stepwise regression highlighted that extractable phosphorous (mg kg-1), β-glucosidase, and water filled pore space were the main factors limiting 2011-2012 rice yield when using the EO-MDSs as the independent variable, whereas the 2010 yield was strongly explained by the scored PCA-MDSs including AWC, Zn, CEC and chitinase. In general, for most indexing method combinations, P-S-R rotation received statistically higher SQI values than the other rotation systems. However, the results of systematic soil quality index based on non-linear scoring method showed that S-R-R yielded the highest SQI, followed by F-R, R-R-R and P-S-R. We suggest, therefore, that rice cultivation with alternating leguminous crops (e.g. pea, soybean) could result in higher overall soil quality than monoculture crop or fallow-rice rotation. Our observations associated with the results of paddy fields in IRRI indicated that both the cropping patterns and fertilizer treatments had a significant impact on the most measured soil quality indicators. It seems that flooded rice-flooded rice cropping systems and conventional N fertilizer management have a higher soil health condition than other treatments. Our experiments demonstrate that the best management practice should be selected based on environmental conditions and particularly climate. However, further indicators should be measured to calculate the soil quality index value in order to understand the real soil health condition in the study area.

Implementation of Sustainable Management Practices at Two California Central Coast Vineyards and Their Effects on Soil Fertility Dawn Michelle Stimson “Sustainable agriculture” has gained increased popularity in recent years. This study was conducted to determine the effects of sustainable management practices on soil fertility at two California Central Coast vineyards. The effects of cover crops (Erosion Control Mix - blando brome [Bromus hordeaceus], hykon rose clover [Trifolium hirtum All.], and zorro annual fescue [Vulpia mourns]), green waste compost (Forest Blend), and reduced tillage on soil fertility were investigated in San Luis Obispo, California on a clay and sandy loam soil. Between the fall 2007 and spring 2008, which had a low precipitation amount (13.3 & 15.6 inches), there was a significant difference (P <0.001 to 0.007) between vineyards in terms of their mean soil nutrient and ratio concentrations. The range of soil values (soil pH, P, K, exchangeable Ca, Mg, and K, OM, Ca/Mg and C/N ratios) was either completely separate or different between Vineyard One and Two. There was almost no significant difference found between treatments and their effects on soil nutrients, exchangeable cations, and ratios. However, there were some noticeable effects on soil nutrients, exchangeable cations and ratios. Soil P and K concentrations increased in most areas (except cover crop/till where it decreased slightly). Soil P increases ranged from 14 to 143% while potassium increases ranged from 9 to 78%. Soil OM increased in all areas at both vineyards (5 to 55%). Ca/Mg ratios increased in some areas between 8 and 43%. C/N ratios increased in all areas between 5 and 85%. Soil type appears to affect soil nutrients, exchangeable cations, and ratios more than sustainable management practices. Keywords: Sustainable, vineyard, and soil nutrients.

Traditional agricultural practices often result in gaseous losses of nitrous oxide (N2O), ammonia (NH3), and carbon dioxide (CO2), representing a net loss of nutrients from agricultural soils, which negatively impacts crop yield and requires farmers to increase nutrient inputs. By adopting best management practices (BMPs; i.e., no-tillage, cover crops, sub-surface manure application, and proper manure application timing), there is great potential to reduce these losses. Because N2O and CO2 are also greenhouse gases (GHGs), climate change mitigation via BMP adoption and emissions reductions would be an important co-benefit. However, adopting a no-tillage and cover cropping system has had setbacks within the Northeast, primarily due to concerns regarding manure nitrogen (N) losses in no-tillage systems as well as uncertainty surrounding the benefits of cover crops. This thesis used two field-trials located in Alburgh, Vermont to assess differences in (i) GHG emissions from agricultural soils, (ii) nitrate and ammonium retention, (iii) corn yield and protein content, and (iv) N uptake and retention via cover crop scavenging under a combination of different BMPs. Chapter 1 evaluates the effects of different reduced-tillage practices and manure application methods (i.e., vertical-tillage, no-tillage, manure injection, and broadcast manure application) on reducing N2O and CO2 emissions, retaining inorganic N, and improving crop yields. Greenhouse gas measurements were collected every other week for the growing season of 2015-2017 via static chamber method using a photoacoustic gas analyzer. Results from this study showed that tillage regimes and manure application method did not interact to affect any of the three research objectives, although differences between individual BMPs were observed. Notably, vertical tillage enhanced CO2 emissions relative to no-tillage, demonstrating the role of soil disturbance and aeration on aerobic microbial C transformations. Manure injection was found to significantly enhance both N2O and CO2 emission relative to broadcast application, likely due to the formation of anerobic micro-zones created from liquid manure injection. However, plots that received manure injection retained greater concentrations of soil nitrate, a vital nutrient for quality crop production, thereby highlighting a major tradeoff between gaseous N losses and N retention with manure injection. Chapter 2 evaluates the effects of tillage practices and timing of manure application to increase N retention with the use of cover crops in order to mitigate GHG emissions, enhance soil nitrate and ammonium retention, and improve cropping system N uptake. Treatments at this field trial consisted of a combination of the presence or absence of cover crops, no-tillage or conventional-tillage, and spring or fall manure application. Greenhouse gas emissions were measured every other week via static chamber method using a gas chromatograph for the growing season of 2018. Results from this study showed that the presence of cover crops enhanced both N2O and CO2 emissions relative to fallow land, irrespective of tillage regime and manure application season, likely as a result of greater N and carbon substrates entering the soil upon cover crop decomposition. Due to enhanced N2O emissions with cover crops, cover crops did not retain significantly greater inorganic N in the system upon termination.

Much like other cities Stockholm has traditionally used a technical system for managing stormwater. With time this system has become overburdened and has led to large environmental concerns. To reach water quality goals set by the EU Stockholm needs to decrease pollution released to recipients by 70-80%.  Green infrastructure (GI) has increasingly been used as an alternative and addition to technical stormwater systems. Many studies have been conducted on different solutions and their stormwater management performance. The City of Stockholm have done research on numerous solutions to evaluate their performance in the context of Stockholm as well. However, implementation in the inner city is slow, thus this study explores why this is the case, and how Stockholm’s stormwater management goals can be reached. Stockholm predominately uses trees planted in plant beds using structural soil, and a combination of constructed wetlands and wet ponds for stormwater management. In new developments there is no real concern, as the GI can be included in planning at an early stage. Including these solutions in existing environments causes issues related to space, both above and below ground, and costs. Therefore, other solutions need to be found. This study explored green roofs, green walls and permeable pavements as possible options. Additionally, it found that finding new space that has previously not been used for GI could be an option. To mitigate financing issues new ways of promoting investment into GI from private property owners could be utilized, but that there also is a mismatch between supposed support for sustainable stormwater management on the political side and funds allocated. Finally, the study recommends that Stockholm takes the technical systems into account and explores what GI measures best work together with it to more effectively decrease pollution.

Evaluating soil health using bioindicator organisms has been suggested as a method of analyzing the long-term sustainability of agricultural management practices. The main objective of this study was to determine the effects of vineyard management strategies on soil food web structure and function, using nematodes as bioindicators by calculating established nematode ecological indices. Three field trials were conducted in a commercial Pinot Noir vineyard in San Luis Obispo, California; the effects of (i) fertilizer type (organic and inorganic), (ii) weed management (herbicide and tillage), and (iii) cover crops (high or low water requirements) on nematode community structure, soil nutrient content, and crop quality and yield were analyzed. Overall, although nematode ecological indices indicated that all plots had disturbed soil food webs, the indices proved to be less useful for measuring subtle differences in soil management over the short-term than anticipated. They showed few differences treatments. In general, the most pronounced differences were seen by sample location (under the vine or in the tractor row) and sample date, rather than treatment. None of the evaluated strategies affected crop quality, although fertilizer had a slight effect on yield. However, several indices were correlated with soil chemical parameters, including pH, nitrogen, carbon, and, to a lesser extent, EC. These results indicate that while nematode indices can be useful for comparing the state of the soil food web under long-term soil conditions, they may not be a robust measure of how agricultural management practices change soil health over a single growing season.

Sustainable land management (SLM) practices, as conservation agriculture (CA) and conventional tillage with cover crops (CC), aimed at balancing competitive agricultural production and environmental protection, have been encouraged throughout the EU through policy and subsidisation. Adoption of SLM practices that regulate biogeochemical cycles, however, requires further study, especially given the effects of local pedo-climatic variability and because middle and long-term effects are not fully understood and may differ from short-term outcomes. For these reasons, in this work, field experiments were conducted in three farms in the low-lying venetian plain, characterized by loamy soils, where CA and CC were compared to conventional intensive tillage system (CV) on trials established since 2010. The first objective of the thesis was to evaluate, by integrating experimental field results with model predictions, the potential ecosystem services provided by CA and CC practices on SOC dynamic, air quality and climate regulation, nutrition biomass and regulating of water conditions. In this experiment, CA and CC results contrasted according to the soil functions, the ecosystem service category and evaluation time span. The former was more effective in providing regulating services in the short term, and less consistent in the long term, at least for GHG mitigation. GHG control is only one of the numerous ecosystem services provided by conservation practices (e.g. reduction of erosion and P particulate loss). Many of these depend on the C content which are strongly affected by the C stratification processes. Cover crop adoption, on the contrary, showed promise in the long term, whereas short-term outcomes (two-year experiment) were negatively affected by poor cover crop growth. The second objective aimed to assess the SOC stock variation due to the adoption of CA and CC in comparison to CV within a large sample (i.e., 240) of 0-50-cm soil profiles, comparing two expansive soil sampling operations conducted in 2011 and 2017. The study showed that CA enhances SOC stratification rather than SOC accumulation, with high topsoil SOC that may have partly counteracted soil surface compaction. However, a comparison with previous SOC stock quantifications between CA and CV after three years of the experiment suggests that some SOC stock increase occurred, even at 50 cm, despite being not significant. The burial of fresh biomass-C with cover crops in arable systems (CC) enhanced SOC stock depletion most likely due to priming effects, suggesting that C input management is pivotal for its accumulation in agroecosystems with low soil fertility and low SOC protection capacity.

In the last years, intensive agriculture and high concentration of livestock activities have become two important environmental concerns, being partially responsible of nitrogen pollution and CO2 emissions caused by carbon loss from soil. That’s particularly true in Lombardy region, due to the presence of more than 27% of cattle and 51% of pigs of the national livestock and due to the extent of area devoted to cereal cropping (about 63% of the utilized agricultural area - UAA). It is also to be remarked that cereals in Lombardy are commonly grown in continuous cropping systems. In this context, the aim to encourage sustainable agriculture led European Union to introduce regulations (e.g. Nitrates Directive 91/676/EEC), to define mandatory standards, and measures (Common Agricultural Policy), to promote the implementation of best management practices. Consequently, assessing the potential effects of different policies, prior to their introduction, has become very important. Several methods (direct measurements, simulation models, simple and composite indicators) have been developed and applied by traditional agronomic research, however there is still a need of up-scaling experimental results from the farm to the landscape scale. Moreover, it has to be taken into account that the impact of these measures also depends on the interaction between type of action, pedo-climatic factors and farm characteristics. An effective tool for territorial management and planning is then particularly needed in Lombardy, since the territorial approaches, supported by robust methodologies (e.g., extensive databases, models and geographical information systems (GIS)), have become more and more central in European policies. The aim of this work is to assess and investigate the important outcomes of a more territorially based approach, analysing the most important environmental issues, related to agriculture in Lombardy: manure management, nitrogen leaching and carbon sequestration by soils. Three examples of tools and applications are presented: i) Decision Support System (DSS) ValorE, to analyse and to evaluate manure management and technological alternatives, available for the entire supply chain from animal feed to the distribution in the field; ii) application of the ARMOSA cropping system simulation model to assess the potential risk of nitrate leaching towards groundwater in 3 Nitrate Vulnerable Zones (NVZs); iii) application of ARMOSA to evaluate carbon sequestration capacity of regional soils, under current and alternative scenarios, focusing the attention on the impact of different spread levels of conservation agriculture. The territorial approach proposed in this thesis, was based on robust methodologies, extensive databases, stand-alone models (e.g. ARMOSA), more complex structures (ValorE DSS) and GIS techniques. All these components led this approach to be an effective solution for investigating and supporting the regional agricultural management, as well as for assessing the potential impact of the regional policies, always keeping in mind that agricultural sector plays a key role in the climate change mitigation and in the environmental protection from biodiversity loss and from N pollution.

The effect of management practices used by smallholder farmers to improve soil quality and increase maize yield was examined in an 80 ha. micro-watershed of central Malawi. Because of the complexity inherent in smallholder farming systems, this research proposed the combination of participatory methods with analytical techniques developed in field ecology, such as multivariate and spatial analysis. During a Participatory Rural Appraisal (PRA), farmers identified factors potentially influencing soil quality and maize yield. One hundred and seventy-six (176) plots were located in twenty-nine (29) fields and characterized for management practices and biophysical characteristics. Soil samples were collected at each plot and analysed for a suite of properties. The maize yield was measured for both 1996--97 and 1997--98 seasons. A formal survey was used to gather information on household characteristics. Results showed that management practices that were promoted by a previous extension project, such as alley cropping and the planting of grass on contour ridges, were strongly correlated and found mainly in fields located closer to house compounds. Farmers with a higher proportion of their land under wetland gardens tended to use less agroforestry. Food security was associated with households that were able to purchase inorganic fertilizers, had larger landholding size, and owned livestock and woodlots. The effect of management practices on maize yield and soil quality was partially confounded with characteristics of the plot, such as slope, degradation level, number of years under cultivation or pest damage. Higher maize yield was observed in plots that were better managed, as expressed by the combination of different management practices, lower pest incidence, fewer erosion signs and higher soil fertility. Some positive effects of alley cropping on soil quality were observed in plots that were cultivated for a longer period and located on flatter land. This study demo

Stormwater runoff is one of the main sources of pollution for urban waterways. Stormwater has traditionally been managed through concrete-based storm drainage systems, but the past twenty years have introduced an alternative in the form of green infrastructure. Green infrastructure for stormwater management involves the use of low impact development (LID), often vegetated facilities to mimic natural hydrologic systems that capture and allow infiltration of rainwater where it falls and from impervious surfaces upstream, before entering the drainage system. Portland, Oregon and Los Angeles, California have adopted green infrastructure into their stormwater management plans. For this project, bioswales, a form of vegetated LID facility, were tested in each city to determine their pollutant retention capabilities. Results from Portland show that bioswales filter out heavy metals effectively, and results from Los Angeles show that bioswales accumulate heavy metals in the soil over the course of the year (also due to filtering out metals from the stormwater). These results raise the question of whether accumulation can reach dangerous levels or saturate the soil with pollutants so that removal efficiency is diminished, indicating a need for further monitoring. However, the success of bioswales up to this point is encouraging and indicates that this method should continue to be employed.

Florida is the second leading horticulture state in the United States with a total annual industry sale of over $12 Billion. Due to its competitive nature, agricultural plant production represents an extremely intensive practice with large amounts of water and fertilizer usage. Agrochemical and water management are vital for efficient functioning of any agricultural enterprise, and the subsequent nutrient loading from such agricultural practices has been a concern for environmentalists. A thorough understanding of the agrochemical and the soil amendments used in these agricultural systems is of special interest as contamination of soils can cause surface and groundwater pollution leading to ecosystem toxicity. The presence of fragile ecosystems such as the Everglades, Biscayne Bay and Big Cypress near enterprises that use such agricultural systems makes the whole issue even more imminent. Although significant research has been conducted with soils and soil mix, there is no acceptable method for determining the hydraulic properties of mixtures that have been subjected to organic and inorganic soil amendments. Hydro-physical characterization of such mixtures can facilitate the understanding of water retention and permeation characteristics of the commonly used mix which can further allow modeling of soil water interactions. The objective of this study was to characterize some of the locally and commercially available plant growth mixtures for their hydro-physical properties and develop mathematical models to correlate these acquired basic properties to the hydraulic conductivity of the mixture. The objective was also to model the response patterns of soil amendments present in those mixtures to different water and fertilizer use scenarios using the characterized hydro-physical properties with the help of Everglades-Agro-Hydrology Model. The presence of organic amendments helps the mixtures retain more water while the inorganic amendments tend to adsorb more nutrients due to their high surface area. The results of these types of characterization can provide a scientific basis for understanding the non-point source water pollution from horticulture production systems and assist in the development of the best management practices for the operation of environmentally sustainable agricultural enterprise

This research is concerned with the dynamic relationship between agricultural advisers, knowledge and soil in England. On the basis that agricultural advisers have always played a central role in linking research and farming practice and implementing policy on the farm, the thesis explores the role of the adviser in facilitating a shift towards sustainable soil management (which encompasses a range of complex and knowledge intensive practices) and to the realisation of policy objectives in this domain. Specifically it aims to provide detailed empirical evidence of the role that agricultural advisers play in the acquisition, utilisation, generation and transfer of knowledge about soil best management practice and to elicit the factors that enable and constrain these knowledge processes. Conceptually, the research draws on approaches to knowledge and knowledge processes in agriculture from the allied disciplines of rural geography, rural sociology and extension science. An actor-oriented Agricultural Knowledge and Information System (AKIS) approach provides the basis for examining adviser interactions with both the research and farming communities. While the AKIS describes the factors that enable and constrain how advisers engage in knowledge processes in terms of connections across institutional interfaces between research, advice and farming, an actororiented approach, which understands knowledge processes as social processes operating across social interfaces, enables exploration of how individual advisers behaving as autonomous agents resolve these constraining and enabling factors. The- study, combining quantitative and qualitative methods, employs an extensive postal questionnaire survey of a 163 agricultural advisers from across England and three detailed case studies where sustainable soil management is a central theme, namely: the Landcare Project; the UK Soil Management Initiative; and the SUNDIAL Fertiliser Recommendation System. The data describe an advisory community with a range of involvement, concerns and competence in soil management. Patterns of acquisition and utilisation of knowledge about soil best management practice revealed by the questionnaire data suggest that advisers are actively seeking and using knowledge about soil management, although some are more constrained than others in accessing it. These patterns, however, only provide a partial understanding of the complex knowledge processes in which advisers engage as they operate at the boundaries between science and practice. As such, qualitative data from the case studies are used to reveal that, in bridging the different institutional cultures and life worlds of research and practice, advisers encounter different understandings and expectations of soil best management practices. Rather than simply acquiring, utilising and transferring knowledge, the data reveal that advisers negotiate, adapt, transform, generate and integrate knowledge about soil as they struggle to reconcile the principles of research-based soil best management practice with the practical and business constraints of the farm. In doing this advisers, and agronomists in particular, tend to closely align themselves with the interests of the farming community and as such are more likely to reject or question soil best management practice. In addition the apparent lack of advisers' competence and skills in certain knowledge intensive soil best management practices and their reliance on experiential knowledge further explains their reluctance to engage in soil best management practices derived from national research. Integration of knowledge through dialogue and understanding emerges as key to overcoming these tensions and providing the basis for facilitating sustainable soil management. Advisers are shown to have a central role in integrating knowledge from research and from farmers. The processes and relationships that enable this integration are identified. The thesis concludes with some policy relevant suggestions to improve the effectiveness of advisers' participation in the transition to sustainable soil management in England. These include: exploiting a diverse and flexible advisory community; improving advisers' skills and expertise; instilling in them confidence to provide credible and practical soil best management practice; and improving the quality of communication between the advisers, researchers and farmers. Future research directions are reviewed in the context of the proposed implementation of Soil Management Plans on all farms in England as a component of cross compliance within CAP reforms.

Thesis (PhD(Agric) (Agronomy))--University of Stellenbosch, 2009.
ENGLISH ABSTRACT: Continuous cropping without replenishing the nutrient component of soils will eventually lead to the depletion of soil nutrients. Small scale farmers in Zimbabwe often do not have the financial means to buy fertilizer and this problem is exacerbated by scarcity of commodities such as fertilizers. The use of herbaceous legumes such as mucuna (Mucuna pruriens) can assist to recapitalize soil fertility depletion and improve subsequent maize productivity in sandy loam soils in the small holder farming sector of Zimbabwe. In this study the effect of phosphorus (P) application to a mucuna crop, the effect of mucuna management options and the application of nitrogen (N) to the subsequent maize crop was investigated. The experiment was carried out during the 2007 to 2009 seasons at the Grasslands Research Station in Marondera in Zimbabwe. The soils are classified as humic ferrolsols and are predominantly of the kaolinitic order with sandy loams of low fertility and are slightly acid (pH CaCl = 5.2). A randomized complete block design was used for the effect of P on mucuna productivity and the effect of P and mucuna management options on the soil properties. The treatments were two P rates (P0 and P40 = 0 kg P ha-1 and 40 kg P ha-1 respectively) applied to a preceding mucuna crop, four mucuna management options [1) fallow (F) (no mucuna planted = control), 2) mucuna ploughed-in at flowering (MF), 3) all mucuna above ground biomass removed at maturity and only roots were ploughed-in (MAR) and 4) mucuna pods removed and the residues ploughed-in (MPR)]. A split-plot design was used to study the effect of P application to mucuna, mucuna management options and N rates on the growth and yield of the subsequent maize crop. The four N treatments [N0 = 0 kg N ha-1, N40 = 40 kg N ha-1, N80 = 80 kg N ha-1 and iv N120 = 120 kg N ha-1] were applied to a subsequent maize crop. Growth and development parameters such as biomass production, leaf area index, nutrient content of the foliage and grain yield were determined in the mucuna and maize crops. Soil parameters investigated included nutrient content, pH, bulk density and porosity. Phosphorus application in these particular soil conditions positively influenced mucuna biomass production and therefore enhanced the role of mucuna as a rotational crop by increased positive effects on the subsequent maize crop. The incorporation of above-ground biomass of mucuna had positive effects on all soil properties investigated. The MF and MPR management options increased the soil organic matter (OM) and reduced bulk density which leads to an improvement in porosity (f) of the soil. Mucuna incorporated at flowering (MF) and P40 treatment combination resulted in the highest mineral N, P, potassium (K), calcium (Ca) and magnesium (Mg) levels. A significant three-way interaction (P<0.05) between mucuna management options, nitrogen rates and time was observed in terms of biomass production and all nutrients in the leaves of the subsequent maize crop. The main findings were that the MF management option had the highest biomass and foliar nutrient accumulation through-out all the treatment combinations. In general the MF management option gave the highest maize yield across all the treatment combinations. Incorporation of mucuna biomass into the soil prior to planting a maize crop therefore improve soil physical and chemical qualities resulting in improved soil conditions for a subsequent maize crop which in turn lead to higher maize yields. Including a mucuna rotational crop have a similar effect on maize yield than application of 80 kg ha-1 of fertilizer N.
AFRIKAANSE OPSOMMING: Aanhoudende verbouing van gewasse op dieselfde grond sonder om voedingstowwe aan te vul lei uiteindelik tot die agteruitgang van die grond se vrugbaarheid. Kleinboere in Zimbabwe het meestal nie die finansiële vermoëns om bemestingstowwe te koop nie en die probleem word vererger deur die onbekombaarheid van kommoditeite soos bemestingstowwe. Die gebruik van kruidagtige peulplant gewasse soos mucuna (Mucuna pruriens) kan bydra om grondverarming teen te werk en om die produksie van ‗n daaropvolgende mielie aanplanting in sandleemgronde in ‗n kleinboerstelsel in Zimbabwe te verhoog. In hierdie studie is die invloed van fosfor (P) toediening aan ‗n mucuna aanplanting, die invloed van bestuursopsies van die mucuna en die toediening van stikstof (N) aan die daaropvolgende mielie aanplanting ondersoek. Die eksperiment is tydens die 2007 tot 2009 reënseisoen by die Grasslands Research Station in Marondera in Zimbabwe uitgevoer. Die grond word geklassifiseer as humiese ferrolsols en is hoofsaaklik sanderige leemgrond van die kaolinitiese orde met lae vrugbaarheid en is effens suur (pH CaCl = 5.2). ‘n Volledig ewekansige blokontwerp is gebruik om die invloed van P op die produktiwiteit van mucuna te bepaal asook die invloed van P toediening en mucuna bestuursopsies op grondeienskappe. Die behandelings was twee P vlakke (P0 = 0 kg P ha-1 en P40 = 40 kg P ha-1) wat aan ‗n voorafgaande mucuna aanplanting toegedien is, vier mucuna bestuursopsies [1) braak (F) (geen mucuna geplant = kontrole), 2) mucuna ingeploeg met blomtyd (MF), 3) alle bogrondse mucuna biomassa verwyder by rypwording en slegs wortels ingewerk (MAR) en 4) mucuna peule verwyde en die res van die bogrondse material ingeploeg (MPR)] en vier N behandelings [N0 = 0 kg N ha-1, N40 = 40 kg N ha-1, N80 = 80 kg N ha-1 en N120 = 120 kg N ha-1] toegedien aan ‗n daaropvolgende mielie aanplanting. Groei en ontwikkeling parameters soos biomassa produksie, blaaroppervlakindeks, nutriëntinhoud van die blare en graanopbrengs is in die mucuna en mielie aanplantings ondersoek. Grondeienskappe soos nutriëntinhoud, pH, bulkdigtheid en porositeit is gemeet. Fosfaat toediening aan hierdie spesifieke grondtipe het mucuna produksie positief beïnvloed en dus die rol van mucuna as rotasiegewas verbeter deur positiewe reaksies in die daaropvolgende mielie aanplanting. Die inwerk van bogrondse mucuna biomassa het al die fisiese grondeienskappe wat ondersoek is positief beïnvloed. Die MF en MPR bestuursopsies het organiese materiaal inhoud van die grond verhoog en bulkdigtheid verlaag wat lei tot verbeterde grondporeusheid (f). Mucuna wat tydens blomvorming ingewerk is (MF) lei tot die hoogste minerale N, P, kalium (K), kalsium (Ca) en magnesium (Mg) vlakke. ‗n Betekenisvolle drie-rigting interaksie (P < 0.05) tussen mucuna bestuursopsies, N vlakke en tyd is waargeneem in terme van biomassa produksie en in terme van al die nutriëntvlakke in die mielieblare wat ondersoek is. Die hoofbevindinge was dat die MF bestuursopsie die hoogste biomassa produksie en blaarnutriënt akkumulasie oor alle behandelingskombinasies tot gevolg gehad het. In die algemeen het die MF bestuursopsie die hoogste mielie-opbrengs oor alle behandelingskombinasies tot gevolg gehad. Die inwerk van mucuna materiaal in die grond voordat mielies geplant word verbeter dus fisiese en chemiese toestande in die grond wat grondtoestande verbeter vir die daaropvolgende miegewas en uiteindelik lei tot hoër mielie-oeste. Die insluiting van mucuna as ‘n rotasiegewas het diesefde effek op mielie-opbrengs as die toediening van 80 kg ha-1 N bemesting.

Drought and heat stress are the most important climate change factors decrease water and nutrient uptake and therefore negatively affect wheat growth. Surface soil drying decreased both water and NH4+ uptake from the top soil. However, increased water availability with bottom watering increased water uptake from the bottom soil layer, but not NH4+ uptake from the bottom soil layer. With surface soil drying, plants grew more and longer roots in the bottom soil layer, shifting water uptake from the top to the bottom soil, while N uptake was reduced in the top soil because of a decrease in root biomass. Drought stress and heat stress decreased the yield of all wheat genotypes, in particular 249, while combined drought and heat stresses had the most pronounced negative effect on plant biomass and grain yield. Decreasing soil water availability decreased plant-derived C to soil organic carbon (SOC) and microbial biomass through rhizodeposition. Wheat genotypes with smaller root/shoot ratios and thinner roots were more efficiently assimilating C to the grain, while genotypes with higher root/shoot ratios and thicker roots allocated more C belowground through rhizodeposition at the expense of producing more yield. Increasing water availability from 15 % to 25% and reducing air temperature 30 to 25 °C increased N uptake by plants thereby reducing overall N loss, and increased transfer of N from vegetative parts to grain. While crop rotation did not affect soil available N and P, AMF colonization in wheat was on average 60% higher after chickpea than after the canola rotation. Wheat yield after chickpea increased for genotype IAW2013, and was positively related to AMF colonization for both genotypes. N and P fertilization reduced AMF colonization and yield, but increased shoot biomass and leaf tissue N and P concentrations. Leaf δ13C decreased with increased yield, suggesting that higher yielding and AMF colonized plants were less water stressed.

Thesis (PhD)--Stellenbosch University, 2004.
ENGLISH ABSTRACT: This project aimed at enhancing the net benefit in production systems. It took a holistic approach to evaluate the potential interactions of herbaceous legumes in relation to weed dynamics, soil fertility and livestock management in the crop-livestock system in Nigeria. The project was carried out between 2000 and 2002 in two localities. These were the National Animal Production Research Institute (NAPRI) at Zaria in the northern Guinea savannah and the International Institute of Tropical Agriculture (IITA) at Ibadan in the derived savannah. The main experiment was carried out in the northern Guinea savannah, while the secondary experiments were simultaneously conducted in the derived savannah and the northern Guinea savannah. The experimental design for the three experiments reported in this thesis is a splitsplit plot, fitted into randomised complete block design (RCBD), with four replications. Main plot treatments were herbaceous legumes, namely Vigna unguiculata, Arachis hypogaea, Glycine max, Aeschynomene bistrix, Centrosema pascuorum, Stylosanthes guianensis and natural vegetation. Sub-plot treatments were management systems (1) M1, 'residues left in the field'; (2) M2, 'residues taken out of the field' and (3) M3, 'residues fed to livestock, manure/urine/refused feeds returned'. Sub-plot treatments were administered in a sequence following rotational fallows of herbaceous legumes and natural vegetation. However, plots in the secondary experiments were not subdivided before the cropping of maize in 2002, and for logistical reasons only two sub-plot treatments, M1and M2, are featured in this experiment. Herbaceous legumes were established at the start of the rainy season, approximately in June, in 2000, 2001 and 2002. All herbaceous legumes received single super phosphate (SSP) at 20kg ha" P20S at planting, while minimum hand weeding was done to maintain pure legume stands during the establishment phase. Forage biomass was higher in the derived savannah than in the northern Guinea savannah. Similarly, higher forage yields were observed after two consecutive years of legume fallow and natural vegetation, compared to the first year plots. Grain yield for Glycine max was consistently higher than for the other two grain legumes in 2001 and 2002. Chemical analysis of herbaceous legumes and natural vegetation showed that crude protein values ranged between 11.2% to 17.3% for legumes; that was significantly (p<0.05) higher than the 8.6% value found for natural vegetation. Moreover, all herbaceous legumes and natural vegetation, except Arachis hypogaea, had dry matter digestibility values of more than 30%. Maize grain and stover yields on herbaceous legumes fallowed plots were evaluated and compared with those for natural vegetation. Results in 2001, i.e. after a one-year fallow with legumes, indicated that the dry matter of maize grain and stover yields in the Stylosanthes guianensis plots were higher among the forage legumes. Arachis hypogaea gave the highest grain and stover yields among the grain legumes in the northern Guinea savannah. Results in 2002, i.e. after a two-year fallow, also showed that the productivity of maize planted on Arachis hypogaea and Glycine max fallowed plots were consistently higher across the three management systems tested in the Centrosema pascuorum, Glycine max, Aeschynomene histrix, Vigna unguiculata and least weight gain was recorded for the natural vegetation. Objective functions in linear optimisation, or linear combinations in algebra, used to link dynamic processes in livestock production (Iiveweight gain) with the dynamic processes in soils (soil nitrogen), weeds (weed biomass), herbaceous legumes (legume biomass) and crop production (maize grain and stover yields) under varying management systems took the form: Management system 1, Y, = f (XI, Xz, x4); Yr= 0 Management system 2, Y, = f (x" x2); Yz = 0 Management system 3, Y, = f (XI, Xz, xl); Yz= f (XI, Xz, X4. x5) Where (1) (2) (3) Y1 = Crop in kg; Y2 = Livestock weight gain in kg; X1= Weed in kg; X2 = Soil N g kg-1; X3 = Livestock compost in kg; N= Herbaceous legumes in kg; X5 = Maize stover in kg, for the three management systems considered in this experiment. Deductions from these equations showed that Aeschynomene histrix performed better under M1, i.e. when legumes residues were left on the field. Natural vegetation performed better than the herbaceous legumes under M2, i.e. when legumes residues were exported out of the field. However, the presence of manure in M3 enhanced soil fertility in the system and improved the overall productivity across all the legumes and natural vegetation. Overall rankings, conducted by pooling all components in the system, indicated that Glycine max performed best among the legumes, followed by Stylosanthes guianensis and Arachis hypogaea, which ranked second and viithird respectively. In relation to the specific legume groups, Stylosanthes guianensis performed better than the other two forage legumes, while Glycine max also performed better than the other two grain legumes tested. We can see from these on-station research results that there are indications of positive opportunities for improving overall productivity and resources. This can be done through integrating and complementing crop and livestock production, to provide a sustainable intensification of agriculture.
AFRIKAANSE OPSOMMING: Die studie is uitgevoer om die potensiële wisselwerking van kruidagtige peulplante met onkruiddinamika, grondvrugbaarheid en veebestuur te evalueer. Die hoofeksperiment in die "Northern Guinea Savannah" is vanaf 2000 tot 2002 uitgevoer by die "National Animal Production Research Institute" (NAPRI) in Zaria, Nigerië. Die twee sekondêre eksperimente is gelyktydig in Zaria en by die "International Institute of Tropical Agriculture" (liTA) naby Ibadan in die "Derived Savannah" uitgevoer. Die eksperimentele ontwerp was 'n dubbel gesplete perseelontwerp gepas in 'n volledig ewekansige blokontwerp met vier herhalings. Die hoofkomponente was die kruidagtige peulplante naamlik: Vigna unguiculata, Arachis hypogaea, Glycine max, Aeschynomene histrix, Centrosema pascuorum, Stylosanthes guianensis en natuurlike plantegroei. Die gekose peulplante is potensieel aangepas vir uiteenlopende omgewings en word dikwels na verwys as "'n mandjie van opsies". Subperseel behandelings was (1) peulplant gevestig en gelaat op die land - M1; (2) peulplant gevestig, geoes en weggeneem uit die land M2 en (3) peulplant gevestig, geoes, vir vee gevoer, mis/urine/vermorste voer terug na die land - M3. Die dubbel gesplete perseel behandelings is toegedien in 'n sekere volgorde nadat die peulplant rusoes/braak toegepas is. In die eerste jaar is die kruidagtige peulplante geplant op die hoofperseel van 25m by Sam. In die tweede jaar is die hoofperseel verdeel in twee persele waar onderskeidelik peulplante en mielies gevestig is terwyl daar in die derde jaar 'n verdere verdeling was wat gelei het tot verskillende gewasrotasiestelsels, nl. Peulplant-peulplant-mielies, peulplant-mielies-peulplant en peulplant-mielies-mielies. Parameters wat insluit planthoogte, -wydte en persentasie grondbedekking van die kruidagtige peulplante is tweeweekliks gemeet op vier 1M2 persele wat ewekansig oor elke hoofperseel versprei is in beide gebiede waar die studie uitgevoer is. Resultate het getoon dat die kruidagtige peulplante wat getoets is potensiële kandidate is vir insluitings in gewas/weiding rotasiesteiseis. Alhoewel voerproduksie hoër was in die "derived savannah" as in die "northern Guinea savannah", het die prestasie van die peulplante in die noordelike savannah gevarieer met die gewasproduksiestelsels. Hoër opbrengste is gerealiseer na twee opeenvolgende jare van oesrus met peulplante vergeleke met die eerste jaar waar daar geen residuele effek van die peulplante was nie, en die laaste jaar wat deur 'n mielie-oes voorafgegaan is. Biomassa opbrengste na twee jaar van aanhoudende verbouiing was die hoogste vir S. guianensis en die laagste vir A. hypogea. Ruproteien inhoud van die kruidagtige peulplante het gewissel van 170 g kg-1 DM in A. hypogea tot 62.4 g kg-1 DM in A histrix. Graanproduksie deur G. max was deurlopend hoër in 2001 en 2002 vergeleke met die twee ander graanproduserende peulplante nl. V. unguiculata en A. hypogea. Die voerproduksie in 2002 was heelwat hoër as die vorige jaar. Rotasie effekte op mieliegraan en oesreste na peulplante is vergelyk oor die dubbel gesplete persele (areas met verskillende oesruslengtes) om die ximplikasies van hulle residuele effek op grondvrugbaarheid verbetering en onkruid dinamika te bepaal. Mielie-opbrengs na een jaar van rusoes toon hoër waardes op persele wat onder kruidagtige peulplante was vergeleke met natuurlike plantegroei. Net so was die opbrengs deurlopend hoër op persele waar daar graan peulplante was as waar daar voer peulplante was. Oor die algemeen was die waardes hoër vir G. max, gevolg deur A. hypogea, A. histrix, C. pascuorum, V. unguiculata, S. guianensis en die laagste vir natuurlike plantegroei. In terme van die bestuurstelsels, het persele wat kompos ontvang het (M3) beter as die ander twee bestuurstelsels presteer (2.6 Mg ha" mieliegraan). Produksie van mieliegraan en oesreste na twee opeenvolgende jare van mielieverbouing was die hoogste na G. max (7.2 Mg ha" mieliegraan), gevolg deur die A. histrix perseel en die laagste op S. guianensis persele. Algemene waarnemings oor die twee subpersele wat met mielies beplant was in 2002 het getoon dat mielies beter presteer het op persele wat twee opeenvolgende jare met peulplante beplant was. Onkruidsamestelling en verspreiding is in beide die peulplante en natuurlike plantegroei gemeet. Grond vir saadbankontledings is op diagonale transekte in 0.5m by 0.5m kwadrate gemonster. Grondmonsters is ge-analiseer vir pH, totale stikstof, organiese koolstof, fosfor, kalsium en magnesium. Hierdie parameters is gebruik in 'n meervoudige regressie ontleding om hulle effek op onkruidspesievoorkoms te bepaal. Onkruidgetalle in lande na In rusoes het In deurlopende hoër vlak van besmetting getoon op die natuurlike plantegroei persele as op die peulplant persele. Die prestasie in terme van onkruidonderdrukking was in dalende volgorde: S. guianensis, C. pascuorum, V. ungucuilata, G. max, A. hypogaea en A. histrix. Die onkruidsamestelling het verskilonder die verskillende behandelings en dit het ook met tyd verander in dieselfde behandelings. In Bykomende eksperiment met die peulplante is uitgevoer om hulle effek op inname en groei van skape, asook die effek op kompos wat gemaak is van vermorste materiaal en uitskeidings van die skape, te bepaal. Droë materiaal verteerbaarheid was hoog vir S guianensis, G. max en A. histrix terwyl die laagste syfer verkry is by A. hypogea (177.6 g kg-1 DM). Ramme wat met kruidagtige peulplante gevoer is het beter presteer as die wat met natuurlike plantegroei gevoer is. Ramme wat met A. hypogaea gevoer is, het In gemiddelde daaglikse toename (GOT) getoon van 85.7 g daq", gevolg deur S. guianensis, C. pascuorum, G. max, A. histrix, V. unguiculata en laaste natuurlike plantegroei. Bykomende ontledings was gemik daarop om objektiewe funksies af te lei om dinamiese prosesse in vee (massatoename) met dinamiese prosesse in grond (grond N), onkruid (onkruidmassa), kruidagtige peulplante (peulplantmassa) en mielies (mieliegraan en oesreste massas) onder verskillende bestuurstelsels te verbind. In In poging om objektiewe funksies xiivan die verskillende komponente van die studie te bepaal, is die volgende lineêre funksies vir die drie bestuurstelsels oorweeg nl. Bestuurstelsel1. Yl = f (Xl, xz, x.); Yz= 0 Bestuurstelsel 2, Yl = f (Xl, Xz); Yz= 0 Bestuurstelsel3, Yl = f (Xl, X2, Xl); Yz= f (Xl. Xz. x.. les) Waar (1) (2) (3) Y1 = Oesopbrengs in kg; Y2 = Daaglikse massatoename in kg; X1 = Onkruidmassa in kg; X2 = Grond N in g kg-1 ; X3 = Kompos in kg; X4 = Kruidagtige peulplante in kg; X5 = Mieliereste in kg. Onder bestuurstelsel 1, het A. histrix beter as die ander gewasse presteer, terwyl natuurlike veld beter presteer het onder bestuurstelsel 2. Dit is 'n aanduiding dat bestuurstelsel 2 nie volhoubaar is nie. Die derde bestuurstelsel verteenwoordig volle integrasie van gewas en vee produksiestelsels. Die teenwoordigheid van mis in die stelsel het grondvrugbaarheid verbeter en algemene produktiwiteit verbeter. Hierdie resultate dui aan dat daar geleenthede is om algemene produktiwiteit te verbeter deur integrasie en komplementering van gewas- en veeproduksiestelsels om volhoubare intensifikasie van landbou te bereik.

This research investigates the influence of layout and design on the severity of trail degradation. Previous trail studies have been restricted by relatively small study areas which provide a limited range of environmental conditions and therefore produce findings with limited applicability; this research improves on this limitation by analyzing a representative sample of the Appalachian Trail with significant ecological diversity. Most trail science studies have also focused on a singular form of trail degradation, whereas this study investigates trail soil loss, widening and muddiness, providing a more cohesive analysis and revealing interrelationships between trail degradation processes. ANOVA testing of the mean values of three trail impact indicators for trail transects within several trail layout frameworks confirms the broad relevance of core trail design principles, specifically the sustainability advantages of trails with low grades and side-hill alignments. Findings also reveal the importance of landform grade in determining the susceptibility of trails to degradation and the influence of routing decisions; these relationships have received relatively little attention in the literature. The results also reveal several methodological considerations for trail alignment metrics and trail impact indicators.
Master of Science
Natural surfaced trails are an essential infrastructure component in parks and protected natural areas. They provide transportation routes through otherwise undeveloped areas and outdoor recreation opportunities for hikers, mountain bikers, and equestrians. Over time, recreational use and natural processes such as rainfall can lead to negative ecological impacts that damage trail treads in ways that impair their utility for visitors and require costly repairs. Environmental factors like unstable soils or extreme precipitation can make trails more susceptible to degradation. However, sustainable trail layouts and effective maintenance can reduce the rate and severity of degradation. This research investigates the influence of trail layout on three chief forms of trail degradation: trail soil loss, muddiness, and widening. Many trail science studies have occurred in small protected natural areas where the limited range of represented environmental conditions reduces the applicability of their findings in dissimilar settings. This study investigates a dataset from a large and ecologically diverse representative sample of the entire Appalachian Trail from Georgia to Maine which significantly broadens the relevance of its findings. Furthermore, many previous trail studies have focused on single forms of trail degradation whereas this study which investigates three, which provides a more cohesive analysis and reveals interrelationships between impacts. Findings confirm the broad pertinence of core sustainable trail design principles, specifically the benefits of low trail grades and side-hill alignments, and suggests that landform grade is an important factor which has received little attention in the literature. The study also revealed several methodological improvements and considerations which may be useful to trail scientists and practitioners.

This study aims to determine the safe and sustainable development and management of groundwater resources in Ergene River Basin located in northwestern Turkey. A numerical groundwater model was developed for the Sandy Complex aquifer, which is the most productive and the most widespread aquifer in the basin. The finite difference model with 5900 cells was used to represent the steady and unsteady flow in the aquifer. The model was calibrated in two steps: a steady state calibration by using the observed groundwater levels of January 1970, followed by a transient calibration by using the observed groundwater levels for the period of January 1970 and December 2000. The resulting model was used to develop groundwater pumping scenarios in order to predict the changes in the aquifer system under a set of different pumpage conditions for a planning period of 30 years between January 2001 and December 2030. A total of eight pumping scenarios were developed under transient flow conditions for the planning period and the results were evaluated to determine the safe and sustainable yields of the aquifer. The results, presented in the form of a trade-off curve, demonstrate that the continuation of the present pumping rates exceeds both the safe and the sustainable yields of the aquifer system.

La gestione del suolo nel sottofila del frutteto dipende in gran parte dall’uso di erbicidi chimici e dalle lavorazioni e questo concorre al declino della biodiversità e della qualità del suolo, e infine risulta dannosa per la sostenibilità della coltivazione. Tuttavia, il declino del suolo può essere contrastato praticando strategie alternative più sostenibili, singole o integrate. La gestione dovrebbe mantenere il suolo coperto nel filare degli alberi con specie viventi spontanee o selezionate per il loro ruolo vitale nei servizi dell'agroecosistema e nel miglioramento della biodiversità nel frutteto. Nel primo studio, due approcci meccanici integrati, la falciatura integrata (falciatrice e spazzola o disco) e la lavorazione integrata (sarchiatrice a lame e falciatura integrata), sono stati confrontati con il sistema gestito con erbicida standard in due frutteti commerciali di melo e pesco nelle Marche (Italia). Sono state misurate biodiversità del frutteto (copertura del suolo, numero di specie e produzione di biomassa), qualità del suolo (materia organica e contenuto di azoto), crescita degli alberi, resa e qualità dei frutti. Nel complesso, entrambe le pratiche integrate hanno dimostrato rispettivamente circa l'82%, il 91% e il 113% in più di diversità di specie, copertura del suolo e produzione di biomassa infestante rispetto al sistema gestito con erbicida. La falciatura integrata ha avuto effetti non significativi sulla sostanza organica del suolo e sulla disponibilità di azoto; tuttavia, è stato notato un miglioramento dell’equilibrio nel contenuto di azoto del suolo con riduzione del rischio della lisciviazione dei nitrati. Non è stato riscontrato alcun effetto negativo sulla crescita e sulla fisiologia degli alberi né sulla resa e sulla qualità dei frutti. I costi medi associati al controllo chimico delle infestanti sono stati rispettivamente del 66,5% e del 72% inferiori rispetto alla lavorazione integrata e alla falciatura integrata. Tuttavia, i sussidi forniti ai frutticoltori per incoraggiare pratiche di gestione sostenibile sono stati in grado di compensare tali costi aggiuntivi. Nello studio finale della tesi, sono state realizzate pacciamature viventi con due specie selezionate: Alchemilla vulgaris e Mentha piperita a confronto con la vegetaziona naturale sfalciata regolarmente (controllo) in un meleto biologico sperimentale a Skierniewice, in Polonia. Entrambi le pacciamature viventi selezionate hanno soppresso le erbe infestanti e migliorato la biodiversità del frutteto producendo il 42,5% in più di biomassa secca con il 29% in più di specie (numero) e il 33% in più di copertura del suolo, rispetto agli appezzamenti falciati. La clorofilla e il contenuto di nutrienti nelle foglie di melo sono risultati più elevati negli appezzamenti con pacciamatura viva selezionata rispetto al controllo. Inoltre, hanno prodotto una densità del peso secco delle radici di melo (RDWD) superiore del 30-46%, mentre altri tratti morfologici delle radici come la lunghezza della radice (RL), l'area della superficie della radice (RSA), il diametro della radice (RD) e il volume della radice (RV) non sono stati modificati in modo significativo. Questi risultati suggeriscono che le specie utilizzate per la pacciamatura vivente possono migliorare notevolmente la biodiversità del frutteto senza compromettere la produttività degli alberi e l'attività delle radici.
Orchard floor management in the tree row largely depends on chemical herbicides and soil tillage, and resulted in declining orchard biodiversity, soil quality, and proved to be detrimental to orchard sustainability. However, it can be restored by practicing more sustainable alternatives strategy either single or integrated. The practice should support covered soil with either spontaneous or selected living species in the tree row, as they can play a vital role in agroecosystem services and biodiversity improvement in the fruit orchard. In the first study, two integrated mechanical approaches; integrated mowing (mower and brush or disc) and integrated tillage (blade weeder and integrated mowing), were compared with the standard herbicide system in two commercial apple and peach orchards in Marche region (Italy). Orchard biodiversity (soil coverage, species number and biomass production), soil quality (organic matter and nitrogen content), tree growth, fruit yield and quality were measured. Overall, both integrated practices demonstrated approximately 82%, 91% and 113% more species diversity, soil coverage, and weed biomass production, respectively, than the herbicide systems. Integrated mowing had a non-significant effect on soil organic matter and N availability; however, an improvement was noticed while maintained a balance in soil N status by reducing nitrate leaching. No negative effect was found on tree growth, tree physiological constituents, fruit yield, and quality. The average costs associated with chemical weed control were 66.5% and 72% lower, respectively, compared to integrated tillage and integrated mowing. However, the government subsidies provided to the orchardists to encourage sustainable management practices were able to offset such additional costs. In the final study of the thesis, two selected living mulching species: Alchemilla vulgaris and Mentha piperita were compared with a mixture of natural vegetations with mowing (control) in an experimental organic apple orchard in Skierniewice, Poland. Both selected living mulches suppress weeds and enhance orchard biodiversity by producing 42.5% more dry biomass, 29% more species number, and 33% more soil coverage, compared to mowed plots. Apple leaf chlorophyll index and nutrient content were higher in selected living mulches plots than in control. In addition, they produced 30–46% higher apple root dry weight density (RDWD), while other root morphological traits such as root length (RL), root surface area (RSA), root diameter (RD), and root volume (RV) did not differ. These results suggest that the selected living mulching species can improve orchard biodiversity remarkably without impairing tree physiological constituents and root activity.

Due to the particular nature of accelerated soil erosion, its impact on food security is usually very intense. The impact starts first on the farmer, and then to his/ her environment. This is why soil erosion, when unchecked, is very devastating. Therefore this study was set to evaluate the perceived impact of soil erosion on food security in the Upper and Lower Areas of Didimana, Eastern Cape of South Africa, and the role farmers’ adoption behaviours play in the interaction. Three specific objectives were put forward by the study, vis-à-vis: (1) to establish farmers’ perceptions on the impact of soil erosion on food security of the study area; (2) to establish farmers’ innovation adoption behaviour with respect to soil erosion control in the study area; and (3) to establish farmers’ perceptions on the impact of extension activities with respect to soil erosion-control in the study area. The central argument of discussion is that soil erosion like every other agricultural problem, is the result of farmers’ non-adoption or inappropriate adoption of improved and recommended soil management technologies in the study area. The survey method of research was adopted for the study, where data were collected, using a well structured questionnaire, from a total of 60 farmers in the study area, through a simple random sampling process. Farmers’ perception suggested that the impact of soil erosion in their area is severe. This severity is demonstrated firstly in the form of climate change, as the time of rain in their area is gradually changing, and thus changing their time of cropping. Similarly the livelihoods of farmers are being negatively affected, as farmers’ crops, livestock, and even household feeding are being affected. More so, findings indicate that most farmers now plant fewer crops and there is an estimation of crop loss by most farmers of well between 21-60 percent of crops every year. Farmers’ perception further revealed that due to soil erosion, over 50 percent of farmers are unsustainable and a total of 71.7 percent of farmers’ population admitted that the amount of food available for their households is being severely affected. In virtually every sphere of human endeavours improved technologies have been developed to solve human problems, but the main reason problems like soil erosion is still very evident is the fact of farmers’ non-adoption or inappropriate adoption of specific recommended technologies. In the study area, the role of farmers’ adoption behaviour in the interaction of the impact of soil erosion on food security was very prominent. Findings indicate that despite the presence of certain recommended soil management technologies in the study area, majority of farmers do not use them neither extension advices. Moreover their satisfaction with those technologies was found to be low, which could be an explanation why they do not use them. For innovation to be adopted, rejected or utilized inappropriately, the effectiveness and performance of agricultural extension, as well as farmers’ perception play a great role. Thus in the study area, farmers’ perception on extension effectiveness indicates that extension hardly talk about soil erosion and its control during times of their visit. Similarly, farmers’ rating for extension services and advices was as well very low (23.4 percent). In fact, a comparison of farmers’ traditional methods of soil erosion control with extension recommendations (53.4 percent) indicated that farmers perceive their local methods of more importance than extension methods. In the same vein, majority of farmers in the area indicated that extension officers are inadequate in their jobs. Reasons offered range from issues of unreliability, lack of regular visits, communication problems, less attention for crop farming, and other reasons such as extension being unconcerned for subsistence farmers, as well as the fact that they focus more on cooperatives. In all, the findings of the descriptive statistics reveal that the impact of soil erosion on food security in the study area is very significant, and the results of the linear regression model of relationships in the study reveal that soil erosion relates positively with age of farmers, their product quality, and their sustainability. In a similar note, the innovation adoption behaviours of farmers was also found to be positively related to farm yield and food accessibility. Thus showing that innovation adoption behaviour of farmers in the interaction of soil erosion and food security in the study area is significant. Therefore, efforts should be geared toward improving factors that increases yield and accessibility of farmers to serve as boosters of farmers’ motivation towards the adoption of appropriate soil management technologies in their area.

Reconociendo la importancia de la urbe en el desarrollo sostenible global, esta tesis se enfoca en dos aspectos de la sostenibilidad urbana mediante una perspectiva metabólica. De acuerdo con las pautas metodológicas de la Análisis de Flujos de Materiales (Material Flow Accounting - MFA) presentadas por Eurostat en 2001, dos nuevas metodologías se desarrollan con el objetivo de evaluar la gestión de agua y de residuos Sólidos Urbanos (RSU). Ellas se aplican en los municipios litorales de la región metropolitana de Barcelona por un período de ocho años, no solamente examinando el sistema en su totalidad, sino también evaluando cada municipio por separado.
La primera metodología complementa MFA contabilizando todos los flujos artificiales de agua de un sistema, refiriendo a los flujos que consisten en el agua de tuberías y el agua drenada; se consideran también los flujos indirectos relacionados con las entradas y las salidas, correspondiendo a las pérdidas de agua. La segunda metodología describe eficientemente los flujos de RSU, no sólo dentro del sistema examinado sino entre sistemas vecinales también, contabilizando de las importaciones y exportaciones de RSU y los residuos secundarios generados en las plantas de tratamiento de RSU, siguiendo cada residuo sólido hasta su deposición final.
Consecutivamente, dos indicadores se proponen para la evaluación de la sostenibilidad urbana en relación con estos asuntos:
· Un indicador de sostenibilidad del uso del agua, basado en las demandas del sistema en términos del agua y del agua renovable que eso recibe en la forma de agua de lluvia.
· Un indicador adecuado para la revisión de las estrategias de la gestión de RSU, en línea con principios básicos de la gestión de residuos, que refleja la capacidad de un sistema para gestionar la cantidad de RSU que acepta y el grado del sostenibilidad de las prácticas del tratamiento dentro del sistema, valorando como la mejor opción el uso de residuos como materias primas.
El perfil energético del sistema estudiado se analiza también, empleando una metodología más simple para la descripción de sus flujos energéticos, por la importancia de estos flujos en un área urbana y con el objetivo de proporcionar una visión más completa sobre el metabolismo del caso de estudio.
Los resultados revelan un pobre funcionamiento metabólico para el sistema estudiado en términos de gestión de RSU, en ambos niveles espaciales, con bajos porcentajes de reciclaje y de reutilización. El sistema tiene un gran grado de dependencia de importaciones energéticas mientras la contribución de fuentes renovables es trivial. Con relación al agua, los resultados de su metabolismo demuestran la importancia de estos flujos para el sistema y la magnitud significativa de las pérdidas de agua. Los satisfactorios valores del indicador muestran que el sistema podría cubrir sus necesidades explotando el agua precipitada; sin embargo, la carencia de instalaciones relevantes en la mayoría de los municipios indica la necesidad de decisiones más atrevidas sobre la administración del agua en esta región que sufre de sequías severas.
Las herramientas propuestas en esta tesis se demuestran capaces de detectar las problemáticas y los cambios en relación con relevante infraestructura y políticas. Los dos indicadores finalmente, pueden servir como herramientas valiosas para el planeamiento o la remodelación de áreas urbanas, contribuyendo a/apoyando la toma de decisiones para la determinación del tamaño de la población, densidad y crecimiento urbano, conjuntamente con otros indicadores.
Recognising the important role of cities in global sustainable development, this thesis focuses on two urban sustainability aspects through a metabolic perspective. Based on the Material Flow Accounting (MFA) methodological guidelines presented by Eurostat in 2001, two new methodologies are developed with the aim to assess water and Municipal Solid Waste (MSW) management. These are applied on the coastal municipalities of the Barcelona metropolitan region for a period of eight years, not only examining the system as a whole but assessing in addition each municipality separately.
The first methodology complements MFA and accounts for all artificial water flows of a system, referring to the flows consisting of piped and drained water; input and output related indirect flows are also considered, corresponding to water losses. The second methodology describes efficiently the flows of MSW, not only within a given system but between neighbouring systems as well, accounting of the MSW imports and exports and the secondary waste generated in the MSW treatment plants, following each residue until its final sink.
Accordingly, two indicators are suggested for the measurement of urban sustainability regarding these issues:
· A water indicator that assesses the potential of a system for sustainable water management, based on the system's demands in terms of water and the renewable water it receives in the form of rainwater.
· An indicator suitable for the revision of MSW management strategies, in line with basic waste management principles, that reflects the capacity of a system to manage the amount of MSW it accepts and the grade of sustainability of the treatment practices followed within the system, valuing as the best option the use of residues as prime materials.
The energetic profile of the studied system is also analysed, employing a more simplified methodology for the description of its energetic flows, for the importance of these flows in an urban area and with the aim of providing a more complete view on the case study's metabolism.
The studied system has a poor metabolic performance in terms of MSW management and energy, on both spatial levels. The results reveal low recycling and reuse rates of MSW and extended transport of these. A great degree of dependence on energy imports is demonstrated while the contribution of renewable sources is trivial. Concerning water, results on the case study's metabolism demonstrate the importance of these flows for the system and the significant magnitude of water losses. Encouraging indicator values indicate that the system could cover its needs exploiting rainfall; yet, the lack of required facilities in the majority of municipalities indicates the need for more daring water management decisions in this region suffering from severe droughts.
The proposed tools are proved to be able to detect drawbacks and changes in relevant infrastructure and policies. The two indicators finally, can serve as valuable tools for the planning or redesigning of urban areas, supporting decision-making on determining population size, density and urban growth, in combination with other indicators.

Effective microorganisms (EM), a commercial concoction of microbes that includes yeasts, fungi, bacteria and actinomycetes, have been found to be effective in enhancing crop growth by a number of scholars. It is registered in South Africa, but it had not been thoroughly investigated. The present study investigated the effects of EM on growth, yield and quality of tomato (Lycopersicon esculentum Mill), butternut (Curcurbita moschata) and Swiss chard (Beta vulgaris), along with selected soil properties. In field-grown tomato it was observed that the application of EM caused a significant increase in the number of fruits at seven weeks after transplanting. However, plants treated with EM alone, or EM in combination with other amendments, subsequently produced lower yields owing to an outbreak of early and late blights which affected them the most severely. Combined applications of EM with organic amendments improved plant N content and increased soil N content above initial levels. The application of compost resulted in soil N and P concentrations higher than those of the control presumably due to nutrients being slowly released from the compost material. In a follow up greenhouse trial EM application had a negative effect on tomato leaf dry matter yield, number of leaves, number of trusses, fruit yield and number of fruits. The negative effects of EM were ascribed to N immobilization by the EM that could have resulted in reduced N availability to plants. The lower number of fruits associated with EM application resulted in improved average fruit weight of tomatoes grown in the greenhouse, possibly as a result of more assimilates being partitioned to the few fruits EM application also had a negative effect on field grown butternut as reflected by lower total yield, lower marketable yield and lower first grade yield. The results were attributed to immobilization of N induced by application of EM, and to the inability of EM to control pumpkin fly that attacked very young fruit, resulting in their failure to develop or resulting in the down grading of mature fruits. The application of EM alone had a positive but non significant effect on the yields of both the first and second harvests of Swiss chard. However, when applied with compost or goat manure, a non significant negative effect on yield was observed. When applied with inorganic fertilizer, EM had no effect on yield but tended to increase the uptake of nitrogen by Swiss chard. Though goat manure had a narrower C: N ratio than compost, it did not result in greater EM effectiveness as had been hoped. However, goat manure had a more positive effect on soil properties than compost. It increased the N, P, and K contents of the soil and resulted in a narrower C: N ratio of the soil compared to compost. Generally, the results of the four trials conducted with three different crops indicated that EM had inconsistent effects on crop performance.

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The use of forest resources in Northeast Brazil is still made in the irrational and predatory way in most areas of caatinga; because of this biome has suffered constant threats; often this is the simple lack of information on proper techniques of how to manage the forest. It has been observed in practice an increase in society's interest for the development of empirical management plans based mostly on personal needs of demanding inputs coming of forests, according to the law of barriers to predatory exploitation, it is perceived the need for studies that give support to the management of these resources; The objective of this study was to evaluate sustainable management techniques of the caatinga and its effects on recovery of the area and the maintenance of productive capacity, by assessing the physical and chemical soil properties. For that were selected in three areas of Settlement Tabuleiro Grande Design, municipality of Apodi / RN, located in geoenvironment the Apodi Plateau; The first corresponded to 3.2 acres where use was made of thinning techniques, lowering of the enrichment area and control the entry of animals, this being the area of sustainable forest management - AMS; the second with 5.6 hectares was submitted to management that is done in the traditional community, which practices the uncontrolled exploitation of the forest and the overgrazing, which is the area in conventional management - AMC; the third with 2.0 hectares is an integral part of the legal settlement of the reserve, which is the area of native forest - AMN. To preview the effects of management practices on the variation of soil properties after the expiry of five (5) years of intervention in the area of the soil samples were collected at 0-20 and 20-40 cm, and the use of electronic penetrometer for the determination mechanical resistance to penetration - RMP, the same points and the results submitted to analysis of variance and means compared by Tukey test at 1% and 5%. The results indicate management techniques of driving efficiency and AMS, lower values evidenced in bulk density (ds) shown in AMS (0.90 g cm-3) and AMN (1.03 g cm-3) compared AMC ( 1.16 g cm-3), which was directly related to the mechanical resistance to penetration (RMP), considering that higher values observed in the AMC (2337.29 kPa) compared to AMS (1397.30 kPa) and the AMN (1354.53 kPa) in the measured depth (0-40 cm); as the cause of overgrazing in the area, which was confirmed by the values of total porosity that showed higher in AMS, which shows the improvement of soil structure; moisture appeared higher in AMS compared to other areas due to the presence of litter in the area, which favors the maintenance of moisture and contributes to the increase of soil organic matter (SOM) and subsequent retention of more water; in addition to contributing to higher values of match (P), K+ and Mg2 + in AMS, followed by AMN; thereby evident degradation of AMC
O uso dos recursos florestais no Nordeste do Brasil ainda é feito de forma irracional e depredatória na maioria das áreas de caatinga; em função disso o bioma vem sofrendo constantes ameaças; muitas vezes isso ocorre pela simples falta de informações sobre técnicas adequadas de como se manejar a mata. Tem-se observado na prática um aumento do interesse da sociedade para a elaboração de planos de manejo empíricos baseados na maioria das vezes na necessidade pessoal dos que demandam os insumos advindos das florestas, em função das barreiras da lei a exploração predatória, percebe-se a necessidade de estudos que deem apoio à gestão desses recursos; o objetivo desse trabalho foi avaliar técnicas de manejo sustentável da caatinga e seus efeitos na recuperação da área e na manutenção da capacidade produtiva, através da avaliação dos atributos físicos e químicos do solo. Para isso foram selecionadas três áreas no Projeto de Assentamento Tabuleiro Grande, no município de Apodi/RN, localizadas no geoambiente Chapada do Apodi; a primeira com 3,2 hectares correspondeu, onde se fez uso das técnicas de raleamento, rebaixamento, enriquecimento da área e controle na entrada dos animais, sendo esta a área em manejo sustentável - AMS; a segunda com 5,6 hectares foi submetida ao manejo que tradicional se faz na comunidade, onde se pratica a exploração desordenada da mata e o superpastejo, sendo esta a área em manejo convencional - AMC; a terceira com 2,0 hectares é parte integrante da reserva legal do Assentam ento, sendo esta a área de mata nativa - AMN. Para visualizar os efeitos dos manejos na variação dos atributos do solo após ter decorrido 5 (cinco) anos de intervenção na área foram coletadas amostras do solo nas profundidades de 0-20 e 20-40 cm, além do uso de penetrômetro eletrônico para a determinação da resistência mecânica a penetração RMP, nos mesmos pontos e os resultados submetidos à análise de variância e as médias comparadas pelo teste de tukey a 1% e 5%. Os resultados indicam eficiência das técnicas de manejo e condução da AMS, evidenciados nos menores valores densidade do solo (ds) apresentado na AMS (0,90 g cm-3) e AMN (1,03 g cm-3) em comparação AMC (1,16 g cm-3), que apresentou relação direta com a resistência mecânica a penetração (RMP), tendo em vista que valores mais altos observados na AMC (2337,29 kPa) em comparação a AMS (1397,30 kPa) e a AMN (1354,53 kPa) na profundidade analisada (0-40 cm); como causa do superpastejo na área, o que foi confirmado pelos valores da porosidade total que se apresentaram superiores na AMS, o que evidencia a melhoria da estrutura do solo; a umidade se apresentou superior na AMS em comparação às demais áreas, devido à presença de serapilheira na área, que favorece a manutenção da umidade e contribui para o aumento da matéria orgânica do solo (MOS) e consequente retenção de mais água; além de ter contribuído para os valores mais elevados do fósforo (P), K+ e Mg2+na AMS, seguido da AMN; ficando assim evidente a degradação da AMC

Des pollutions des sols (péri)urbains et urbaines fortement peuplées en métaux et metalloïdes persistants (éco)toxiques sont couramment observées à l’échelle globale. Certains éléments (Se, Cu…) ont des rôles biologiques et par contre d’autres (Pb, Cd…) ont uniquement un impact (éco)toxique qui peut être influencé par leur spéciation et compartimentation qui modifient leurs transferts et biodisponibilité. Dans une optique de gestion des sols et d’alimentation durables, des questions scientifiques pluridisciplinaires sont à creuser concernant : (i) les mécanismes en jeu dans la biodisponibilité et l’impact sur les organismes vivants des éléments inorganiques en lien avec leur spéciation ; (ii) la co-gestion des risques environnement-santé induits par des installations industrielles classées : ICPE en France (ex. usine de recyclage de batteries) avec les riverains qui cultivent des potagers ou les employés. Dans ce contexte, ont été étudiés : (i) le transfert des métaux entre phase solide et solution du sol sous l’influence des vers de terre sur un site ICPE; (ii) le transfert et la bioaccessibilité du Se en conditions contrôlées pour 2 formes chimiques; (iii) le risque sanitaire pour les riverains d’un site ICPE qui jardinent, et les facteurs influant les plombémies des professionnels (étude statistique des données). Une review bibliographique de la qualité du manioc en lien avec les pratiques culturales et culinaires et les caractéristiques de l’environnement a finalement été réalisée pour compléter la démarche « Sciences et Société » de la thèse. L’analyse des différents isotopes du plomb dans les sols aux alentours de l’usine de recyclage a permis de conclure que 84 à 100% du plomb des sols de surface est d’origine anthropique. Un comportement d’évitement des zones les plus polluées en plomb a été observé pour l’espèce de vers de terre A. caliginosa. Le transfert racinaire, la translocation du sélénium vers le maïs et sa bioaccessibilité dans le grain sont plus élevés dans le cas du séléniate (facteur de translocation de 1.1, et bioaccessibilité humaine de 89,3%) par rapport au sélénite (0.13, et bioaccessibilité de 82,7%). L’étude de la qualité des cultures des jardins proches de l’usine (à Bazoches), en relation avec la qualité du sol (faible contamination, pH basique et teneur élevée en matières organiques qui réduisent les transferts) et de l’atmosphère a mis en évidence un transfert atmosphère-plante qui dépend du métal (le Cd est le plus biodisponible) et du végétal. Les concentrations en Pb et Cd suivent respectivement les séquences : [laitue>poireau>céleri>carotte] et [laitue>céleri>carotte>poireau]. Pour réduire l’exposition des populations, un lavage soigneux des productions avant la consommation est préconisé
Pollution of (peri)urban soils by (eco)toxic metal(loid)s is commonly observed on a global scale. Some elements (Se, Cu ...) have biological roles and other (Pb, Cd ...) only have an (eco)toxic impact influenced by their speciation and compartmentalization that can change their transfers and bioavailability. With the perspective of sustainable management of soil and food, multidisciplinary scientific questions are digging for: (i) the mechanisms involved in the bioavailability and impact on living organisms of inorganic elements related to speciation; (ii) the co-management of environmental-health risks from industrial regulated plants (ICPE in France, such as former battery recycling plant) with residents who grow vegetable gardens or employees. In this context, were studied: (1) the transfer of metals between solid phase and soil solution under the influence of earthworms on a ICPE site; (2) the transfer and bioavailability of Se in controlled conditions for two chemical forms; (3) the health risk for the residents with gardening activities near ICPE plant and factors influencing blood lead of professionals (statistical analysis of data). A literature review of the quality of cassava in connection with the cultivation and culinary practices and characteristics of the environment was finally performed to complete the "Science and Society" process of the thesis. From the analysis of different isotopes of lead in the soil around the recycling plant it was concluded that 84 to 100% of lead in surface soils has anthropogenic origin. Avoidance behavior in the most lead polluted areas was observed for A. caliginosa earthworm species. The selenium root transfer, translocation to corn and its bioavailability in the grain are higher in the case of selenate (translocation factor of 1.1, and human bioavailability of 89.3%) compared to selenite (0.13 and bioaccessibility 82.7%). The study of crops quality in the gardens near the ICPE plant (in Bazoches), in relation to atmosphere and soil quality (low Pb contamination, alkaline pH and high organic content that reduce pollutants transfers) highlighted an atmosphere-plant transfer which depends on the metal (Cd is the most bioavailable) and plant species. Pb and Cd concentrations follow respectively the sequences: [lettuce> Leek> celery> carrot] and [lettuce> celery> carrot> leek]. To reduce population exposure, thorough washing of productions before consumption is recommended

Rapportens syfte har varit att uppmärksamma återanvändningspotentialen hos jordmassor och hur resurseffektivitet kan optimeras i projekt Ostlänken samt stora infrastrukturprojekt i allmänhet. Det praktiska syftet med studien är att bidra till en mer hållbar masshantering i projekt Ostlänken. Denna rapport har skrivits i form av en fallstudie med två typfall där triangulering har implementerats i forsknings-metodiken för att kombinera kvalitativa med kvantitativa metoder. Kriterier för rapportens analys-metod är baserad på en samlad effektivitetsbedömning där analyserade kriterier är ekonomi, klimat och risk. Resultatet indikerar att jordmassor som transporteras med semitrailer utanför ett projektområde till en fiktiv deponi-plats är både mer kostsamt och emitterar mer CO2-ekv. jämfört med jordmassor som transporteras med dumper innanför ett projektområde för återanvändningsändamål. Analysen visar att en ökad maxlast i kombination med en kortare sträcka är det mest kostnadseffektiva alternativet. Studien belyser även vikten av att inkludera hela värdekedjan (beställare-konsult-entreprenad) och uppdatera branschens annars konservativa förhållningssätt gällande masshanteringsarbetet.
The purpose of the report is to pay attention to the reuse potential of soil masses in infrastructure projects, specifically the East Link Project and how resource efficiency can be optimized. The practical purpose of the study is to contribute to a more sustainable mass management in the East Link Project. This report has been written in the form of a case study with two types of cases where triangulation has been implemented in the research methodology to combine qualitative with quantitative methods. Criterions for the analytical method of the report are based on an overall efficiency assessment, where analyzed criterions are economy, climate and risk. The result indicates that excavated soil masses that are transported by semi-trailers outside the project area to a fictional landfill are costlier and emit more CO2 equivalents than soil masses that are transported by a dumper truck inside the project area for reuse purposes. The analysis indicates that an increased maximum load in combination with a shorter distance is the most cost-efficient option. The study also highlights the importance of including the entire value chain (client-consultant-contractor) as well as updating the industry's otherwise conservative approach to mass management.

L’ampleur de la transition agroécologique à effectuer transcrit la nécessité de tous les acteurs, du champ, à l’assiette, à s’associer et travailler ensemble. Le concept d’« Une seule santé » (« One Health »), se base sur le principe qu’il existe une connexion entre la santé des humains, des animaux, des plantes et de l’environnement. Ce travail de thèse visait à démontrer que cette théorie appliquée à la production de blé mais en incluant les pratiques culturales qui en sont au point de départ, n’est pas qu’un concept théorique, mais que ces liens entre les pratiques, la santé des sols, celle des plantes et les qualités nutritionnelle et sanitaire des produits récoltés, sont bien vérifiables sur la base de données de terrain.Pour ce faire, nous avons mis en place en 2021 un réseau d’étude à la ferme, composé de 86 parcelles agricoles cultivées en blé tendre d’hiver. La moitié de ces parcelles étaient cultivées selon les principes de l’Agriculture de Conservation des Sols (ACS), et l’autre moitié de manière « conventionnelle » (CONV). Les parcelles d’un agriculteur en ACS et d’un agriculteur en CONV ont été sélectionnées de manière à ce qu’elles puissent se comparer en binôme.En complément d’un diagnostic agroécologique (à l’aide de l’Indice de Régénération), nous avons procédé à une analyse fine et systémique des pratiques culturales appliquées à chaque parcelle étudiée, en prenant en compte les cinq campagnes précédant celle du blé étudié, ainsi que cette dernière. Un panel d’indicateurs de santé du sol, de santé de la plante, de qualité nutritionnelle et sanitaire de la récolte et de performances socio-économiques et environnementaux, a ensuite été testé sur chaque parcelle. Des investigations supplémentaires ont aussi été menées pour étudier des aspects spécifiques de composition des communautés microbiennes sur le continuum sol-plante-grain, en collaboration avec le Muséum d’Histoire Naturelle de Paris. Afin de clore la boucle de la « fourche à la fourchette », nos recherches sont allées jusqu’à la fabrication de pain, afin de potentiellement mettre en évidence les effets de ces pratiques agricoles contrastées sur le produit de consommation final.Notre étude a permis de mettre en évidence des niveaux de performance agroécologique plus ou moins élevés au sein même des groupes ACS et CONV, menant à des effets variables sur la santé des sols. De manière générale, nous démontrons pour ce réseau les effets positifs des systèmes ACS comparés aux systèmes CONV sur les principales fonctions qui contribuent à la santé des sols. Les effets sur la qualité du grain ont été plus délicats à mettre en évidence, du fait d’un important effet de l’année d’étude. Toutefois, nous avons pu observer les effets positifs de l’ACS sur les qualités nutritionnelles du grain (concentration plus élevée en P, K et ergothionéine). Enfin, nous montrons, dans nos conditions d’étude, que l'ACS se pratique sans perte de rendement tout en diminuant la consommation de gasoil et la charge de travail pour l'agriculteur. Nous montrons aussi qu’il est possible chez les ACS les plus performants, de limiter la dépendance aux engrais minéraux et aux pesticides de synthèse par rapport à leurs homologues CONV, ce qui est encourageant pour le développement de cette pratique d’un point de vue environnemental et de santé publique. Tous ces résultats suggèrent des effets positifs de la pratique de l’ACS sur l’environnement et sur la santé des consommateurs (humains ou animaux).Cette étude est le résultat d’un travail collaboratif à plusieurs échelles : avec les agriculteurs tout d’abord, qui ont pris part à la création du réseau d’étude, puis avec les multiples partenaires techniques, scientifiques et industriels, qui ont permis le déroulement de cette étude tout en horizontalité. Ce travail a finalement permis d’investiguer des aspects méthodologiques et analytiques de la santé des sols, des plantes et de la qualité nutritionnelle du blé en conditions réelles
The magnitude of the task reflects the need for all stakeholders, from farm to fork, to join forces and work together. The concept of "One Health", is based on the principle that there is a connection between the health of humans, animals, plants and the environment. This thesis aimed at demonstrating that this theory applied to wheat production but including the cultural practices that are at the starting point, is not just a theoretical concept. Indeed, these links between practices, soil health, plant health and the nutritional and health qualities of the harvested products, are verifiable on the basis of field data.To do this, we set up in 2021 an on-farm study network (OFE in the rest of the document: On-Farm Experiment), located mainly in the north-western quarter of France and composed of 86 agricultural plots cultivated with winter wheat. Half of these plots were cultivated according to the principles of Conservation Agriculture (CA), and the other half in a "conventional" manner (CONV). The plots of a farmer in CA and a farmer in CONV were selected so that they could be compared in pairs.After setting up this network of plots, we monitored each of them over a production campaign. In addition to an agroecological diagnosis (using the Regeneration Index), we carried out a detailed and systemic analysis of the cultivation practices applied to each plot studied, taking into account the five campaigns preceding that of the wheat studied, as well as the latter. A panel of indicators of soil health, plant health, nutritional and sanitary quality of the crop and socio-economic and environmental performances were then tested on each plot. Additional investigations were also conducted to study specific aspects of microbial community composition on the soil-plant-grain continuum, in collaboration with the Natural History Museum of Paris. In order to close the loop from “farm to fork”, our research went as far as bread making, in order to potentially highlight the effects of these contrasting agricultural practices on the final consumer product.Our study highlighted more or less high levels of agroecological performance within the CA and CONV groups, leading to variable effects on soil health. In general, we demonstrate for this network the positive effects of CA systems compared to CONV systems on the main functions that contribute to soil health, i.e. nutrient cycling, carbon transformation, structural stability of aggregates and biological regulation. The effects on grain quality were more difficult to highlight, due to a significant effect of the year of study. However, we were able to observe the positive effects of CA on the nutritional qualities of the grain (higher concentration of P, K and ergothioneine). Finally, we show, under our study conditions, that the practice of CA is carried out without loss of yield while reducing diesel consumption and the workload for the farmer. We also show that it is possible for the most efficient CA systems to limit dependence on mineral fertilizers and synthetic pesticides compared to their CONV counterparts, which is encouraging for the development of this practice from an environmental and public health point of view. All these results suggest positive effects of the practice of CA on the environment and on the health of consumers (humans or animals).This study is the result of collaborative work on several scales: first with farmers, who took part in the creation of the study network, then with the multiple technical, scientific and industrial partners, who allowed this study to be carried out horizontally. This work ultimately made it possible to investigate methodological and analytical aspects of soil health, plants and the nutritional quality of wheat in real conditions

La bioéconomie et l'économie circulaire se sont imposées récemment comme des composantes majeures des politiques de transition écologique, énergétique et sociale de l'Union Européenne. Soutenu par ces politiques publiques, le secteur de la méthanisation connait, depuis quelques années, un essor remarquable. La méthanisation permet en effet de produire à la fois du gaz issu de sources renouvelables, et du digestat, un co-produit aux propriétés amendantes et fertilisantes utiles à l'agriculture. Le « retour au sol » du digestat est d'ailleurs considéré comme un élément clé de la circularité de la filière méthanisation. Cependant, de nombreuses controverses demeurent sur les impacts environnementaux et sanitaires du retour au sol de digestats, et des conflits générés par les externalités négatives avérées ou supposées de la valorisation des digestats affectent le développement de la filière. Nous employons une méthode qualitative, centrée sur des analyses de cas, pour explorer ce sujet encore très peu étudié dans la littérature scientifique. Nous tentons de comprendre, tout d'abord, la nature de ces conflits puis, comment les mécanismes de gouvernance territoriale permettent d'anticiper ou de résoudre ces conflits. Nos résultats montrent que les conflits émergent autour de certaines dimensions du capital territorial : préservation du capital naturel, inadéquation du capital infrastructurel, et oppositions autour du capital culturel. Ces conflits cristallisent souvent des situations antérieures tendues, à l'échelle locale ou régionale. L'activation de la proximité territoriale, à différentes échelles, locale, régionale et sous-régionale, avec l'aide, parfois, d'un ou plusieurs intermédiaires publiques ou privés, permet aux acteurs des territoires de se coordonner pour, à la fois, échanger des informations et mieux mobiliser le capital territorial pour produire et acquérir de nouvelles connaissances en cas d'incertitudes sur les impacts des digestats, et pour élaborer des visions politiques communes autour du développement de la filière
The bioeconomy and the circular economy have recently gained a major place in the European Union policies on the ecological, energy and social transition. Supported by these public policies, the biogas sector has experienced a remarkable growth in recent years. Biogas production makes it possible to produce both gas from renewable resources, and digestate, a by-product which amending and fertilizing properties are useful for agriculture. The “return to the soil” of digestate is considered as a key element of the circularity of the biogas sector. However, numerous controversies remain over the environmental and health impacts of returning digestates to the soil, and conflicts related to the actual or supposed negative externalities of digestates negatively impact the development of the sector. We use a qualitative method, centred on the analysis of case studies, to explore this topic, about which the scientific literature remains very scarce. We try to understand, at first, the nature of these conflicts, and secondly, how territorial governance mechanisms can anticipate or solve these conflicts. Our results show that conflicts emerge around certain dimensions of the territorial capital: the preservation of the natural capital, the inadequacy of the infrastructural and equipment capital, and oppositions around the cultural capital. These conflicts often crystallize previous tense situations, at a local or regional scale. The activation of territorial proximity, at different spatial scales, local, regional and sub-regional, with the intervention, sometimes, of one or more public or private intermediaries, allows stakeholders to coordinate in order to: exchange information and better mobilize the territorial capital, produce and acquire new knowledge in the event of uncertainty about the impacts of digestates, and develop common political visions on the development of the sector

Les techniques alternatives représentent un enjeu majeur dans la gestion des eaux pluviales. C'est pourquoi les meilleures pratiques de gestion (MPG) sont largement appliquées dans la planification et la gestion urbaine. Ces techniques permettent de réduire les volumes d'eau et d'améliorer la qualité des eaux de ruissellement par traitement biologique.L'objectif principal de ce travail de thèse a été d'évaluer l'impact de l'activité lombricienne sur la perméabilité des sols limoneux argileux à travers le type et la densité des lombrics. L'expérimentation s'est basée sur deux méthodes d'analyse, l'écoulement gravitaire pour évaluer l'infiltration et le Radar haute fréquence (GPR) pour évaluer l'activité lombricienne.L'expérimentation a été réalisée selon deux cas de figures : en conditions contrôlées (air ambiant et humidité du sol) et en conditions réelles. Pour ce dernier cas, les boxes expérimentaux ont accueilli deux types de lombrics (Lumbricus terrestris et Aporrectodea caliginosa) dont l'activité a été suivie et surveillée par un système de monitoring : mesure du taux d'infiltration par écoulement gravitaire, mesure des paramètres physiques, mesure du signal radar suivie d'une analyse par la transformée de Fourier. Dans les conditions contrôlées l'impact de la densité des Lumbricus terrestris ( 25 individus/m^2, 50 individus/m^2, 100 individus/m^2 ) sur la perméabilité a également fait l'objet d'un traitement de signal radar suivi d'une analyse spectrale.Les résultats obtenus montrent pour les conditions contrôlées que l'impact des lombrics en termes d'infiltration (macropores et micropores) dépendent de la densité du Lumbricus terrestris testé. L'expérimentation dans les conditions réelles montre que l'impact des activités des deux types de lombrics est différent. Aporrectodea caliginosa donne de meilleurs résultats avec une augmentation de 200% de la perméabilité en 233 jours. Tandis que l'augmentation provoquée par Lumbricus terrestris n'est que de 77% pour la même durée. La combinaison de l'action des deux types de lombrics induit une augmentation intermédiaire de 107%.Le traitement de signal du radar via la fréquence à base de divers logiciels Reflexw et Matlab, montrent que plus la variation de la fréquence moyenne est rapide, plus l'activité des lombrics augmente dans le sol. Les résultats expérimentaux ont également montré une relation linéaire entre l'infiltration et les spectres de fréquence moyenne.Les résultats de nos recherches ont permis de quantifier la relation linéaire entre le type de lombric, la densité et l'infiltration du sol. La méthode non destructive (radar) représente un outil prometteur pour évaluer directement la perméabilité des sols à travers l'activité lombricienne
Stormwater management is always one of a challenge of urbanisation towards sustainable development. Therefore, best management practices (BMPs) are widely applied in urban planning and management. In addition, the evaluation and improvement of alternative stormwater management are still executed to reduce runoff volumes and quality on the ground by biological processing.The main objective of this study was to assess the impact of earthworm activity on the permeability of loamy clay soils through the type and density of earthworms. The experiment was based on two approaches, gravity flow to assess infiltration and high frequency radar (GPR) to assess earthworm activity.To accomplish the above objectives, two experimental models were set up: (i) one indoor experiment of boxes installed one type of earthworm (Lumbricus terrestris) with controlled conditions (air room and soil humidity); (ii) one outdoor with the average scale with natural conditions. Two type of earthworms (i.e. Lumbricus terrestris, Aporrectodea caliginosa) were experimented in boxes under parametric monitoring (measurement of the infiltration rate by gravity flow, measurement of the radar signal followed by a Fourier transform analysis).The first approach's findings indicate that the impacts of earthworms on soil infiltration (macropores and micropores) depend on the type of earthworms (i.e. Lumbricus terrestris, Aporrectodea caliginosa, and combined two) and density of earthworms (25 individuals/m^2 ( ind/m^2 ), 50 ind/m^2 , 100 ind/m^2 ). In addition, the outcomes gave the relationship of soil's natural conditions (temperature, humidity). The second approach's findings show that Aporrectodea caliginosa gives better results with a 200% increase in patency in 233 days. While the increase caused by Lumbricus terrestris is only 77% for the same duration. The combination of the action of the two types of earthworms induces an increase of 107%.The signal processing (frequency) of the radar based on various methods (Reflexw and Matlab) show that the faster the variation of the average frequency, the more the activity of earthworms increases in the soil. Experimental results also showed a linear relationship between infiltration and mid-frequency spectra. The results show that the faster variation of mean frequency is, the more earthworm activities increase in the subsurface. The experimental results also showed a linear relationship between infiltration and mean frequency spectra.The research results quantified the linear relation between earthworm type, density and soil infiltration. The non-destructive geophysical technology is also a promising tool for evaluating earthworm activity and soil permeability

This study was undertaken to research the principles and practices behind increased pasture productivity on Longslip Station, Omarama. A range of landscape - soil - climate - plant systems were identified, then analysed and the legume responses measured. By isolating cause and effect and appreciating the driving variables of each system, lessons learnt could be reliably and objectively transferred to the rest of the farm. Extrapolation to the balance of the property (15,150 ha) permitted immediate large-scale development and engendered confidence to lending institutions, Lands Department, catchment authorities and ourselves. Soil (land) cannot be well managed and conserved unless it is mapped reliably and its characteristics measured and interpreted by skilled observers (Cutler, 1977). Soil resource surveys, and their interpretation, are an essential ingredient of rational resource evaluation and planning. This thesis is a figurative and comparative survey and study of the soil catenary bodies, resident vegetation, legume establishment and pasture production characteristics of a 400 hectare catchment, in relation to, and as influenced by soil landscape unit, slope component, altitude, aspect and time. The inherent diversity in landform, soil properties and vegetation communities in a single catchment in the high country has not previously been fully studied or appreciated. This has lead to blanket recommendations for fertilizer, seed and management regimes both within and between properties and even regions. This study reports on the diversity of, yet predictable change in soil properties with slope position (upper, middle and lower) aspect and altitude in terms of both soil physical properties e.g. soil depth and water holding capacity and soil chemical properties such as pH, BS%, %P, %S, %N and %C. The composition of the resident vegetation and its differential response to oversowing and topdressing and subsequent change through time is reported and discussed. Finally an epilogue gives an insight into the problems and frustrations of farming practices in the high country from a motivation and personal perspective and political point of view that it is essential to come to terms with.

La gestion du foncier martiniquais est un sujet complexe, sensible et à forte densité politique. La superficie de la Martinique est de 1 100km2, soit l’une des plus petites régions françaises, avec la plus forte densité de population, soumise à de multirisques (cyclonique, sismique, volcanique, technologique, inondation, pollution de l’air, des sols et de l’eau, tsunami…).La triangulation urbanistique composée d’une multiplicité d’acteurs, de textes et de réglementations et d’un millefeuille institutionnel (6 niveaux d’administration : commune, intercommunalité, département, région, Etat, Europe) annihile toute responsabilité et obère un développement endogène de ce micro territoire.Un juste équilibre entre développement économique, social, culturel et environnemental doit être trouvé en conciliant les objectifs économiques et sociaux liés au développement insulaire.La remarquable biodiversité de la Martinique constitue un atout touristique indéniable, menacé par de fortes pressions anthropiques foncières.Cette recherche démontre la pertinence de la réglementation applicable au foncier à la Martinique et l’influence du développement durable sur cette réglementation. La thèse propose des solutions pérennes à mettre en œuvre pour pallier les incohérences juridiques révélées par l’étude
Management of land in Martinique is a complex, sensitive and highly political topic.The total area of the island is 1 100 km2 (square meters), e.g, one of the smallest French areas, with the highest concentration of population, submitted to multirisk desasters (cyclonic, seismic, volcanic, technological, flood, air, ground and water pollutions, tsunami…).The urban triangulation made up of a multiplicity of actors, texts and regulations, as well as a multi-level institutional cream cake (6 levels of administration: the city, the intercity, the Department, the Regional Council, the State and Europe), destroys all kind of responsibility and obstruct an endogenous development of this micro territory.A fair balance between economic, social, cultural and environmental development is necessary, by reconciling with the economic and social goals related to the insular development.The astonishing biodiversity of the island of Martinique represents an obvious tourist asset, threatened by strong land anthropic pressures.This research study highlights the relevance of the regulation applicable to the land in Martinique as well as the influence of sustainable development on this regulation. This thesis suggests perennial solutions to implement, in order to mitigate the legal inconsistencies pointed out by the study

En Chine, l'Etat reste le seul propriétaire de tous les terrains et par délégation, les collectivités territoriales gèrent elles aussi l'utilisation du foncier. Avant 1987, l'Allocation administrative (Allocation), souvent à titre gratuit, avait été la seule modalité d'offre foncière qui répondait aux demandes des utilisateurs publics. Dès que le droit d'utilisation du sol a pu être transféré légalement à partir de 1987, des réformes successives ont conduit au développement d'un "marché foncier". Le système d'offre foncière se décompose alors en deux modes principaux : le mode d'Allocation et le mode de cession. Les procédures, les acteurs et les utilisateurs agissant sur la dynamique foncière se sont de plus en plus complexifiés. Mais, le manque ou l'inefficacité des outils juridiques et des moyens pour assurer la gestion de la ressource foncière et sécuriser les transactions génèrent beaucoup de désordres et de dysfonctionnements dans le mouvement d'urbanisation accélérée en Chine. L'enjeu de ce travail est d'étudier l'articulation entre d'une part, l'offre foncière et d'autre part, la consommation excessive de terres agricoles, la rénovation totale des quartiers anciens de qualité patrimoniale, la rétention foncière et l'incohérence entre le marché du logement et les besoins fondamentaux résidentiels. Notre méthodologie a consisté en un large inventaire bibliographique pour assimiler les contextes fonciers chinois. Elle s'est aussi appuyée sur des entretiens avec différents acteurs intervenant dans l'urbanisme ainsi que sur des visites de terrains de trois études de cas : Beijing, Shanghai et Xi'an. L'objet de cette thèse est de tenter de comprendre, d'analyser, d'approfondir les fondements des régimes fonciers, et de saisir toute la diversité des situations réelles dans le but de favoriser l'urbanisation et le renouvellement urbain, en Chine, pour le futur. Au cours de cette réflexion, théorique et pratique, et en continuité avec le sujet de notre DEA, nous nous sommes demandé dans quelle mesure la pratique de l'urbanisme en France pouvait faire l'objet de transferts dans les villes chinoises.

Intensive agriculture and several anthropogenic factor led gradually to decrease soil organic matter and microbial biomass, thereby to a consequent loss of quality and fertility of soil. The sustainability of agricultural practices represents an aspect that could be not anymore negligible if environment protection and defense are the target. In the present thesis chemical and biochemical properties and humic substances characterization of agricultural soils, under greenhouse, amended with a mixture of compost from municipal solid waste enriched with poplar scraps in two different ratio and doses, were studied through a multidisciplinary approach. All parameters studied in a previous one year-experiment were followed for two years more, after yearly supply of organic amendment. This repeated treatment determined a strong improvement in most chemical and biochemical parameters. By increasing organic carbon, humic fraction, especially in the plot with higher C/N ratio and amendment dose supplied, increased to indicate the enhance of organic matter and the slow mineralization of organic mixture due to wood scraps that kept the organic matter input stable over time. The activity of the main enzymes involved in the biogeochemical cycles of nutrients markedly increased after amendments and then, after a visible decrease, remained stable over time without reaching the initial values, before the first amendment. A second study was carried out to assess the fertility of a soil under organic farming in comparison to another under conventional management, both cultivated with processing tomato (Solanum lycopersicum). Besides chemical and biological properties, investigated similarly to the previous study, soil microbiologic characterization and functional gene assess as Phytase from Bacillus sp. were performed. Organic farming favoured the enhance of soil fertility in term of organic carbon, total nitrogen, enzyme activities and in particular in microbial population. In fact soil biomass underwent an improvement of the presence and expression of functional gen Phy. The analyzed sustainable agricultural system improved the fertility of intensive arable soil and positively affected microbial biomass causing change and functional properties of microbial population.

This study reports results obtained and the approach taken in investigating the temporal sodium flux in a woodlot soil receiving secondary treated effluent at Branxton, NSW. Previous research has shown woodlot soils receiving secondary treated effluent undergo an increase in exchangeable sodium percentage (ESP) over time. Increased soil ESP influences micro-aggregate/soil pore stability and, particularly when subject to irrigation waters of specific low-electrolyte concentrations, results in decreased soil permeability and a subsequent need to reduce effluent application rates. Therefore, in irrigated woodlot soils it has been necessary to implement strategies to remove excess sodium from the root zone to maintain optimum permeability of the receiving soil, that is, maintaining the cation balance (as soil ESP) to promote optimum soil pore size. To maintain optimum permeability, an understanding is needed of temporal variations in the accumulation/leaching (flux) of sodium within a soil under secondary treated effluent irrigated conditions. The ability to define the sodium flux depends on the frequency of soil sampling and the ability to interpret the net loss/gain in soil sodium in relation to the applied hydraulic load over time. Past research has measured changes in soil ESP on an annual basis, or longer, making it impossible to interpret temporal sodium flux within a given year. The rate of change of soil ESP has ramifications for optimum permeability within an effluent irrigated woodlot. With respect to increasing/decreasing soil ESP, a major response of the clay particles within micro-aggregates is the deformation of conducting soil pores and reduced hydraulic conductivities. In addition, clay dispersion is governed by the soil ESP and electrolyte concentration of the infiltrating waters at the time, where dispersed clay particles may block conducting soil pores and further reduce hydraulic conductivity. Therefore, investigating the temporal sodium flux in conjunction with the temporal variation in electrolyte concentration of infiltrating waters will give greater insight into the response of effluent irrigated soils to sodium-rich waters over time. Three research aims were formed to investigate temporal sodium flux. These include: 1. To investigate trends in the dominant water balance components for a woodlot soil receiving secondary treated effluent (STE); 2. To examine temporal and spatial variation in both the water balance components and measured soil properties, particularly the sodium flux; and 3. To investigate the implications of the sodium flux on the loss of soil structure and drainage over time (dispersion events), particularly in relation to temporal changes in soil ESP and effluent SAR. Monitoring programs for water balance components and soil parameters covered the period January 2002 – October 2003. Every two months, soil samples were taken at designated sites and at different depths (10, 20, 40, 60, and 80 cm). These samples were analysed for exchangeable cations (Ca2+, Mg2+, Na+ and K+), from which the ESP values were derived. Also, this appears to be the first time that soil sampling at this frequency, which enables the temporal sodium flux to be determined, has been carried out. Column leaching experiments were also performed over the study period to illustrate the response of the woodlot soil, in terms of micro-aggregate stability, to hydraulic loads of varying SAR. Column leaching experiments also confirmed the rate of solute movement through the soil profile and the woodlot soil’s ability to bind/exchange sodium under different hydraulic loads and electrolyte concentrations. Soil extraction plate methods were used to determine wilting point and field capacity for these soils. The Sodium Adsorption Ratio (SAR), which is the solutional equivalent to soil ESP, was used to define the electrolyte concentration of the applied effluent and rainfall to the woodlot. The net loss/gain of exchangeable sodium at different depths and times was determined and compared with changes in water balance components and the measured volumetric soil water over time. The soil water surplus/deficit was recorded at a daily time-step and a cumulative approach was used to determine the long-term soil water surplus/deficit. In addition, variations in groundwater levels were monitored to observe if surplus irrigation events were reflected in temporal trends. As a result of determining the temporal variation in soil ESP, effluent and rainfall SAR, daily soil water deficit/surplus (short-term), cumulative soil water deficit/surplus (long-term) and volumetric soil moisture, temporal trends are presented. The sodium flux was then investigated by interpreting trends in the monitored data with respect to the dominant water balance components. All parameters were then used to model the potential dispersive behaviour of the receiving soil over time and depth, in relation to the volume and electrolyte concentration of the effluent and rainfall applied over time. The implications for soil structure and permeability depend on variations in soil ESP and effluent SAR. Results from this research show that soil ESP varied by as much as 24% over a four-month period and is shown to be a function of the sodium loading (from STE) and soil water surplus/deficit. On each sampling occasion, soil ESP generally increased with depth at all irrigated sites. Soil ESP at non-irrigated sites was much lower than irrigated sites, although the variability in soil ESP was much greater. Variations in SAR of the waters received by the woodlot soil (effluent and rainfall) over the study period ranged from 0.5 to 5.9. It is shown that the SAR range, coupled with variations in soil ESP, has ramifications for maintaining long-term soil structure. Soil structure at different sites within a woodlot will respond differently according to the soil ESP/effluent SAR relationship. The dispersive potential of soil at a given ESP receiving irrigation waters of known SAR was assessed in light of the relationship between soil ESP and effluent SAR. This showed the dynamic response of effluent irrigated soils to the long-term temporal variation in electrolyte concentration of rainfall/effluent. The relationship between soil ESP and effluent SAR is graphically presented as a continuum, which in turn can be used as a management tool for assessing the potential for dispersion of clay particles in a soil of known ESP and irrigated with waters of known SAR. By identifying trends in the temporal sodium flux, the optimum permeability of the receiving soil can be assessed in relation to the electrolyte concentration of the applied waters and the soil exchangeable sodium percentage (ESP). Secondary treated effluent application rates can then be corrected to prevent “dispersive” irrigation events over the long term and/or management strategies applied to remove excess sodium from the soil profile. The significance of the research is that a better understanding of the temporal dynamics of sodium in the soil profile will allow improved management of effluent irrigated woodlots, with the aim of making the practice sustainable with respect to controlling accumulating soil sodium and maintaining soil structure for future landuse.
PhD Doctorate

This study reports results obtained and the approach taken in investigating the temporal sodium flux in a woodlot soil receiving secondary treated effluent at Branxton, NSW. Previous research has shown woodlot soils receiving secondary treated effluent undergo an increase in exchangeable sodium percentage (ESP) over time. Increased soil ESP influences micro-aggregate/soil pore stability and, particularly when subject to irrigation waters of specific low-electrolyte concentrations, results in decreased soil permeability and a subsequent need to reduce effluent application rates. Therefore, in irrigated woodlot soils it has been necessary to implement strategies to remove excess sodium from the root zone to maintain optimum permeability of the receiving soil, that is, maintaining the cation balance (as soil ESP) to promote optimum soil pore size. To maintain optimum permeability, an understanding is needed of temporal variations in the accumulation/leaching (flux) of sodium within a soil under secondary treated effluent irrigated conditions. The ability to define the sodium flux depends on the frequency of soil sampling and the ability to interpret the net loss/gain in soil sodium in relation to the applied hydraulic load over time. Past research has measured changes in soil ESP on an annual basis, or longer, making it impossible to interpret temporal sodium flux within a given year. The rate of change of soil ESP has ramifications for optimum permeability within an effluent irrigated woodlot. With respect to increasing/decreasing soil ESP, a major response of the clay particles within micro-aggregates is the deformation of conducting soil pores and reduced hydraulic conductivities. In addition, clay dispersion is governed by the soil ESP and electrolyte concentration of the infiltrating waters at the time, where dispersed clay particles may block conducting soil pores and further reduce hydraulic conductivity. Therefore, investigating the temporal sodium flux in conjunction with the temporal variation in electrolyte concentration of infiltrating waters will give greater insight into the response of effluent irrigated soils to sodium-rich waters over time. Three research aims were formed to investigate temporal sodium flux. These include: 1. To investigate trends in the dominant water balance components for a woodlot soil receiving secondary treated effluent (STE); 2. To examine temporal and spatial variation in both the water balance components and measured soil properties, particularly the sodium flux; and 3. To investigate the implications of the sodium flux on the loss of soil structure and drainage over time (dispersion events), particularly in relation to temporal changes in soil ESP and effluent SAR. Monitoring programs for water balance components and soil parameters covered the period January 2002 – October 2003. Every two months, soil samples were taken at designated sites and at different depths (10, 20, 40, 60, and 80 cm). These samples were analysed for exchangeable cations (Ca2+, Mg2+, Na+ and K+), from which the ESP values were derived. Also, this appears to be the first time that soil sampling at this frequency, which enables the temporal sodium flux to be determined, has been carried out. Column leaching experiments were also performed over the study period to illustrate the response of the woodlot soil, in terms of micro-aggregate stability, to hydraulic loads of varying SAR. Column leaching experiments also confirmed the rate of solute movement through the soil profile and the woodlot soil’s ability to bind/exchange sodium under different hydraulic loads and electrolyte concentrations. Soil extraction plate methods were used to determine wilting point and field capacity for these soils. The Sodium Adsorption Ratio (SAR), which is the solutional equivalent to soil ESP, was used to define the electrolyte concentration of the applied effluent and rainfall to the woodlot. The net loss/gain of exchangeable sodium at different depths and times was determined and compared with changes in water balance components and the measured volumetric soil water over time. The soil water surplus/deficit was recorded at a daily time-step and a cumulative approach was used to determine the long-term soil water surplus/deficit. In addition, variations in groundwater levels were monitored to observe if surplus irrigation events were reflected in temporal trends. As a result of determining the temporal variation in soil ESP, effluent and rainfall SAR, daily soil water deficit/surplus (short-term), cumulative soil water deficit/surplus (long-term) and volumetric soil moisture, temporal trends are presented. The sodium flux was then investigated by interpreting trends in the monitored data with respect to the dominant water balance components. All parameters were then used to model the potential dispersive behaviour of the receiving soil over time and depth, in relation to the volume and electrolyte concentration of the effluent and rainfall applied over time. The implications for soil structure and permeability depend on variations in soil ESP and effluent SAR. Results from this research show that soil ESP varied by as much as 24% over a four-month period and is shown to be a function of the sodium loading (from STE) and soil water surplus/deficit. On each sampling occasion, soil ESP generally increased with depth at all irrigated sites. Soil ESP at non-irrigated sites was much lower than irrigated sites, although the variability in soil ESP was much greater. Variations in SAR of the waters received by the woodlot soil (effluent and rainfall) over the study period ranged from 0.5 to 5.9. It is shown that the SAR range, coupled with variations in soil ESP, has ramifications for maintaining long-term soil structure. Soil structure at different sites within a woodlot will respond differently according to the soil ESP/effluent SAR relationship. The dispersive potential of soil at a given ESP receiving irrigation waters of known SAR was assessed in light of the relationship between soil ESP and effluent SAR. This showed the dynamic response of effluent irrigated soils to the long-term temporal variation in electrolyte concentration of rainfall/effluent. The relationship between soil ESP and effluent SAR is graphically presented as a continuum, which in turn can be used as a management tool for assessing the potential for dispersion of clay particles in a soil of known ESP and irrigated with waters of known SAR. By identifying trends in the temporal sodium flux, the optimum permeability of the receiving soil can be assessed in relation to the electrolyte concentration of the applied waters and the soil exchangeable sodium percentage (ESP). Secondary treated effluent application rates can then be corrected to prevent “dispersive” irrigation events over the long term and/or management strategies applied to remove excess sodium from the soil profile. The significance of the research is that a better understanding of the temporal dynamics of sodium in the soil profile will allow improved management of effluent irrigated woodlots, with the aim of making the practice sustainable with respect to controlling accumulating soil sodium and maintaining soil structure for future landuse.
PhD Doctorate

Root-knot nematodes (Meloidogyne spp., RKN) are considered as the most serious nematode pest in the world and have been reported to cause up to 57-67% crop yield losses in untreated conditions in Australia. Chemical control has been the most popular method to manage RKN due to its high efficacy. However, ‘fenamiphos’ the most widely used active ingredient in nematicides, has recently been reviewed by the Australian Pesticides and Veterinary Medicines Authority (APVMA) and subsequently has been recommended for removal from the commercial market in Australia due to concerns about its potential to contribute to adverse environmental and human health impacts. With this pressure of nematicide restrictions, growers in Australia face challenges in controlling RKN in many high-value crops. Therefore, this PhD project focused on identifying alternative strategies to the restricted and currently registered chemical nematicides to control RKN in high-value crops; investigation strategies included use of chemical nematicides, novel organic formulations, organic amendments, biochar, and fungal bio-agents. As the first part of the study, a soil nematode survey was conducted covering the major sweetpotato (Ipomoea batatas (L.) Lam.) growing areas in Queensland (mainly) and New South Wales (Cudgen). Survey results demonstrated that there were ten genera of plant-parasitic nematodes in the survey regions. However, it was identified that RKN is the major pest in the area and that the industry required alternatives to replace chemicals being withdrawn from APVMA registration. The second step was to identify the damage threshold of RKN in sweetpotato, as no study has identified the damage threshold previously. A glasshouse pot trial with sweetpotato (variety Orleans) identified that the damage threshold of RKN could be as low as one RKN/ 200 g dry soil in both ferrosol (loamy) and dermasol (sandy loam) soils. Having this background information, alternative chemical and organic formulations were assessed against RKN in a sweetpotato field trial comparing with untreated control and chemical control ‘oxamyl’ (currently registered chemical for sweetpotato). Fluensulfone significantly reduced soil RKN numbers compared to other treatments, giving the highest marketable yield in this trial. Abamectin did not give significant RKN control or damage reduction. Organic nematicide treatments (garlic formulation and nutrient and microbial formulation) did not show a significant reduction of soil RKN numbers and root damage. No significant effect of nematicides was found on non-target organisms (soil bacteria and nematodes) at 24 weeks after planting. A comprehensive systematic review and meta-analysis were conducted to identify the efficacy of organic amendments against RKN. The meta-analysis identified that organic amendments can reduce RKN numbers and root galling by 63% in general compared to untreated control. A pot trial was conducted with the most effective materials identified in systematic review and meta-analysis as well as with other amendments available to Queensland growers. Amendments used were sugarcane trash, poultry manure, cattle manure based conventional compost, and fermented compost. The experiment found that sugarcane trash applied at 100 t/ ha as the most effective treatment to suppress soil RKN numbers, followed by poultry manure applied at 20 t/ ha and cow manure compost applied at both 20 and 100 t/ ha. Sugarcane trash applied at 100 t/ ha increased undamaged sweetpotato yield; however, there were no significant yield improvements observed for other treatments. The main mechanism of action of the materials probably could be enhanced natural biological suppression of RKN and release of toxic compounds (ammonia from poultry manure). A pot trial was also conducted to evaluate the performance of biochar against RKN in sweetpotato. Biochar (mineralised biochar) was produced from poultry manure and applied at 6.8 t/ ha and 9 t/ ha. Another type of biochar (Nutrient-rich biochar) was produced from mineralised biochar reacting with sweetpotato N, P, and K fertilizer mixture. The low application rate of mineralised biochar significantly reduced soil RKN numbers followed by nutrient-rich biochar. The results demonstrated that there could be a hormesis effect of mineralised biochar to give high suppression of RKN at low application rate. The effect of all biochar treatments on sweetpotato yield was not significant during ten-week experiment. A comprehensive systematic review and meta-analysis were conducted to assess the efficacy of fungal biocontrol agents against RKN in worldwide agricultural crops. This identified that fungal biocontrol generally reduces RKN numbers and root galling numbers by 45% compared to untreated control. Arthrobotrys spp. was observed as an effective genus against RKN based on the present analysis. Arthrobotrys oligospora and A. dactyloides have previously demonstrated biocontrol potential of RKN in sweetpotato; therefore, research was undertaken to produce kaolin-alginate granules incorporated with fungi separately to control RKN. The fungal granules showed 100% RKN trapping activity on agar. A laboratory microcosm system was also developed and used to demonstrate effective RKN trapping by the fungi when granules were applied in dermasol (sandy loam) soil. A pot trial was conducted to find the efficacy of these fungal granules against RKN on ginger (Zingiber officinale Roscoe) in dermasol soil. The treatments were repeated in both heat treated and untreated dermasol soil to assess the effect of natural soil microbiota on the performance of nematode-trapping fungi. Both fungi (incorporated in kaolin alginate granules) were found to be equally effective against RKN at 4 weeks after planting (early growing stages of ginger) similar to the performance of chemical control; however, the performance of fungal granules against RKN was not significant at five months after planting. In addition, the trial confirmed that there was no influence from natural soil microbiota on the performance of fungi during the five-month experiment.

碩士
國立暨南國際大學
管理學院經營管理碩士學位學程碩士在職專班
100
This research mainly takes sustainable development conception and environment education curriculum plan as a goal, and discusses how to unify resources to promote the ecological environment, the natural landscape, the cultural history, the non-toxic agriculture, and the community development in the Toushe peat soil basin leisure agricultural area of Sun Moon Lake region mutually. Using SWOT and TOWS matrix to analyze the internal strengths and weaknesses, external opportunities and threats of Toushe Peat Soil Basin, this study concludes several strategies through environmental resources surveys and interviews. Being the most conducive management of sustainable development for the leisure agriculture areas, the optimal strategy promotes the environmental education of leisure agriculture to implement the existing environmental interpretation, experience courses, and experience-based environmental learning programs in the Toushe peat soil basin leisure agricultural area of Sun Moon Lake region.

Land degradation is a great threat to the Beshlo Catchment in Blue Nile Basisn, not merely as an environmental issue, but also a social and economic problem. In Gedalas Watershed (one of the micro catchments of Beshelo), land degradation, mediated by both biophysical and socio-economic drivers, is among the major environmental sustainability and social-economic development threats in the area. The threat is manifested in depletion of natural vegetations, water, soil and other natural resources; disruption of ecosystem functions, processes, integrity, and services. Given its particular vulnerability, watershed management activities have been in operation since the mid-1970s. Recently, the idea of Sustainable land management through integrated watershed development program has been initiated with the objective of reducing land degradation risks and ensuring food security at both the nationwide and family circle. Despite these investments and efforts, real evidences of success and failures of such efforts were not satisfactory explored. The objectives of this study were, therefore, to analyze the existing status and future prospects of sustainable land management and evaluates its implication on the environmental integrities and the local livelihoods specific to Gedalas watershed. For this effect, the study investigated the dynamics, deriving forces and implications of LULC, soil erosion and soil fertility status of the watershed, current status of watershed management practices, pertinent challenges and opportunities for practicing land management technologies and approaches that might help meet the sustainability requirements of SLM practices. In addition, the study explored factors that determine the willingness of farming households to undertake SLM practice. As the study carried in the coupled human-environment system of rural landscapes, interdisciplinary geographical approaches which integrats social and natural science methodologies were employed to deal with issues of land degradation-and-rehabilitation status comprehensively. The general findings of the study show that though it would be dificult to measure all the composite aspects of land degradation, some of the parameters considered in this study revealed that land degradation is a perpetuating challenge in the watershed. It is evidenced from the overall undesirable land use/cover changes i.e transition of 21.25% of Afro/sub alpine landscapes, 17.59% of the grasslands and 8% of shrub lands to either to cultivated land or settlement areas over the 1973–2017 period, which have unintended negative socio-ecological repercussions on the watershed; high annual mean soil loss value (which range from 37t/ha/year average values to 393 t/ha/yr soil loss rates on water courses) that exceed threshold level and a wide gap between the need for SLM and the actual achievement of SLM practices,including limited adherence to the idea behind contemporary land management policies and implementation principles and approaches. The study further revealed the presence of opportunities as well as a myriad of challenges that need to be tackled in order to achieve sustainable land management goals. The study colcludes that, though, some encouraging progresses have been observed in the SLM project sites; land degradation has remained a problem in the watershed. This calls for strenuous efforts to promote and assist wide scale adoption of SLM practices that address the pervasive land degradation problem and achieve land degradation neutrality as highlighted in sustainable development goals.
Department of Geography
Ph. D. (Geography)