Academic literature on the topic 'Arable cropping'

A mathematical sector model has been formulated to optimize the cropping pattern in Saudi Arabia aiming at maximizing the net annual return of the agricultural sector in Saudi Arabia and ensuring the efficient allocation of the scarce water resources and arable land among the competing crops. The results showed the potential for Saudi Arabia to optimize its cropping pattern and to generate an estimated net return equivalent to about 2.42 billion US$ per year. The optimized cropping pattern in Saudi Arabia has been coupled with about 53% saving in the water use and about 48% reduction in the arable land use compared to the base-year cropping pattern. Comparable weights was given to different crop groups by allocating about 48.4%, 35.4%, 13.1%, and 3.2% to grow cereals, fruits, forages, and vegetables, respectively. These findings were in line with the national strategy to rationalize the cultivation of water-intensive crops in favour of highly water-efficient crops.  

This study presents soil system budgets of N, P and K in six contrasting cropping systems during 10 years of a long-term experiment in southeast Norway. The experiment included systems with arable cash-cropping and with mixed arable-dairy cropping (cash- and fodder crops), with organic and conventional management represented in both groups. All major nutrient inputs and outputs were measured or estimated. State of the art conventional cash-cropping appeared to be balanced in terms of N, whereas conventional mixed cropping had an N surplus. By contrast, less up to date conventional arable cash-cropping and all the organic systems showed indications of soil organic N depletion (negative N budgets). All the organic systems showed that mining of the soil P and K content occurs, whereas the conventional systems all had P and K surpluses. The results corresponded well with measured differences between systems in terms of ignition loss, P-AL, K-AL and K-HNO3measured in 2009. This study shows that a fertile soil may be exposed to substantial mining of N, P and K over many years before it is detectable by traditional analyses, and that field nutrient budgeting is a feasible, but data-demanding, approach to detect such misbalances at an early stage.

Quantification of soil physical quality (SPQ) and pore size distribution (PSD) can assist understanding of how changes in land management practices influence dynamics of soil structure, and this understanding could greatly improve the predictability of soil physical behavior and crop yield. The objectives of this study were to measure the SPQ index under two different land management practices (the continuous arable cropping system and natural bush fallow system), and contrast the effects of these practices on the structure of PSD using soil water retention data. Soil water retention curves obtained from a pressure chamber were fitted to van Genuchten’s equation, setting m (= 1-1/n). Although values for soil bulk density were high, soils under the continuous arable cropping system had good SPQ, and maintained the capacity to support root development. However, soils under the natural bush fallow system had a worse structure than the continuous arable system, with restrictions in available water capacity. These two management systems had different PSDs. Results showed the inferiority of the natural bush fallow system with no traffic restriction (which is the common practice) in relation to the continuous arable cropping system in regard to physical quality and structure.

AbstractRuminant production systems in developing countries could be classified into three categories: the extensive systems, systems incorporating arable cropping and systems integrated with tree cropping. Systems have evolved in response to the agro-ecological environment, the availability and type of land, nature of cropping patterns, frequency and intensity of cropping, area of uncultivated land and animal species and animal numbers.Smallholder livestock farmers in most developing countries appear to have adopted a mixed system that incorporates the traditional extensive system and the system that combines arable cropping with livestock. Both in Africa and in Asia, livestock production is an important component of traditional agriculture, complementing arable cropping. Livestock utilize existing food resources such as communal grazing lands which are marginal for arable cropping, crop residues and agro-industrial by-products. Besides supplying meat and milk, organic manure and draft power, livestock are an investment and an insurance against crop failure.Crop residues and agro-industrial by-products are a major source of nutrients for ruminant livestock in developing countries, especially during periods of fodder shortage. Despite the large research effort on upgrading crop residues in recent years, there has been little improvement in the utilization of crop residues in developing countries. Reasons for this are many but include, the absence of detailed production patterns of crop residues within countries, including when and where they are produced, the difficulties of transporting and storing crop residues, inappropriate technology and the near absence of extension services.Both in the African and Asian continents, smallholder farmers who rear livestock for supplementary income are rather reluctant to change their traditional practices, when new technologies call for extra labour, time and capital, since the methods may be too demanding in relation to the benefit produced. The more likely application of any new technology will be with larger-scale operations where benefits are clearer and sufficiently large to warrant the extra efforts.

AbstractThe predominance of tree crops among abundant, well-preserved plant food remains from coastal sites in southern Belize suggests that these island Maya had a specialized subsistence focus. Limited arable land on offshore islands, together with a maritime economy, may have been important factors in the use of tree crops. The Wild Cane Cay Maya utilized a variety of native palm fruits – Orbignya cohune, Acrocomia mexicana, and Bactris major, as well as other wild tree fruits, in addition to corn. These coastal data support the view that specialized adaptation to diverse environments was a feature of ancient Maya subsistence.

The objective of this study was to determine the impact of a range of management systems on weed communities in cropped fields on farms in Saskatchewan. Farms (n = 28) with management systems defined by a combination of different cropping histories and chemical input levels were selected. Fields were surveyed on each farm in 1995, 1996, and 1997 after any post-emergent weed control to ensure that their weed communities reflected the impact of all agronomic management practices typical of the management system. Canonical correspondence analysis was used to determine whether weed communities were significantly correlated with management system after removal of variance due to ecoregion and year. The largest difference in weed communities attributable to farming system was between the systems with annual cropping histories and those that included perennials in the cropping history. Thus, the life history of the weeds reflected the life history of the crops. Herbicide use was correlated with the next largest difference between systems. A significant association between weed communities and different management systems indicates that weed species are being selected for by these systems. If such selection pressure continues, these species may become a threat to the system's sustainability. Key words: Weed communities, chemical input level, cropping history, canonical correspondence analysis, correspondence analysis, farming system

Background Tree-based intercropping (agroforestry) has been advocated to reduce adverse environmental impacts of conventional arable cropping. Modern agroforestry systems in the temperate zone are alley-cropping systems that combine rows of fast-growing trees with rows of arable crops. Soil microbial communities in these systems have been investigated intensively; however, molecular studies with high taxonomical resolution are scarce. Methods Here, we assessed the effect of temperate agroforestry on the abundance, diversity and composition of soil bacterial communities at three paired poplar-based alley cropping and conventional monoculture cropland systems using real-time PCR and Illumina sequencing of bacterial 16S rRNA genes. Two of the three systems grew summer barley (Hordeum vulgare); one system grew maize (Zea mays) in the sampling year. To capture the spatial heterogeneity induced by the tree rows, soil samples in the agroforestry systems were collected along transects spanning from the centre of the tree rows to the centre of the agroforestry crop rows. Results Tree rows of temperate agroforestry systems increased the abundance of soil bacteria while their alpha diversity remained largely unaffected. The composition of the bacterial communities in tree rows differed from those in arable land (crop rows of the agroforestry systems and conventional monoculture croplands). Several bacterial groups in soil showed strong association with either tree rows or arable land, revealing that the introduction of trees into arable land through agroforestry is accompanied by the introduction of a tree row-associated microbiome. Conclusion The presence of tree row-associated bacteria in agroforestry increases the overall microbial diversity of the system. We speculate that the increase in biodiversity is accompanied by functional diversification. Differences in plant-derived nutrients (root exudates and tree litter) and management practices (fertilization and tillage) likely account for the differences between bacterial communities of tree rows and arable land in agroforestry systems.

The study analysed factors influencing arable crop farmers’ willingness to adopt bio-organic technology in Ondo State. Multi-stage sampling procedure was used to select 180 respondents for the study. Questionnaire was used to collect data which were analysed with percentages, 4-point likert-type scale and logit regression model. The findings revealed that the females (67.0%) dominated arable crop farming, the mean age was 41 years and 55.6% had formal education. All the respondents are aware of mixed cropping and croprotation and less than 50% were aware of alley cropping (43.2) and biological pest control (26.6). The majority (67.6%) of the arable crop farmers had unfavourable perception of bio-organic technology. The study showed that increase in extension visit, membership of farmers’ group, access to information and education positively increase the likelihood of farmers to adopt bio-organic technology. Enhanced extension services that would adequately support farmer and extended education programs geared towards broadening farmers’ knowledge on bio-organic technology should be promoted. Keywords: willingness, adoption, bio-organic technology, arable crop farmer

Riveting is a traditional joining technique mostly used in the manufacturing of aircraft structures. Manufacturing studies on the next generation of wide body commercial aircraft have' indicated that the achievement of acceptable cost/benefit goals would require the» application of highly cost-effective joining processes. Although riveting provides good structural performance, it is expensive and time consuming. Welding is a candidate process t be used to manufacture large aircraft structures allowing sensible cost reductions and structural efficiency. Welded aluminium 2024-T351 structural joints produced .with a new generation of welding processes, such a Friction Stir Welding ( SW) and Plasma welding were characterised in terms of rnicrostructure, hardness and weld residual stress. Tensile properties and stress-strain behaviour of the FSW joints was investigated and discussed using simple mechanical models. The investigation of the fatigue properties of the FSW and Plasma Welded structural joints revealed the superior behaviour of the FSW joints. It was found that fatigue strength in FSW joints is dominated by surface irregularities produced by the welding process. Weld surface skimming greatly improved fatigue strength by removing surface stress concentrations. Initiation in skimmed joints occurred at locations of minimum hardness. Fatigue endurance behaviour of skimmed joints was equal or superior to that reported in riveted aluminium joints. Fatigue crack propagation studies were carried out on FSW 2024-T351 joints for cracks parallel and orthogonal to the weld direction. Crack propagation behaviour was sensitive t both weld orientation and the distance of the crack from the weld line. Growth rates both faster and slower than in the parent material were observed, depending on the crack orientation and distance from the weld. Residual stress was mechanically relieved and the effects on crack propagation observed. A comparative analysis of the results associated with crack closure measurements indicated that crack growth behaviour in the FSW joints was generally dominated by the weld residual stress. Possible design solutions for damage tolerant Welded aircraft structural components were identified and discussed in the light of the experimental results.

"The application of bio-solids to established arable crops, using shallow injection techniques developed during this study, is feasible in environmental, economic,agronomic and engineering terms." Novel approaches to bio-solids disposal and recycling are required to compensate for expected increases in production, and to alleviate the extemal pressures exerted on the water company through legislation and increased public awareness of environmental issues. A review of previous work has identied bio-solids application to arable cropping as a promising benecial outlet for increased volumes of waste. From this doctoral study, in collaboration with a parallel fast track project, a improved, shallow injection system has been developed, based on soil mechanics theory and extensive laboratory and field testing. Environmental pollution, in terms of odour and ammonia emissions, may be signicantly reduced through the use of this system, when compared to other shallow injection or surface application methods. Nitrate leaching was found to be unaffected by the increased retention of valuable nutrients under field conditions prevailing during the study period, and no detrimental effect on agronomic performance has been identied following application to crops up to three months prior to harvest. Economically, a market exists for this technology, through the enhanced nutrient value of the bio-solids product. However, product quality, consistency and other enviromnental issues require solutions before the full economic benefits and market acceptance can be realised. Theoretically, the increased application "window of opportunity" has the potential to increase producers operating profits substantially (1.7%/yr, Anglian Water Services Region) through reduced inventory, storage and distribution costs. Maximisation of enviromnental benefits has been addressed in terms of implement control, by maintaining constant tine attitude to the soil, through a parallel linkage system. A analysis of the force system associated with the parallel lirkage system, in conjunction with the development of a model to predict tine depth, was used to examine ways of optimising the dynamic performance of the system. This work demonstrated that geometric changes to the parallel linkage are unlikely to affect dynamic performance. However, the use of frictionless linkage joints in conjunction with depth control skids was shown to improve dynamic performance signicantly and a novel multiple curve fitting technique was developed to improve the accuracy of the depth prediction model.

Accelerated soil erosion affects sustainable food production through the degradation of arable soils resulting in lower crop yields and compromising biodiversity. Over the past 50 years, the weed seedbank has been declining due to farming intensification, increased herbicide use and weed suppression through competitive autumn crop planting. However, there is less recognition of the potential of soil erosion affecting the weed seedbank. This thesis contributes to an improved understanding of the effect of geomorphological processes (soil erosion) on biological systems (weed seedbank) in arable ecosystems. The first investigation assessed whether the management of farm machinery field tramlines would decrease soil erosion rates and effect the movement of weed seeds. Over three winter seasons, eroded material was collected by a network of Gerlach Troughs. The results showed that tramline management with a spiked harrow decreased soil and seed loss by 93.9% and 86.56% respectively, compared to regular tyre tramlines. Analysis of seed data to runoff and sediment load found seeds were transported along with sediment (r²=0.62) rather than runoff (r2=0.2) over the long term. In addition, tramline management significantly affected the number of seed species transported (p<0.001), which was found to relate to seed morphologies. Overall, tramlines cause 0.01% - 0.32% seed fluxes annually depending on management. These findings have implications for farmers to protect tramlines from erosion and displace seeds through management thereby, preventing the loss of biodiversity within the field. The second investigation looked at the movement of weed seeds at the field scale by erosion through the use of a radionuclide (¹³⁷Cs) tracer. A single field was sampled for seedbank and soil cores taken for ¹³⁷Cs analysis in two sub field grids. The results indicated weak relationships between seedbank densities and erosion. The weak relationships in the grids (r² =0.13, p =0.029 in 2011 and r² =0.12, p = 0.036) were due to land management contributing to spatial variability within seedbank abundance and composition. Individual species showed mixed responses to erosion rates. The findings indicate farmers need to consider management strategies at field scale to effectively manage erosion and seedbanks because seedbank losses of between 2 – 2.5 % annually within the field which is linked to field scale sediment budgets. The third investigation looked at specific environmental controls that would affect soil erosion and seedbanks. This was achieved by using a portable rainfall simulator on plots containing either seeds from the natural seedbank or spiked with seeds. The key control was the presence of crop/vegetation cover in affecting erosion rates (p<0.001) and seed movement (p = 0.001). The presence of crop cover resulted in low erosion rates but a greater loss of seeds compared to plots with no crop cover. This was linked to vegetation cover providing a protective environment for weeds to grow and produce additional seeds via seed rain. Ground cover prevents erosion but also highlighted seed movement was higher than on bare soil due to a greater availability. This means that surface wash is more important than rainfall in causing seed transport. For spiked plots, more seeds were displaced in short (3 minute) events compared with long (6 minute) events (p = 0.04). This shows protecting the soil and seedbank from rainfall detachment is crucial to preventing transport of sediment and seeds that could enter other transport pathways (e.g. tramlines, rills, gullies). The fourth investigation looked into the processes and impacts of soil erosion on seedbanks at the catchment scale. This was done by establishing a monitoring station at the outlet of an arable catchment for one year to monitor discharge, suspended solids and seed flux. The results of monitoring in 2012 found seeds numbers were positively related to discharge (observed r² = 0.62, p<0.001; observed plus modelled r²=0.50, p <0.001) and sediment load (observed r² = 0.64, p<0.001; observed plus modelled r2= 0.89, p<0.001). Seed species had poor negative relationships with discharge (observed r² = 0.03, p=0.357; observed plus modelled r²=0.11, p = 0.017) and sediment load (observed r² <0.001, p=0.352; observed plus modelled r²=0.14, p=0.004). An initial estimate of losses from the catchment was around 0.008 – 0.027% of the weed seedbank. Interestingly, there appeared to be a trend in the abundance of seed collected relating to patterns of farming activity within the catchment. This finding has management implications as there is evidence, for the first time, of arable weed seeds being exported from the catchments, which could affect other agricultural land and ecosystems downstream. The findings of these four investigations showed that the effect of soil erosion on the seedbank is connected at different spatial scales. Scope for future work is to improve the understanding of the role of seed morphologies, land management and field scale processes affecting the transportability of seeds by erosion processes.

La coltivazione dei sistemi colturali poliennali su terreni marginali combina la produzione sostenibile di biomassa per diversi utilizzi a benefici di carattere ambientale come il sequestro del C atmosferico nel suolo. La limitata longevità di questi sistemi colturali (10-20 anni), fornisce la possibilità di sfruttarli come una tecnica temporanea per rigenerare la fertilità dei terreni marginali e di studiare il loro effetto nel lungo periodo sul carbonio del suolo. Con questa tesi, avevo l'obiettivo di studiare l'effetto della riconversione a coltura annuali dei sistemi agricoli poliennali sul carbonio del suolo: per raggiungere questo obiettivo, ho combinato ad una meta-analisi di letteratura sull'effetto della riconversione, con un esperimento di campo di lungo periodo, un esperimento di incubazione in laboratorio e l'uso di un modello matematico del carbonio del suolo. L'uso combinato di questi approcci mi ha permesso di mostrare il potenziale che i sistemi colturali poliennali hanno nel sostenere il sequestro del C ne suolo anche dopo la loro riconversione. Quindi i sistemi colturali poliennali sono una pratica sostenibile promettente che può essere integrata in rotazioni agricole di 13 anni sui terreni marginali del nord d'Italia per ripristinare il carbonio del suolo.
The cultivation of perennial cropping systems on marginal lands combines the production of sustainable biomass for multiple uses with environmental benefits such as carbon (C) sequestration in soil. In this thesis, we studied the effect of perennial cropping system on soil C considering the scenario of perennial cropping systems reversion to arable land. The limited longevity (10-20 years) of perennial cropping systems, gives the possibility of using these crops as a temporary- option to restore soil fertility of marginal lands and to study the long-term legacy of these cropping systems on soil C. In this thesis I aimed to study the effect of perennial cropping systems reversion to arable land on soil C: to achieve this objective, I combined a literature meta-analysis on the effect of reversion of perennial cropping systems on soil C, with a long-term field experiment on perennial cropping systems, an incubation experiment and the use of a process-based soil C model. The combined use of these approaches gave me the chance to show the potential of perennial cropping systems to support C sequestration even after their reversion. Therefore, perennial cropping systems are a promising sustainable practice which could be integrated on a 13-year agricultural rotation on marginal lands of northern Italy to restore soil C.

Arable crop production in Nkonkobe Municipality is low due to abandonment of potentially productive land and low productivity of the cultivated land. Little attention has been given to farmers perspectives with regards to crop production and land abandonment. Understanding the relationships of indigenous knowledge systems, where local approaches to soil classification, appraisal, use and management and land evaluation, and scientific approaches could be important for the effective use of available soil resources while avoiding those resources that are vulnerable to degradation. In addition, the interactions between soil factors and climate could be useful in understanding the erodibility of soils. The intergration of scientific research and indigenous knowledge systems could help in the identification and delineation of high potential land and on crop suitability evaluation. The objectives of the study were: (i) to determine farmers‟ perspectives with regards to land utilisation and abandonment, constraints on crop production and crop preferences, (ii) to integrate and compare indigenous knowledge systems with scientific approaches of soil classification and potential, (iii) to determine the effect of climate and soil factors on erodibilities of soils in the Municipality (iv) to delineate arable land and evaluate its suitability for maize, potato, sorghum and cowpea under rainfed agriculture. Using semi-structured and open-ended interviews, information on limitations to crop production, cropping preferences, indigenous soil classifications, cropping potential ratings and erosion was captured. Descriptive and correlation statistics were used to analyse farmers‟ responses. The information was later used for a pilot participatory mapping and the determination of the agricultural potential of the soils in three selected villages of the Municipality. Field boundaries of soil texture, colour, depth, and slope position were captured using global positioning systems (GPS). The relationship between the degree of erosion and soil and slope factors was analysed by step-wise regression. Crop suitability for rainfed agriculture was done using the FAO guidelines for Land evaluation for rainfed agriculture. The spatially referenced crop suitability classes were produced by applying the Law of Limiting Combinationusing GIS Boolean Logic. The major biophysical factors, affecting crop production and land utilisation were soil degradation and low and erratic rainfall, while other factors included lack of farming equipment and security concerns. Maize, spinach and cabbage were the main crops grown, with maize sorghum and wheat the most abandoned crops. While it was difficult to accurately correlate indigenous classification with international scientific classification, the importance of colour, texture and soil depth for both classification and soil potential, suggests that some form of correlation is possible which enabled communication and other extension information to be conveyed. The shallow and stony soil (urhete) correlated well with the Leptosols in World Reference Base (WRB) or Mispah and shallow Glenrosa soils in the South African system. The red structured clays (umhlaba obomvu) matched the Nitisols in WRB or Shortlands in the South African system. The non-swelling black clayey soils (umhlaba omnyama) matched soils with melanic A horizons in both the WRB and South African soil classification systems. The dongwe and santi soils developed in alluvial sediments belonged to the Dundee, Oakleaf or Augrabies soils in the South African classification system and fluvisols or Cambisols in the WRB system. There was good agreement between farmers assessment of the cropping potential and scientific approaches but scientifically high potential red soils were rated lowly by the farmers due to difficulties in management caused by shortages of farm machinery, especially under dryland farming. Overall, the soil factors affecting erosion were influenced largely by climate, while parent material was also important. Climate had a dominant influence on soil factors most notably fine sand and very fine sand fractions and exchangeable sodium percentage being more important on soil forms occurring in arid and semi-arid climate and less in the sub-humid and humid areas, where clay mineralogy, particularly kaolinite and sesquioxide dominated. Dolerite derived soils were the most stable and should be given the highest priority for cropping development while mudstone and shale derived soils had a lower cropping potential. While slope gradient and length had some effect on soil erosion in arid and semi arid environments its influence was generally overshadowed by soil factors especially in humid zones. Cow pea and sorghum were the most adapted crops in the region while potato and maize were marginally suitable under rainfed agriculture. The study revealed that most adapted crops were not necessarily the most preferred crops by the farmers. A small percentage of the land was delineated as arable and therefore optimisation of this available land should be prioritized.

The incorporation of cereal straw/stubble often immobilises nitrogen (N). This can help conserve N in soil in organic forms, thus reducing loss through leaching over dormant winter periods. However, N-depressions that arise during decomposition can reduce crop yield. The inclusion of a legume green manure can supply fixed-N, thus alleviating the low N availability to crops. In this study, the effect of lupin (Lupinus angustifolius L.) green manure incorporation on barley (Hordeum vulgare L.) straw/stubble decomposition, and N availability was investigated. A field experiment was used to determine the effects of the green manure on decomposition. Decomposition of straw/stubble was monitored using the litterbag technique. Following green manure incorporation, soil cores were incubated in a glasshouse to determine mineral-N availability. Though not significant, the inclusion of lupin green manure seemed to increase the decomposition of straw/stubble during the growth period, then slowing it after its incorporation at 110 d. This was described by a logarithmic pattern of loss of - 4.97 g AFDW residue day⁻¹, with 60% remaining after 140 d. Treatments without lupin had a linear decomposition of - 0.12 g AFDW residue day⁻¹, with 49% remaining after 140 d. The loss of cellulose confirmed the differences in decomposition with the inclusion of lupin resulting in 2.79% less cellulose remaining in straw/stubble after 140 d compared to its exclusion. Lupin significantly increased pot oat N uptake and DM yield by 55 % and 46 %, respectively, compared to its exclusion. However, this effect was not observed in field sown wheat yields and the soil mineral-N measurements made. This study showed that the potential of lupin to increase straw/stubble decomposition by improving the retention and availability of N, leading to long-term yield benefits, needed further investigation.

Modern agriculture is the basis of human existence, a blessing, but also a curse. It provides nourishment and well-being to the ever-growing human population, yet destroys biodiversity-mediated processes that underpin productivity: ecosystem services such as water filtration, pollination and biological pest control. Ecological intensification is a promising alternative to conventional farming, and aims to sustain yield and ecosystem health by actively managing biodiversity and essential ecosystem services. Here, I investigate opportunities and obstacles for ecological intensification. My research focuses on 1) the relative importance of soil, management and landscape variables for biodiversity and wheat yield (Chapter II); 2) the influence of multi-scale landscape-level crop diversity on biological pest control in wheat (Chapter III) and 3) on overall and functional bird diversity (Chapter IV). I conclude 4) by introducing a guide that helps scientists to increase research impact by acknowledging the role of stakeholder engagement for the successful implementation of ecological intensification (Chapter V). Ecological intensification relies on the identification of natural pathways that are able to sustain current yields. Here, we crossed an observational field study of arthropod pests and natural enemies in 28 real-life wheat systems with an orthogonal on-field insecticide-fertilizer experiment. Using path analysis, we quantified the effect of 34 factors (soil characteristics, recent and historic crop management, landscape heterogeneity) that directly or indirectly (via predator-prey interactions) contribute to winter wheat yield. Reduced soil preparation and high crop rotation diversity enhanced crop productivity independent of external agrochemical inputs. Concurrently, biological control by arthropod natural enemies could be restored by decreasing average field sizes on the landscape scale, extending crop rotations and reducing soil disturbance. Furthermore, reductions in agrochemical inputs decreased pest abundances, thereby facilitating yield quality. Landscape-level crop diversity is a promising tool for ecological intensification. However, biodiversity enhancement via diversification measures does not always translate into agricultural benefits due to antagonistic species interactions (intraguild predation). Additionally, positive effects of crop diversity on biological control may be masked by inappropriate study scales or correlations with other landscape variables (e.g. seminatural habitat). Therefore, the multiscale and context-dependent impact of crop diversity on biodiversity and ecosystem services is ambiguous. In 18 winter wheat fields along a crop diversity gradient, insect- and bird-mediated pest control was assessed using a natural enemy exclusion experiment with cereal grain aphids. Although birds did not influence the strength of insect-mediated pest control, crop diversity (rather than seminatural habitat cover) enhanced aphid regulation by up to 33%, particularly on small spatial scales. Crop diversification, an important Greening measure in the European Common Agricultural Policy, can improve biological control, and could lower dependence on insecticides, if the functional identity of crops is taken into account. Simple measures such as ‘effective number of crop types’ help in science communication. Although avian pest control did not respond to landscape-level crop diversity, birds may still benefit from increased crop resources in the landscape, depending on their functional grouping (feeding guild, conservation status, habitat preference, nesting behaviour). Observational studies of bird functional diversity on 14 wheat study fields showed that non-crop landscape heterogeneity rather than crop diversity played a key role in determining the richness of all birds. Insect-feeding, non-farmland and non-threatened birds increased across multiple spatial scales (up to 3000 m). Only crop-nesting farmland birds declined in heterogeneous landscapes. Thus, crop diversification may be less suitable for conserving avian diversity, but abundant species benefit from overall habitat heterogeneity. Specialist farmland birds may require more targeted management approaches. Identifying ecological pathways that favour biodiversity and ecosystem services provides opportunities for ecological intensification that increase the likelihood of balancing conservation and productivity goals. However, change towards a more sustainable agriculture will be slow to come if research findings are not implemented on a global scale. During dissemination activities within the EU project Liberation, I gathered information on the advantages and shortcomings of ecological intensification and its implementation. Here, I introduce a guide (‘TREE’) aimed at scientists that want to increase the impact of their research. TREE emphasizes the need to engage with stakeholders throughout the planning and research process, and actively seek and promote science dissemination and knowledge implementation. This idea requires scientists to leave their comfort zone and consider socioeconomic, practical and legal aspects often ignored in classical research. Ecological intensification is a valuable instrument for sustainable agriculture. Here, I identified new pathways that facilitate ecological intensification. Soil quality, disturbance levels and spatial or temporal crop diversification showed strong positive correlations with natural enemies, biological pest control and yield, thereby lowering the dependence on agrochemical inputs. Differences between functional groups caused opposing, scale-specific responses to landscape variables. Opposed to our predictions, birds did not disturb insect-mediated pest control in our study system, nor did avian richness relate to landscape-level crop diversity. However, dominant functional bird groups increased with non-crop landscape heterogeneity. These findings highlight the value of combining different on-field and landscape approaches to ecological intensification. Concurrently, the success of ecological intensification can be increased by involving stakeholders throughout the research process. This increases the quality of science and reduces the chance of experiencing unscalable obstacles to implementation
Die moderne Landwirtschaft ist die Grundlage menschlichen Lebens, ein Segen, aber auch ein Fluch. Sie stellt Nahrung und Wohlstand für die immerfort wachsende menschliche Bevölkerung bereit, und zerstört gleichzeitig Biodiversitäts-geförderte Prozesse, welche die Produktivität unterstützen: Ökosystemdienstleistungen wie Wasseraufbereitung, Bestäubung und biologische Schädlingsbekämpfung. Ökologische Intensivierung ist eine vielversprechende Alternative zur konventionellen Landwirtschaft, und zielt darauf aus, Erträge und die Gesundheit von Ökosystemen zu erhalten indem Biodiversität und essentielle Ökosystemdienstleistungen aktiv gemanagt werden. In meiner Doktorarbeit untersuche ich die Chancen und Hürden Ökologischer Intensivierung. Das Hauptinteresse meiner Forschung liegt bei 1) der relativen Bedeutung von Boden, Bewirtschaftung und Landschaftsaspekten für Biodiversität und Weizenerträge (Kapitel II); 2) dem Einfluss regionaler Anbauvielfalt auf verschiedenen räumlichen Skalen auf die biologische Schädlingsbekämpfung in Weizen (Kapitel III) und 3) auf die gesamte und funktionelle Artenvielfalt von Vögeln (Kapitel IV). Zum Schluss 4) stelle ich einen Leitfaden vor, der Wissenschaftlern hilft die Wirkung ihrer Forschung zu erhöhen, indem die fundamentale Rolle von Stakeholdern für die Umsetzung Ökologischer Intensivierung besser genutzt wird (Kapitel V). Ökologische Intensivierung bedarf der Identifizierung von natürlichen Prozessen, die zum Erhalt landwirtschaftlicher Erträge beitragen. Zu diesem Zweck verknüpften wir eine Beobachtungsstudie, in der Schädlinge und natürliche Gegenspieler in 28 realen Weizen Anbausystem aufgenommen wurden, mit einem orthogonalen Feldexperiment (Insektizid und mineralische Düngung). Anhand einer Pfadanalyse quantifizierten wir den Einfluss von 34 Faktoren (Bodencharakteristiken, gegenwärtige und vergangene Bewirtschaftung, Landschaftsheterogenität), die direkt oder indirekt (über Räuber-Beute-Interaktionen) Einfluss auf den Winterweizenertrag ausüben. Reduzierte Bodenbearbeitung und vielfältige Fruchtfolgen erhöhten die Erträge unabhängig von der Ausbringung von Agrochemikalien. Gleichzeitig könnte die biologische Schädlingsbekämpfung durch räuberische Insekten wiederhergestellt werden, indem durchschnittliche Schlaggrößen auf der Landschaftsebene verringert, Fruchtfolgen erweitert und die Bodenbearbeitung reduziert wird. Des Weiteren senkte der Verzicht auf Agrochemikalien das Schädlingsaufkommen einiger Arten, und trug zu einer höheren Ertragsqualität bei. Regionale Anbauvielfalt ist ein vielversprechendes Mittel zur Ökologischen Intensivierung. Doch die Erhöhung der Artenvielfalt durch Diversifizierungsmaßnahmen führt nicht immer zu Vorteilen in der Landwirtschaft, vor allem auf Grund antagonistischer Wechselwirkungen zwischen verschiedenen Arten (intraguild predation). Weiterhin können positive Effekte der Anbauvielfalt durch die Wahl der falschen räumlichen Skala oder durch Korrelationen mit anderen Landschaftsvariablen (z.B. halbnatürliche Habitate) überdeckt werden. Aus diesem Grund bestehen Unklarheiten über die Wirkung von Anbauvielfalt auf Biodiversität und Ökosystemdienstleistungen in unterschiedlichen räumlichen Skalen und Kontexten. Durch Ausschlussexperimente mit Getreideblattläusen untersuchten wir die biologische Schädlingsbekämpfung durch räuberische Insekten und Vögel in 18 Winterweizenfeldern innerhalb eines Landschaftsgradienten der Anbauvielfalt. Vögel hatten keinen Einfluss auf die biologische Schädlingsbekämpfung durch Insekten. Anbauvielfalt (nicht das Vorkommen halbnatürlicher Habitate) erhöhte die Schädlingsbekämpfung um bis zu 33%, vor allem auf kleinen räumlichen Skalen. Somit kann die Steigerung der Anbauvielfalt, eine wichtige Säule der Europäischen Gemeinsamen Agrarpolitik, die biologische Schädlingsbekämpfung verbessern und den Einsatz von Agrochemikalien verringern, solange die funktionelle Gruppe der Anbaupflanzen berücksichtigt wird. Einfache Maßeinheiten wie die ‘effektive Anzahl an Kulturpflanzengruppen‘ helfen in der Kommunikation wissenschaftlicher Ergebnisse. Obwohl die Schädlingsbekämpfung durch Vögel nicht durch regionale Anbauvielfalt beeinflusst wurde, könnten Vögel, abhängig von der Zugehörigkeit zu bestimmten funktionellen Gruppen (Ernährung, Gefährdungsstatus, Lebensraum, Nistplatzwahl), dennoch von erhöhten Ressourcen auf landwirtschaftlichen Flächen profitieren. In einer Beobachtungsstudie wurde die funktionelle Vielfalt von Vögeln auf 14 Winterweizenfeldern aufgenommen. Die Studie zeigte, dass die nicht agrarisch genutzte Landschaftsheterogenität im Vergleich zur regionalen Anbauvielfalt eine übergeordnete Rolle für die Artenvielfalt spielte, vor allem für Insektenfresser, Vögel die außerhalb landwirtschaftlicher Flächen siedeln oder nicht in ihrem Bestand gefährdet sind. Effekte waren auf allen Skalen sichtbar (bis zu 3000m). Nur Acker-nistende Agrarvögel zeigten negative Beziehungen zu Landschaftsheterogenität. Der Nutzen der Anbaudiversifizierung scheint weniger Bedeutung für den Vogelschutz zu haben als die übergeordnete Vielfalt der Landschaft, welche den Artenreichtum häufiger Vogelarten erhöhte. Spezialisierte Vogelarten dagegen bedürfen eines gezielten, angepassten Managements. Um Ökologische Intensivierung voranzutreiben und ein Gleichgewicht zwischen Naturschutz- und Produktivitätszielen zu erreichen, bedarf es der Identifikation ökologischer Prozesse, die zur Steigerung von Biodiversität und Ökosystemdienstleistungen beitragen. Doch der die Wende zu einer nachhaltigeren Landwirtschaft wird nur langsam voran schreiten, wenn Forschungsergebnisse nicht global umgesetzt werden. Während der Öffentlichkeitsarbeit im EU Projekt Liberation konnte ich Informationen über die Vor- und Nachteile Ökologischer Intensivierung und deren Umsetzung sammeln. Hier stelle ich einen Leitfaden (‘TREE’) vor, der Wissenschaftlern helfen soll die Wirkung ihrer Forschung zu erhöhen. TREE verdeutlicht wie wichtig es ist, Stakeholder in den Planungs- und Forschungsprozess eines Projektes mit einzubeziehen, und aktiv die Verbreitung von Wissen und die Umsetzung wissenschaftlicher Ergebnisse voranzutreiben. TREE fordert Wissenschaftler dazu auf, die eigene Komfortzone zu verlassen und sozioökonomische, praktische und rechtliche Aspekte zu berücksichtigen, welche oft in der klassischen Forschung unbeachtet bleiben. Ökologische Intensivierung ist ein bedeutender Schritt in Richtung nachhaltige Landwirtschaft. In dieser Arbeit identifiziere ich neue Wege zur ökologischen Intensivierung. Bodenqualität, Störungsgrad des Bodens und die räumliche oder zeitliche Anbauvielfalt zeigten starke positive Korrelationen mit natürlichen Gegenspielern, biologischer Schädlingsbekämpfung und Erträgen auf, wodurch die Abhängigkeit von Agrochemikalien verringert wird. Unterschiede zwischen funktionellen Gruppen verursachten gegensätzliche Beziehungen zu Landschaftsvariablen auf verschiedenen räumlichen Skalen. Entgegen unserer Erwartungen nahmen Vögel in unserem System keinen Einfluss auf die biologische Schädlingsbekämpfung durch Insekten. Die Vogelvielfalt war außerdem unbeeinflusst von der regionalen Anbauvielfalt. Doch dominante funktionelle Vogelgruppen profitieren von der Vielfalt nicht agrarisch genutzter Landschaftsaspekte. Diese Ergebnisse betonen den Wert einer Mischung aus unterschiedlichen lokalen und landschaftsbezogenen Ansätzen zur Ökologischen Intensivierung. Gleichzeitig kann der Erfolg Ökologischer Intensivierung vor allem dadurch erhöht werden, dass Stakeholder in den Forschungsprozess eingebunden werden. Dies steigert die Qualität der Forschung und reduziert die Wahrscheinlichkeit, während der Umsetzung auf unüberwindbare Hürden zu stoßen

AbstractThe use of biomass and biofuels, such as wood, charcoal, petroleum, kerosene, and gas, is becoming competitive based on the level of development of each nation. However, charcoal production (CP) and marketing now tends to be a major business among many households in both rural and urban communities with no consideration of its effects on climate change adaptation. While the research question considers the various definition of climate change adaptation, and the importance of charcoal production in Nigeria, the manuscript speaks mainly of the problems of charcoal production, the lack of planning to address these problems, and the lack of planning to move the communities away from this practice and out of poverty. It addresses the impacts of charcoal production on agriculture, such as lack or loss of labor and destruction of arable lands. The paper discusses the effect of charcoal production on health. Also, the environmental problems of CP are highlighted in the manuscript. The policy frameworks on forestry by the Federal Ministry of Environment 2006 with its flaws will be included. Remedy such as the establishment of a Land Use Planning Agency (LUPAG) and panacea for greening the charcoal value chain issues will be discussed. Lastly, attention is given to the agricultural adaptation strategies to climate change which are capable of reducing charcoal production, such as mixed cropping.

AbstractThe use of biomass and biofuels, such as wood, charcoal, petroleum, kerosene, and gas, is becoming competitive based on the level of development of each nation. However, charcoal production (CP) and marketing now tends to be a major business among many households in both rural and urban communities with no consideration of its effects on climate change adaptation. While the research question considers the various definition of climate change adaptation, and the importance of charcoal production in Nigeria, the manuscript speaks mainly of the problems of charcoal production, the lack of planning to address these problems, and the lack of planning to move the communities away from this practice and out of poverty. It addresses the impacts of charcoal production on agriculture, such as lack or loss of labor and destruction of arable lands. The paper discusses the effect of charcoal production on health. Also, the environmental problems of CP are highlighted in the manuscript. The policy frameworks on forestry by the Federal Ministry of Environment 2006 with its flaws will be included. Remedy such as the establishment of a Land Use Planning Agency (LUPAG) and panacea for greening the charcoal value chain issues will be discussed. Lastly, attention is given to the agricultural adaptation strategies to climate change which are capable of reducing charcoal production, such as mixed cropping.

AbstractA top-bottom approach where local problems are treated in isolation has proven ineffective in achieving sustainable development. The need for inclusive approaches to managing the demand for arable lands, forest resources, and the problems of resource exploitation and climate change calls for local understanding of these elements’ interrelationship. Understanding the interrelationships among climate change, agriculture, and the ecosystems in different agroecological zones in Nigeria was the purpose of this chapter. Deforestation and forest degradation analysis approach was utilized. One state and two forest communities from each of the rainforest, savannah, and mangrove agroecological zones were purposively focused in this chapter based on forest distribution and cover. Focus group discussions involving 252 male and female farmers using 30 years as reference were used to garner relevant information. Climate variation caused a slight modification in cropping schedules of farmers due to prolonged dry season, mainly in the savannah region. Farmers engaged in mixed farming and also cultivate more hardy crops like cassava in response to climate uncertainties. Especially in the mangrove and savannah, ecosystem components such as agriculture and population showed increasing trends over the years as forest cover reduces. Downward trend in charcoal production was limited to mangrove and rainforest zones as fishing and hunting becomes vulnerable livelihoods across the zones. The degree and progression of climate change effects on the ecosystem in Nigeria agroecological zones is largely comparable and have both desirable and adverse livelihood outcomes. Affordable insurance policy, credit, agri-inputs, favorable forest regulatory framework, and youth empowerment supports would enhance sustainable adjustment to climate change.

Crop physiology has been called “the retrospective science” by one plant breeder because we physiologists elucidate what the breeders have already achieved. Indeed, such explanations occupy the first part of this chapter, the whence of greater crop production. We shall also peer ahead, the whither in my title. But physiologists have learned that past increases in crop productivity have often come from unexpected and initially unrecognized directions, in many cases driven by developments in agronomy, mechanization, and demand. The integrating power of empirical selection for yield potential has, so far, proved more effective than ideological selection for specific physiological characteristics, presumably because yield is the integrated end result of a great variety of processes that must act in a balanced and coordinated way. Crop production can be increased in several ways, such as by extending the arable area, by increasing yield per hectare per crop or the number of crops per hectare per year (called intensification), by displacement of lower by higher yielding crops, and by reducing postharvest losses. Until the 1960s the major contribution for the world as a whole came from increases in the area of arable land and in the proportion of it under crop. Since then, however, the limited increases in arable area, in South America and Africa mostly, have largely been matched —though not in land quality —by losses to urbanization, transport, and degradation. The proportion of rainfed arable land under crop continues to increase slowly, currently being about three quarters for the developing countries as a whole. The intensification of arable land use is most important in warmer and wetter climates, particularly under irrigation. Double cropping of rice has been prominent in China since Sung times. Cropping intensity in the Punjab now approaches 200%, and FAO projects that 13% of the increase in crop production in developing countries by A.D. 2010 will come from intensification, compared with 21% from extension of the arable (Alexandratos, 1995). Further intensification will depend heavily on extension of the irrigated area, but much can also be achieved by the breeding of earlier maturing varieties coupled with improvements in fertilizer use and minimum tillage procedures.