Dissertations / Theses on the topic 'Plant amendments'
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1
Sheta, Omar T. "Phytoremediation and rhizosphere manipulation using different amendments." Thesis, University of Glasgow, 2006. http://theses.gla.ac.uk/2147/.
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In two pot experiments using two different crop ryegrass (Lolium perenne) and two flax (Linum usitatissimum) varieties Viola and Elise, ryegrass decreased in the pool of heavy metals compared with bare soil using EDTA as extractant. NH4+ decreased the soil pH, increased EDTA-extractable Zn and increased the Zn uptake. Lime addition increased the pH and depressed Zn uptake. The pool of extractable EDTA was not changed by growing both of the flax varieties. Lime increased EDTA-extractable Cu and Pb significantly, but decreased the Zn, and pH increased in this order NH4+
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Summerville, Kevin M. "Effectiveness of Amendments and Microbial Treatments on Plant Growth in Urban Garden Soils." Youngstown State University / OhioLINK, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=ysu1495712379969062.
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Kitchens, Shane C. "AN INTEGRATED SUBTERRANEAN TERMITE MANAGEMENT SYSTEM COUPLING SOIL AMENDMENTS WITH INSECT REPELLENT PLANT TISSUES." MSSTATE, 2008. http://sun.library.msstate.edu/ETD-db/theses/available/etd-03262008-170913/.
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Currently, soil termiticides are the primary termite defense mechanism used under and around living spaces in the continental United States. While this form of treatment has been effective for many years, the creation of a new, more environmentally friendly termite management system could reduce the amount of termiticides introduced annually into the environment around structures. A natural barrier containing soil amendments and mulches amended with insect-repellent plant tissues discourages termite foraging and directs the termites away from the structure. The proposed integrated management system developed during this project, divides a structure into three zones. Each zone has particular responsibilities to the overall biological durability of the structure. This study concentrates on the inner-detritus zone, which extends 24 (0.61m) from the outer wall of the structure, an area that can harbor potential hazards such as moisture traps, conducive termite food, water and protection sources, and other factors that could put undue biological pressures on the structure. Altering this zone, more specifically the pH of the soil and the mixture of products used as mulch, creates an environment unsuitable for termite foraging. This integration of several termite repelling strategies should obviate or significantly reduce the need for termiticidal soil barriers under and around houses.
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Short, Nicolyn. "Implications of green manure amendments on soil seed bank dynamics." University of Western Australia. School of Earth and Geographical Sciences, 2006. http://theses.library.uwa.edu.au/adt-WU2006.0022.
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[Truncated abstract] Weeds are a major limitation to agricultural and horticultural production and the main method of control is the use of herbicides. In addition to the resulting chemical pollution of the environment, the wide spread and continues use of herbicides have resulted in many weeds developing resistance to commonly used herbicides. This study investigated the potential of using green manures as a cultural method of control of weed invasion in agricultural fields. To understand the general mechanisms involved in the suppression of seed germination in green manure amended soils, seeds of crop species with little or no dormancy requirements were used in certain studies. Lettuce (Lactuca sativa) and cress (Lepidium sativum) seeds were sown to a sandy soil amended with green manures of lupin (Lupinus angustifolius), Brassica juncea, or oats (Avena sativa) to determine if the amendments affected seed germination and/or decay. It was hypothesised that the addition of plant material would increase the microbial activity of the soil thereby increasing seed decay, under laboratory and greenhouse conditions. Initial experiments used lettuce, cress and lupin seeds. Lettuce and cress are commonly used as standard test species for seed viability studies. Subsequent experiments used seeds of annual ryegrass (Lolium rigidum), silver grass (Vulpia bromoides), wild radish (Raphanus raphanistrum) and wild oat (Avena fatua) as these weed species are commonly found throughout agricultural regions in Western Australia. Amending the soil with lupin or Brassica green manure was established as treatments capable of developing environments suppressive to seed germination. Lupin residues as green manure showed the strongest inhibition of seed germination and seed decay. The decay of certain seeds was enhanced with changes to soil microbial activity, dissolved organic carbon and carbon and nitrogen amounts in lupin amended soil. Seeds of weed species were decayed in lupin amended soil, but showed varied degree of decay. Annual ryegrass and silver grass were severely decayed and wild oat and wild radish were less decayed, in lupin amended soil.
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Lucas, Shawn T. "MANAGING SOIL MICROBIAL COMMUNITIES WITH ORGANIC AMENDMENTS TO PROMOTE SOIL AGGREGATE FORMATION AND PLANT HEALTH." UKnowledge, 2013. http://uknowledge.uky.edu/pss_etds/24.
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The effects of managing soil with organic amendments were examined with respect to soil microbial community dynamics, macroaggregate formation, and plant physio-genetic responses. The objective was to examine the possibility of managing soil microbial communities via soil management, such that the microbial community would provide agronomic benefits. In part one of this research, effects of three amendments (hairy vetch residue, manure, compost) on soil chemical and microbial properties were examined relative to formation of large macroaggregates in three different soils. Vetch and manure promoted fungal proliferation (measured via two biomarkers: fatty acid methyl ester 18:2ω6c and ergosterol) and also stimulated the greatest macroaggregate formation. In part two of this research, effects of soil management (same amendments as above, inorganic N fertilization, organic production) on soil chemical and microbial properties were examined relative to the expression of nitrogen assimilation and defense response genes in tomato (Solanum lycopersicum L.). Soil management affected expression of a nitrogen assimilation gene (GS1, glutamine synthetase) and several defense-related genes. The GS1 gene was downregulated with inorganic N fertilization, expression of the pathogenesis-related PR1b gene (which codes for the pathogenesis-related PR1b protein) was increased in plants grown in soil amended with compost, vetch, and N fertilizer, and expression of three other defense-related genes coding for chitinase (ChiB), osmotin (Osm), and β-1,3-glucanase (GluA) were decreased in plants from soil amended with manure and in plants from the organically managed soil. Differential expression of defense-related genes was inversely related to the relative abundance of Gram-negative bacteria. The relative abundance of the 18:1ω7c Gram‑negative bacterial biomarker was greatest in manure treated soil and in organically managed soil (which recieves seasonal manure applications). These treatments also had the lowest expression of ChiB, Osm, and GluA, leading to speculation that manure, through increases in Gram-negative bacteria, may have suppressed populations of soil organisms that induce a defense response in plants, possibly allowing for less-stressed plants. Outcomes of this research may be useful for those interested in developing management strategies for maintaining or improving soil structure as well as those interested in understanding management effects plant physio-genetic responses.
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Awada, Salam Mahmoud. "Amelioration Effects of Calcium Amendments on the Growth of Phaseolus vulgaris L. Under Sodium Stress." DigitalCommons@USU, 1991. https://digitalcommons.usu.edu/etd/3452.
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Two greenhouse experiments were conducted to determine the amelioration effect of Ca salts (CaS04 and CaC12 ) on the growth of snapbeans (Phaseolus vulgaris L.) under sodium stress and to determine the effect of ion speciation on the uptake of Ca, Na, S04, and Cl by snapbeans.
In Experiment 1, the seeds were grown in styrofoam pots, with a growing medium of sand and vermiculite at a volume ratio of 3:1. The treatment solutions were 0 (Hoagland's solution), 20, 40, 60, and 80 mmolc/L NaCl or Na2S04.
Statistical analysis (ANOVA) showed that NaCl treatments depressed the growth of snapbeans more than corresponding Na 2S04 treatments. Also NaCl treatments increased the uptake of Na and Ca as compared to Na2S04treatments. Sodium uptake appeared to be related to the concentrations of complex species rather than to free Na ion, whereas Ca uptake strongly correlated with free Ca2+ concentration.
In Experiment 2, the seeds were grown in a sand growing medium. The treatment solutions were 0 (Hoagland's solution), 15, 30, 45, and 60 mmolc/L NaCl or Na2S04 , combined with CaSO4 • 2H20 or CaCl2 • 2H20 at concentrations of 15 or 30 mmolc/L . In addition, one replicate was planted in PVC cells (with electrodes) in order to monitor the electrical conductivity of the media using the four probe.
The results showed that addition of CaS04 to NaCl or Na2S04 was associated with a better amelioration of Na stress than CaCl2 • Also the presence of CaS04 , with NaCl or Na2S04 , decreased the uptake of Ca and Na ions relative to CaCl2 treatment. Ion speciation data suggested that Na complexation was more important than free ion concentration in affecting Na uptake by the plant, whereas Ca, S04 , and Cl uptake were correlated to free ion concentrations.
With respect to EC, determinations, the four probe was used to monitor salinity during the whole experiment period. Ion speciation data showed that Na2S04 treatments had a lower EC than NaCl at the same molar concentration levels. Also, CaS04 treatments, regardless of the Na salt, had lower EC values than CaCl2 treatments of equal concentration.
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Moonilall, Nall Inshan. "Impact of Amendments on Soil Properties and Agronomic Productivity in Guyana." The Ohio State University, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=osu1430925071.
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Gebhardt, Martha Mary. "Soil Amendment Effects on Degraded Soils and Consequences for Plant Growth and Soil Microbial Communities." Thesis, The University of Arizona, 2015. http://hdl.handle.net/10150/556614.
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Human activities that disrupt soil properties are fundamentally changing ecosystems. Soil degradation decreases microbial abundance and activity, leading to changes in nutrient availability, soil organic matter, and plant growth and establishment. Land use and land cover change are widespread and increasing in semiarid regions of the southwestern US, which results in reductions of native plant and microbial abundance and community diversity. Here we studied the effects of soil degradation and amendments (biochar and woodchips) on microbial activity, soil carbon and nitrogen availability, and plant growth of ten semi-arid plants species native to the southwestern US. Results show that woodchip amendments result in poor overall plant growth, while biochar amended soils promoted plant growth when soil quality was reduced. Additionally, amendments had a strong influence on microbial activity, while the presence and species identity of plants did not. Biochar amended soils led to increases in the potential activities of enzymes involved in the degradation of carbon, nitrogen, and phosphorus rich substrates. Woodchips, caused an increase of potential activity in enzymes involved in the degradation of sugar and proteins. These results show that microbes and plants respond differently to soil treatments and suggest that microbial responses may function as earlier indicators of the success of re-vegetation attempts.
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Winslow, Jonathan W. "Evaluation of Host Resistance and the Utilization of Organic Amendments to Manage Macrophomina Crown Rot of Strawberry in California." DigitalCommons@CalPoly, 2019. https://digitalcommons.calpoly.edu/theses/2075.
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The production of strawberries can be severely limited by soilborne plant pathogens, insects and weeds. Macrophomina phaseolina is a problematic soilborne fungal pathogen in California strawberry production inciting the disease Macrophomina crown rot. When established, the pathogen can cause extensive plant decline and mortality. Host resistance will be a critical tool for managing this disease and guiding breeding programs in the post methyl bromide era. Evaluation of host resistance in strawberry germplasm to M. phaseolina was evaluated through phenotypic assessments of disease incidence. A total of 90 strawberry cultivars and elite selections were included in a replicated field trial conducted in artificially inoculated soils to assess host resistance. Significant differences in levels of resistance and susceptibility were observed among genotypes tested in this trial. The five most resistant strawberry genotypes from highest to lowest in percent plant mortality were: UC-R, UC-G, UC-V, Manresa, and Osceola. The five most susceptible strawberry genotypes with the highest percent mortality in ranking order from highest to lowest were: UC-J, Ruby June, Festival, UC-Y, and UC-A. Of the genotypes tested in this trial UC-V, Manresa and Osceola could be characterized as highly resistant, but no complete resistance was observed.
An additional study was conducted to correlate host symptom expression with the extent of pathogen colonization in different strawberry tissues, and to determine if resistant germplasm can contribute to secondary inoculum production in the field. An established qPCR method was utilized to quantify M. phaseolina colonization of strawberry tissues. There were significant effects for cultivar (P < 0.0001) as well as a significant two-way interaction of cultivar x sample time (P= 0.0083) on the concentration of M. phaseolina DNA detected in strawberry tissues. Expression of the resistant phenotype in strawberry cultivars was associated with limited plant colonization by M. phaseolina. The extent of colonization of a specific cultivar by M. phaseolina was dependent on the sample time after inoculation with the pathogen. In addition, the roots and crowns of a specific strawberry cultivar were equally colonized on a per plant tissue weight basis, but this provides only speculation into the mechanisms conferring host resistance.
A third study was conducted to integrate host resistance of strawberry genotypes with the use of organic amendments in effort to mutually enhance the efficacy of each factor for the control of Macrophomina crown rot. Artificially inoculated potting substrate was amended with Brassica juncea mustard seed meal at a rate of 4.94 tons ha-1(MSM), and anaerobic soil disinfestation utilizing rice bran at a rate of 22.24 tons ha-1 (ASD) were compared to a non-amended (UTC) and steam controls. The soil assay indicated that the ASD and steam treatments were able to reduce the CFU g-1 potting substrate of M. phaseolina by 99.7-100%. In addition, there were significant effects of soil treatment on the fresh biomass of weed seedlings recovered from the potting substrate. However, disease severity and host colonization of multiple strawberry cultivars by M. phaseolina was not reduced when grown in the treated potting substrate. The effect of strawberry cultivar on the extent of pathogen colonization was highly significant (P < 0.0001), in which cultivars characterized as resistant from phenotypic screenings possessed lower concentrations of M. phaseolina DNA. The suppression of M. phaseolina in response to organic amendments was limited but this study supports findings from previous experiments that genotype specific host resistance minimizes host colonization and reduces the production of secondary inoculum.
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Nilsson, K. Sofia. "Modelling soil organic matter turnover /." Uppsala : Dept. of Ecology and Environmental Research, Swedish Univ. of Agricultural Sciences, 2004. http://epsilon.slu.se/s326.pdf.
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Wells, Daniel Evans Sibley Jeffrey Lynn. "Evaluation of spent tea grinds as an alternative horticultural substrate component." Auburn, Ala, 2008. http://hdl.handle.net/10415/1472.
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Smit, Rosanne. "Nematodes in British Columbia vineyards : indicators of soil food web responses to compost amendments and impacts of the plant-parasite, Mesocriconema xenoplax." Thesis, University of British Columbia, 2009. http://hdl.handle.net/2429/13695.
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Vineyard owners in the Okanagan valley of BC are increasingly reporting under-performing blocks of grapevines. Until recently, plant parasitic nematodes were overlooked as factors contributing to decreased vigor in Okanagan vineyards. Analysis of soil from several underperforming vineyards revealed the presence of several species of plant parasitic nematodes, including ring nematodes (Mesocriconema xenoplax), that could be causing economically important damage to grapevines.
M. xenoplax has been associated with grapevines in most major grape-growing regions of the world. Research conducted in field microplots in Oregon and California indicate that M. xenoplax can cause significant reductions in grapevine growth. The impact of plant parasitic nematodes and M. xenoplax in particular on grapevines under British Columbia growing conditions has not yet been determined.
The research objectives were to determine if M. xenoplax has detrimental effects on growth of self-rooted vines and three rootstocks growing in sandy soils typical of the most south Okanagan vineyards and also to determine if application of compost to the root zone of mature grapevines decreases M. xenoplax population densities and enhances nematode community indicators of soil food web enrichment and structure.
After two growing seasons of microplot trials, M. xenoplax decreased trunk diameters and pruning weights of self-rooted vines (Merlot) but did not decrease growth parameters of any of the rootstocks evaluated (Riparia Gloire, 44-53M, 3309C).
Composted layer manure was surface-applied to the root zone of established vines in two commercial vineyards for three consecutive years at modest rates. At the first sample date, six months after the last compost application, all nematode trophic groups were more abundant in the compost-amended plots than in the fertilizer-treated plots indicating fluxes of nutrients through the soil food web. The enhancement of the soil food web did not appear to persist through the second growing season.
Results from this research show that compost applications are beneficial to free-living nematode communities in sandy soils of the Okanagan, at least in the short term, and may buffer root feeding damage by plant parasitic nematode populations, especially M. xenoplax, which is indeed detrimental to grapevines.
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Walker, Bradley James. "The feasibility of incorporating various amendments into Copper Cliff slag to create a slag-based plant growth medium for the purpose of revegetation." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2001. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/MQ61305.pdf.
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Amisi, Karen Janila. "Strategies for managing weeds in a wheat, red clover, vegetable crop rotation transitioning to organic production." The Ohio State University, 2005. http://rave.ohiolink.edu/etdc/view?acc_num=osu1104246323.
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Laudick, Julia Ann. "Microbial Biostimulants in Organic Farming Systems: Patterns of Current Use and an Investigation of Their Efficacy in Different Soil Environments." The Ohio State University, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=osu1483689529339271.
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Lu, Wenliang Sibley Jeffrey Lynn. "Utilization of municipal solid waste compost in horticulture." Auburn, Ala., 2008. http://repo.lib.auburn.edu/EtdRoot/2008/SPRING/Horticulture/Dissertation/Lu_Wenliang_10.pdf.
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Soratto, Rogério Peres [UNESP]. "Aplicação de calcário e gesso em superfície na implantação do sistema de plantio direto." Universidade Estadual Paulista (UNESP), 2005. http://hdl.handle.net/11449/100003.
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soratto_rp_dr_botfca.pdf: 792481 bytes, checksum: 32d9518363b0fae5fab589ed74ffbe8c (MD5)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
Existe interesse na busca de alternativas para a implantação do sistema de plantio direto em áreas anteriormente cultivadas no sistema convencional de preparo do solo ou sob pastagens, sem a incorporação prévia do calcário, realizando-se a calagem superficialmente desde o estabelecimento do sistema, desde que não haja impedimento físico ao crescimento radicular. Nesse sentido, o gesso agrícola, por ser mais solúvel e apresentar relativa mobilidade no solo, é apontado como alternativa para correção das camadas subsuperficiais do solo em curto prazo, podendo ser utilizado como um produto complementar ao calcário. Dessa forma, o trabalho objetivou avaliar a influência da aplicação superficial de calcário e gesso, na implantação do sistema de plantio direto, sobre as características químicas do solo, o teor de cátions solúveis na parte aérea das culturas, o crescimento radicular, a nutrição e produtividade de culturas anuais, em região de inverno seco. O experimento foi conduzido nos anos agrícolas de 2002/2003 e 2003/2004, na Fazenda Experimental Lageado, localizada no município de Botucatu (SP), em um Latossolo Vermelho distroférrico, anteriormente conduzido no sistema convencional de preparo do solo. O delineamento experimental foi em blocos casualizados com parcelas subdivididas e quatro repetições. As parcelas foram constituídas por quatro doses de calcário dolomítico (0, 1.100, 2.700 e 4.300 kg ha-1), com PRNT = 71,2%, visando elevar a saturação por bases para 50%, 70% e 90%, respectivamente. As subparcelas foram constituídas pela ausência e aplicação de 2.100 kg ha-1 de gesso agrícola (6 x teor de argila em g kg-1, na camada de 0,20-0,40 m de profundidade). Para as culturas de verão foi utilizado o esquema de parcelas subsubdivididas, sendo as subsubparcelas constituídas por dois cultivares de arroz de terras altas...
There is great interest to search alternatives to establish the no-tillage system in fields previously cultivated on conventional tillage or on pasture, with no lime previous incorporation, using superficial liming since the beginning of system, if don't have physical impediment to root growth. Thus, the phosphogypsum, that is more soluble and with high mobility, has been an alternative to correct the subsuperficial soil layer, in a short time, and can be used as a lime complementary product. Therefore, the objective of this work was to evaluate the effects of lime and phosphogypsum surface application during the establishment of no-tillage system, on the soil chemical characteristics, on the content of water-soluble cations, in the crop shoot, on the root growth, on the nutrition and yield of annual crops, in a dry winter region. The experiment was carried out during the agricultural years of 2002/03 and 2003/2004, in an experimental area located in Botucatu County, São Paulo State, Brazil (48º 23' W and 22º 1' S) on a Haplorthox, before used with conventional tillage system. A randomized complete block design, in split-plot scheme, and four replications was used. The plots were composed by four dolomite limestone levels (0; 1,100; 2,700; and 4,300 kg ha-1), with Neutralization Power = 84.3% and Reactivity = 84.5%, aiming raise the base saturation to 50%, 70%, and 90%, respectively. The subplots were composed by without and with phosphogypsum application (2,100 kg ha-1 = 6 x clay content (g kg-1) in 0.20-0.40 m depth layer). For the summer crops a split-split-plot scheme were used. The subsubplots were constituted by two upland rice cultivars ('Caiapó' and 'IAC 202'), on agricultural year of 2002/03, and two common bean cultivars ('Carioca' and 'Pérola'), on agricultural year of 2003/2004. In the winter season of 2003 and 2004, the black oat was grown in the area... (Complete abstract click electronic access below)
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Heckman, John Richard. "Restoration of Degraded Land: A comparison of Structural and Functional Measurements of Recovery." Diss., Connect to this title online, 1997. http://scholar.lib.vt.edu/theses/available/etd-1416152839711171/.
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Zhou, Shuang. "EVALUATING SOIL PHYSICAL AND CHEMICAL PROPERTIES FOLLOWING ADDITION OF NON-COMPOSTED SPENT COFFEE AND TEA FOR ATHLETIC FIELDS." UKnowledge, 2017. https://uknowledge.uky.edu/pss_etds/96.
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Physical and chemical properties of non-composted spent coffee (CF) and tea (T) suggest they may have applications as soil amendments for improving poor soils. Studies were conducted to determine 1) the effect of amendments on grass growth and soil properties, 2) the effect of incorporation versus surface application of amendments on soil properties, and 3) the effect of amendment application frequency on grass growth and soil properties. In the first study, amendments were mixed with sand and planted to bermudagrass. Treatments included CF, T, and peat moss (PM) mixed with sand, and 100% sand as a control. In the second study, amendments were topdressed onto a sand base with different timings. Pots were either aerified or not. Treatments included T, CF, PM, and a control. Nutrient contents and soil CEC and OM under CF and T treatments were equivalent to or greater than PM treatments. Tea showed comparable grass cover to the PM treatment, while CF showed an inhibitory effect to grass growth in the first year of the study. Aerification showed no benefit. Additionally, a field study was conducted to evaluate CF and T on surface hardness, VWC, and quality after trafficking. Differences were not observed among treatments.
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Teklay, Tesfay. "Organic inputs from agroforestry trees on farms for improving soil quality and crop productivity in Ethiopia /." Umeå : Dept. of Forest Ecology, Swedish University of Agricultural Sciences, 2005. http://epsilon.slu.se/2005122.pdf.
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Soratto, Rogério Peres 1976. "Aplicação de calcário e gesso em superfície na implantação do sistema de plantio direto /." Botucatu : [s.n.], 2005. http://hdl.handle.net/11449/100003.
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Orientador: Carlos Alexandre Costa CrusciolBanca: Ciro Antonio Rosolem
Banca: Godofredo Cesar Vitti
Banca: Domingos FornasieriFilho
Banca: Luis Reynaldo F. Alleoni
Resumo: Existe interesse na busca de alternativas para a implantação do sistema de plantio direto em áreas anteriormente cultivadas no sistema convencional de preparo do solo ou sob pastagens, sem a incorporação prévia do calcário, realizando-se a calagem superficialmente desde o estabelecimento do sistema, desde que não haja impedimento físico ao crescimento radicular. Nesse sentido, o gesso agrícola, por ser mais solúvel e apresentar relativa mobilidade no solo, é apontado como alternativa para correção das camadas subsuperficiais do solo em curto prazo, podendo ser utilizado como um produto complementar ao calcário. Dessa forma, o trabalho objetivou avaliar a influência da aplicação superficial de calcário e gesso, na implantação do sistema de plantio direto, sobre as características químicas do solo, o teor de cátions solúveis na parte aérea das culturas, o crescimento radicular, a nutrição e produtividade de culturas anuais, em região de inverno seco. O experimento foi conduzido nos anos agrícolas de 2002/2003 e 2003/2004, na Fazenda Experimental Lageado, localizada no município de Botucatu (SP), em um Latossolo Vermelho distroférrico, anteriormente conduzido no sistema convencional de preparo do solo. O delineamento experimental foi em blocos casualizados com parcelas subdivididas e quatro repetições. As parcelas foram constituídas por quatro doses de calcário dolomítico (0, 1.100, 2.700 e 4.300 kg ha-1), com PRNT = 71,2%, visando elevar a saturação por bases para 50%, 70% e 90%, respectivamente. As subparcelas foram constituídas pela ausência e aplicação de 2.100 kg ha-1 de gesso agrícola (6 x teor de argila em g kg-1, na camada de 0,20-0,40 m de profundidade). Para as culturas de verão foi utilizado o esquema de parcelas subsubdivididas, sendo as subsubparcelas constituídas por dois cultivares de arroz de terras altas... (Resumo completo, clicar acesso eletrônico abaixo)
Abstract: There is great interest to search alternatives to establish the no-tillage system in fields previously cultivated on conventional tillage or on pasture, with no lime previous incorporation, using superficial liming since the beginning of system, if don't have physical impediment to root growth. Thus, the phosphogypsum, that is more soluble and with high mobility, has been an alternative to correct the subsuperficial soil layer, in a short time, and can be used as a lime complementary product. Therefore, the objective of this work was to evaluate the effects of lime and phosphogypsum surface application during the establishment of no-tillage system, on the soil chemical characteristics, on the content of water-soluble cations, in the crop shoot, on the root growth, on the nutrition and yield of annual crops, in a dry winter region. The experiment was carried out during the agricultural years of 2002/03 and 2003/2004, in an experimental area located in Botucatu County, São Paulo State, Brazil (48º 23' W and 22º 1' S) on a Haplorthox, before used with conventional tillage system. A randomized complete block design, in split-plot scheme, and four replications was used. The plots were composed by four dolomite limestone levels (0; 1,100; 2,700; and 4,300 kg ha-1), with Neutralization Power = 84.3% and Reactivity = 84.5%, aiming raise the base saturation to 50%, 70%, and 90%, respectively. The subplots were composed by without and with phosphogypsum application (2,100 kg ha-1 = 6 x clay content (g kg-1) in 0.20-0.40 m depth layer). For the summer crops a split-split-plot scheme were used. The subsubplots were constituted by two upland rice cultivars ('Caiapó' and 'IAC 202'), on agricultural year of 2002/03, and two common bean cultivars ('Carioca' and 'Pérola'), on agricultural year of 2003/2004. In the winter season of 2003 and 2004, the black oat was grown in the area... (Complete abstract click electronic access below)
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Banaitis, Michael R. "Biogeochemical Response of a Northeastern Forest Ecosystem to Biosolids Amendments." Fogler Library, University of Maine, 2007. http://www.library.umaine.edu/theses/pdf/BanaitisMR2007.pdf.
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Malosso, Elaine. "Effects of plant amendment on microbial community structure and fungal biomass in Antarctic soils." Thesis, University of Newcastle Upon Tyne, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.289240.
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Tomlinson, Ian Rory. "The amendment of acid soil with an ettringitic waste and its effects on plant growth." Master's thesis, University of Cape Town, 1995. http://hdl.handle.net/11427/21334.
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Bibliography: pages 63-68.Associated with ESKOM's ash water beneficiation programme is the precipitation of an ettringitic waste from highly alkaline, saline water. The waste is dominated by ettringite (CauAJ4(OH)24(S04) 6.52H20) with calcite (CaC03) as a minor phase (17.7% for the sample used in this study). Apart from the presence of calcite, the ettringite itself is alkaline due to the presence of OH ions. Following a submission that the waste had potential as an ameliorant of acid soil, research into this possibility was initiated. Following the determination of a calcium carbonate equivalent (HCl-CCE) value of 78% using the HCl back titration method of Horwitz (1980), an incubation experiment was initiated using three acid soils of contrasting characteristics: a so-called Silvermine sand, Kranskop A and Kranskop B soils. The effects on soil acidity of ettringitic waste were compared with analytical grade calcite. Soils (50g samples) were incubated with the two alkaline amendments for two weeks, following which pH(KCl), pH(H20) and KCl-extractable acidity were determined. Ettringitic waste led to apparently lower levels of acidity neutralization for corresponding treatments set on an HCl-CCE basis. This difference was minimized with the highly buffered, sesquioxide and organic-rich Kranskop A soil which could be attributed to the greater reactivity of the ettringitic waste with organically-complexed acidity together with the "self-liming" effect of so4 in sesquioxide-rich soils (sensu Reeve & Sumner, 1972). The waste showed progressively less neutralization with Kranskop B and Silvermine soils apparently in response to a decline in buffering capacity of these soils.
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Lange, Ian. "Investigating the effects of the 1990 Clean Air Act Amendments on inputs to coal-fired power plants /." Thesis, Connect to this title online; UW restricted, 2005. http://hdl.handle.net/1773/7421.
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Hurtado, Cervera Carlos. "Fate and effects of waterborne contaminants of emerging concern in the soil-plant system : impact of biochar soil amendment to mitigate their plant uptake." Doctoral thesis, Universitat Politècnica de Catalunya, 2017. http://hdl.handle.net/10803/458444.
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Water scarcity is an issue of global concern due to the increase of the population and the climate change, which both increase the water demand. Many arid and semiarid countries are facing high water stress and the use of reclaimed water becomes a valuable resource. Many countries' economy is based on the agro-food sector, with amounts ca. the 70% of water demand. For this reason, reclaimed water represents an important component of wise water management.
Wastewater treatment plants (WWTP) are designed to remove efficiently some biodegradable compounds, however, they are not able to remove a number of recalcitrant organic coñtamina0nts known as chemical oxygen demand (COD). There are many sources of water pollution, and contaminants of emerging concern (CECs) including many compounds that they are not legislated and recently some effects to the environment have been observed. For example, pharmaceuticals, personal care products, flame retardants, microplastics, etc.
Consequently, plants are exposed to a huge number of chemical contaminants that are present not only in water, but also in air or soil. For this reason, it is important to understand the dynamics involved in the plant uptake of these CECs and more specifically in crops.
In this Thesis, the uptake of some CECs, chosen by their occurrence in the environment and their physical-chemical properties, has been assessed. To elucidate the factors that are involved in the uptake of these contaminants, three different experiments were performed in a greenhouse.
Therefore, this Thesis is divided in the three experiments. In the first one, the plant uptake of some CECs with a perlite:sand mixture and its modelling were assessed. Moreover, a mass balance was performed to evaluate the persistence of the CECs in the substrate. Then, by inverse modelling, the half-lives of CECs in the soil-plant system were estimated.
In the second experiment, most of the CECs that were added in the irrigation water were taken up by lettuce. Hence, in this experiment, biochar, which is a soil improver, was assessed as a soil amendment to mitigate the uptake of these CECs in lettuce. To confirm this hypothesis, different biochar amendments were performed (O, 2.5 and 5% w/w biochar) to an agricultural soil from the Llobregat's Delta. Finally, it could be observed that the addition of biochar, reduced the concentration of CECs in lettuces.
Since these two experiments demonstrated that CECs can be uptaken by crops and translocated to edible parts, and it well known that plants can metabolize xenobiotics through transformation, conjugation and sequestration steps, in the third experiment, an enzymatic digestion was performed to determine the conjugated CECs fraction. Interestingly, the conjugated fraction accounted up to more than 80%, which should be taken into account in risk assessment studies.
Finally, in the same experiment, some effects of CECs to lettuce were elucidated. Visual differences between non-exposed and exposed lettuce were observed. For this reason, a metabolomic approach was applied to correlate the presence of CECs with the changes in the metabolome and the changes in chlorophyll content and plant morphology.L'escassetat d'aigua és un tema de gran preocupació degut a l'augment de la població i el canvi climàtic, que tan que s’elevi la demanda d'aigua. Molts països amb un clima àrid o semiàrid s'enfronten a un elevat estrès hídric. En aquest context, l'ús d'aigua regenerada es converteix en una practica clau. L'economia de molts passos es basa en el sector agroalimentari, que requereix grans quantitats d'aigua pel seu desenvolupament. Per aquesta raó, l'aigua regenerada representa un component important en la gestió intel·ligent de l'aigua. Les estacions depuradores d'aigües residuals (EDAR) estan dissenyades per eliminar de manera eficient alguns compostos biodegradables. Tot i així, no són capaces d'eliminar una sèrie de contaminants orgànics. Hi ha molts tipus de contaminació en l'aigua i els contaminants emergent (CECs) inclouen molts compostos que no estan legislats i recentment s'han observat alguns efectes en el medi ambient. Alguns exemples de CECs són fàrmacs, productes de cura personal, retardants de flama, microplàstics, etc. En conseqüència, les plantes estan exposades a un gran nombre de contaminants que es troben presents no només en aigua, sinó també en l’aire o el sol. Per aquest motiu, és important entendre la dinàmica implicada en l'absorció d’aquests contaminants en plantes i cercar estratègies per mitigar aquesta possible absorció. Aquest treball de recerca té com a objectiu estudiar l'absorció de diversos CECs en enciams, que han estat seleccionats perla seva presencia en el medi ambient i les seves propietats fisicoquímiques. Per dilucidar els paràmetres que estan implicats en l’absorció d'aquests contaminants en enciams, tres experiments diferents s’han dut a terme en l’estació experimental Agròpolis pertanyent a la UPC. Per tant, aquesta Tesi es pot separar en els 3 experiments duts a terme. En el primer experiment, es va avaluar l'absorció d'alguns CECs en enciams emprant un substrat format per una mescla de sorra i perlita. L’experiment va dilucidar que la majoria deis CECs van ser absorbits pels enciams i translocats a les parts aèries deis enciams. D'altra banda, un balanç;: de masses es va realitzar per avaluar la persistència deis CECs en el substrat. Després, mitjançant models d’incorporació de contaminants en plantes, es van estimar les vides mitjanes deis CEC en el sistema sol-planta. En un següent experiment, l’ús de biocarbó (biochar) es va proposar com una esmena del sol per reduir l'absorció d'aquests CECs als enciams. Per dur confirmar aquesta hipòtesi, es van afegir diferents percentatges de biochar (O, 2,5 i 5% de biochar) en un sol agrícola de la zona agrícola del Delta del Llobregat. Finalment, es va poder observar que l’addició de biochar reduí la concentració deis CECs en els enciams. Aquests dos primers experiments van ser útils per evidenciar que aquests compostos es poden absorbir fàcilment perles plantes i arribar a les parts que comestibles. No obstant, en altres estudis s’ha demostrat que les plantes són capaços de metabolitzar xenobiòtics a través de tres passos: transformació, conjugació i segrest deis CECs. Per aquest motiu, es va realitzar una digestió enzimàtica per determinar la fracció de CECs que podrien ser conjugats. Curiosament i segons el contaminant, la fracció conjugada va representar més del 80% del compost parental, evidenciant que la fracció conjugada s'ha de tenir en compte en els estudis d'avaluació de risc humà. Finalment, en aquest mateix experiment, es varen observar diferencies morfològiques entre els enciams exposats a un còctel de CECs i els no exposats als contaminants. A més, la determinació de clorofil·les també va evidenciar diferencies entre tractaments. Per aquesta raó, es van extreure els metabòlits secundaris deis enciams emprant un enfocament metabolòmic juntament amb tècniques quimiomètriques per correlacionar la presencia d’aquests contaminants amb els canvis morfològics i en el contingut de clorofil·la i dels metabòlits secundaris
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Harper, John, Jack Watson, and Tom Doerge. "The Effect of Various Soil Amendments on the Yield of Alfalfa and Soil Infiltration Rates." College of Agriculture, University of Arizona (Tucson, AZ), 1986. http://hdl.handle.net/10150/200479.
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Henderson, Jennifer Jacobs. "Hayden Covington, the Jehovah's Witnesses and their plan to expand First Amendment freedoms /." Thesis, Connect to this title online; UW restricted, 2002. http://hdl.handle.net/1773/6183.
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Schuch, Ursula K., Jack Kelly, and Frank Stryker. "Effect of Planting Hole Size and Amendments on Growth and Establishment of Acacia farnesiana." College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 2004. http://hdl.handle.net/10150/216554.
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The objective of this project was to determine whether the size of planting holes and the addition of organic material in the backfill is beneficial for plant establishment and growth during the early years. Acacia farnesiana were transplanted from containers into a permanent landscape using four methods: large planting hole with or without amendments or a small planting hole with or without amendments. The study was repeated on two sites. Three years following transplanting, plant growth such as height and caliper were not affected by the planting hole size or amendments, but differed significantly between sites. Plants that received more irrigation and were planted in a less rocky soil had greater caliper and were taller than those supplied with less irrigation and planted on a more rocky soil. Visual observations one and three years after transplanting indicate that trees that were amended with compost in the backfill had the highest incidence of leaning trunks and sinking crowns (20% of trees in study or 37% of those receiving amendments) while of those trees that were not amended only one tree (3%) was leaning three years after transplanting. Hole size at transplanting had no significant effect on leaning or sinking three years after transplanting. These results confirm earlier research across the country that 33% to 50% organic amendment in backfill compared to native soil at transplanting is not beneficial for native trees, but increases the risk of leaning or sinking.
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Carmichael, Travis Rex. "Landscape establishment and irrigation management of ornamental plants grown in eastern redcedar substrate." Thesis, Kansas State University, 2013. http://hdl.handle.net/2097/15661.
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Master of ScienceDepartment of Horticulture, Forestry, and Recreation Resources
Cheryl R. Boyer
Pine bark (PB) has been the principal component of nursery crop substrates in the United States for more than 60 years. Substrate material used for the purpose of growing ornamental plants in the Great Plains is generally shipped a great distance, primarily from the Southeastern U.S., due to a lack of pine plantations in this region. Eastern redcedar (Juniperus virginiana L.; ERC), an aggressively weedy tree species, has been identified as a possible alternative to PB for nursery substrates. The objective of this thesis was to evaluate the establishment of Miscanthus sinensis N.J. ‘Little Kitten’ (dwarf maiden grass), Rosa (L.) ‘Radtkopink’ (Knockout® rose), Ilex glabra (L.) A. Gray ‘Compacta’ (holly), Ulmus parvifolia Jacq. ‘Emer II’ (Allee® lacebark elm), Sedum telphium L. ‘Autumn Joy’ (sedum), Hosta Tratt. ‘Sum and Substance’ (hosta), and Hemerocallis L. ‘Charles Johnston’ (daylily) in three substrate mixes. These substrate mixes consisted of 80% PB: 20% sand, 80% ERC: 20% sand, and 40% PB: 40% ERC: 20% sand. At the end of the production phase differences in growth were observed in maiden grass, holly, lacebark elm, and sedum. At the end of the landscape establishment phase, no differences in growth were observed in any species except holly and hosta. To attempt to overcome the sub-optimal physical properties of ERC (high air space and low container capacity), cyclic irrigation was used to evaluate growth of Sedum spectabile Boreau ‘Autumn Fire’ (sedum), Rudbeckia fulgida Aiton ‘Goldstrum’ (black-eyed susan), and Hibiscus moscheutos L. ‘Luna White’ (hibiscus) in the same 3 substrates. The objective of this study was to evaluate the affect of irrigation frequency (1x, 2x, 3x, or 6x per day) and substrate ERC content on plant growth. Sedum had the greatest growth index (GI) shoot dry weight in PB and when irrigated 1x and 2x per day had the greatest root dry weight regardless of substrate. Irrigation frequency had no significant difference for GI and shoot dry weight Black-eyed susan had the greatest GI and shoot dry weight when grown in PB. Irrigation frequency only had an impact on shoot dry weight of black-eyed susan; plants irrigated 1x, 2x, and 3x per day had the greatest growth. Hibiscus had greatest growth in PB: ERC mix. Irrigation frequency had no impact on growth of hibiscus. Cyclic irrigation does not overcome low water holding capacities in these three species. Overall, ERC can be used as a partial replacement to PB (up to 50%). However, further research evaluating effects of different fertility regimes on ERC substrate is warranted.
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Kim, Tae-Kyung. "Dynamic analysis of sulfur dioxide monthly emissions in U.S. power plants." Columbus, Ohio : Ohio State University, 2004. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1086195964.
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Thesis (Ph. D.)--Ohio State University, 2004.Title from first page of PDF file. Document formatted into pages; contains xviii, 218 p.; also includes graphics. Includes abstract and vita. Advisor: Jean Michael Guldmann, City and Regional Planning Graduate Program. Includes bibliographical references (p. 130-133).
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Khosa, Mbokota Candy. "An investigation into the potential of crude and partially separated material of selected non-crop plant species as control agents of root-knot nematodes (Meloidogyne incognita) in tomato / Mbokota Candy Khosa." Thesis, North-West University, 2012. http://hdl.handle.net/10394/8705.
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Plant-parasitic nematodes (PPN) are a serious problem in vegetable production and can
cause severe damage to several crops. In rural, low-input farming nematode damage is
much higher and yields can be completely destroyed. Some Commercial nematicides have
been withdrawn from the market due to health and environment concerns. These need to
be replaced by alternative nematode control strategies of which soil amendments is one
alternative. Nine non-crop plant species used in various forms in traditional healing, viz.
Cassia abbreviata, Cissus cactiformis, Euphorbia ingens, Ipomoea kituiensis, Maerua
angolensis, Senna petersiana, Synadenium cupulare, Tabernaemontana elegans and Urginea
sanguinea were screened under glasshouse conditions for their effect on the plant-parasitic
nematode (PPN) (Meloidogyne incognita) on tomato. Subsequent assessments in microplots
and in the field supported the glasshouse results in terms of suppression of root-knot
nematode numbers with crudely milled soil amendments of C. cactiformis, M. angolensis
and T. elegans. Tomato growth responses in these trials showed a tendency of phytotoxic
effects after treatment of soil with crude leaf meal of E. ingens and S. cupulare. In the
microplot study, the overall soil-amendment treatment effect was greater than that of three
soil types on the performance of the tomato, although soil type might have had an effect on
nematode suppression. Due to lack of correspondence between tomato leaf nutrient
contents and the nutrient contents of the soil amendments it is suggested that these noncrop
materials had negligible soil fertilization effects.
In vitro bioassay studies confirmed that extracts of varying polarity of both plant products
M. angolensis and T. elegans might be toxic to J2 stages of the root-knot nematode M.
incognita. All extracts tested of M. angolensis caused immobility of J2, whereas only three
extracts of T. elegans affected mobility of J2 adversely. Duration to 50 % effect, as well as
extract concentration to cause immobility of the J2 varied but where movement ceased the
J2 did not recover for up to 98 hours.
This study has demonstrated the potential of locally available botanical materials for use as
amendments in plant-parasitic nematode management and tomato growth and productivity
improvement. This would particularly be true for small-scale application in subsistence agriculture. It is believed that these amendments could be used as control measures in
integrated nematode control strategies. Their potential use could be adopted by small-scale
farming communities, domestic gardeners and commercial farmers in the Mpumalanga,
Limpopo and Kwazulu/Natal Provinces of South Africa where the relevant materials are
available in useful quantities. Over-exploitation of natural resources should be avoided at all
cost, however.Thesis (PhD (Environmental Sciences))--North-West University, Potchefstroom Campus, 2013
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Stroehlein, Jack, Tom Doerge, and Lee Clark. "The Effect of Various Soil Amendments on the Yield of Barley When Grown on a Sodium-affected Soil." College of Agriculture, University of Arizona (Tucson, AZ), 1985. http://hdl.handle.net/10150/200512.
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Harper, John, Jack Watson, and Tom Doerge. "The Effect of Gypsum and Sulfuric Acid Soil Amendments on the Yield of Alfalfa and Soil Infiltration Rates: A Progress Report." College of Agriculture, University of Arizona (Tucson, AZ), 1987. http://hdl.handle.net/10150/203795.
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El, Mghadmi Z. Y. "Effect of environmental stresses and growing medium amendment with 'Zander' on growth of Acacia saligna under saline conditions." Thesis, Coventry University, 2011. http://curve.coventry.ac.uk/open/items/5727ee90-f827-485e-93d9-94a9b5456f43/1.
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In Libya salinization of land and ground water is a key problem. A. saligna is one species that offers potential for growth under these conditions. Experiments were undertaken to accelerate the germination of Acacia seeds, and various pre-treatment methods were assayed. Boiling water treatment, mechanical scarification and acid improved germination and germination rate. Sowing A. saligna seeds at 30 mm depth gave greatest seedling growth from large and medium seeds whereas 20 mm was more suitable for small seeds. This study aimed to improve the establishment of Acacia saligna irrigated with saline water, plants were grown for seven weeks under greenhouse or field conditions in (Libya) either sand or soil salinized with varying applications of NaCl. Irrigation with NaCl significantly decreased plant survival and growth and concentration of Ca, Na, K, Fe and P ions in plants with 0.5 M or 1.0 M NaCl. The experiments were repeated using a naturally occurring soil amendment called ‘Zander’. Seeds of A. saligna were grown for seven weeks in both greenhouse and field trials as before but with the addition of Zander and NaCl. Zander improved plant survival and growth with salinity and increased the elements in plants (Ca, Na, K, Fe and P). Field experiments were conducted to assess the effects of saline irrigation with 1.0 M NaCl and extra water added to 0% or 10% Zander on survival and growth, consequently, seedling growth significantly decreased with increase in soil salinity. Survival and growth increased with increase in extra water. The additional irrigation water caused an increase in the uptake of Ca++ and increased the Ca++/Na+ and K+/Na+ ratio. Zander did not appear to reduce net uptake of Na+ and its transport to shoot tissues. Mg++, P, K+ and Ca++ content significantly decreased in plants in response to salinity. Possible mechanisms to avoid Na+ toxicity in A. saligna in response to salinity included increasing the supply of Ca++. Extra Ca++ applied into the medium with and without salt increased survival and growth even in the absence of Zander. Calcium increased uptake of Ca++ and increased Ca++/Na+ and K+/Na+ ratio.
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Bryan, Donita Lynn. "Influence of planting depth on landscape establishment of container-grown trees." [College Station, Tex. : Texas A&M University, 2008. http://hdl.handle.net/1969.1/ETD-TAMU-3179.
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Gudichuttu, Vindhya. "Phytostabilization of multi-metal contaminated mine waste materials: long-term monitoring of influence of soil amendments on soil properties, plants, and biota and the avoidance response of earthworms." Thesis, Kansas State University, 2013. http://hdl.handle.net/2097/16989.
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Master of ScienceDepartment of Agronomy
Ganga M. Hettiarachchi
Mine waste materials from the Tri-State mining region in Kansas, Missouri, and Oklahoma pose environmental hazards. The area is contaminated with trace elements, such as Pb, Zn and Cd, which are transported to surrounding areas through water, wind erosion, and runoff. Phytostabilization or establishing healthy vegetative cover could be used to reduce or control these contaminated materials from further spreading with wind and water. However, further research is needed to monitor the long-term sustainability and assess if high applications of compost amendments could help to facilitate soil reclamation. The overall focus of this thesis was to monitor long-term effects of compost or lime additions at two different rates, with or without other soil amendments, on soil properties, plants, and soil biota. We used the earthworm avoidance test as a screening tool for testing effects of soil amendments on ecotoxicity. In the first field study, pelletized manure compost additions of 448 Mg ha⁻¹ significantly decreased the bioavailable Pb, Zn, and Cd while increasing plant nutrients, vegetative cover, and plant biomass as compared to the contaminated control and the low addition of compost (224 Mg ha⁻¹) over 2.5 years. Plant tissue metal concentrations with compost addition did not show any phytotoxicity in this study. Lime additions did not show any significant effect on any of the measurements. Results from the first study suggest that one time addition of large quantities of compost at 224 to 448 Mg ha⁻¹ can support establishing and maintaining healthy vegetative cover at least for a 2.5 year period. In the second field study, long-term monitoring of the effectiveness of the amendments was studied. Compost was applied at two different rates (45 or 269 Mg ha⁻¹) in 2006. Various chemical properties, microbial activities, and vegetative growth or plant biomass were measured approximately for 4.5 years to evaluate long-term changes in soil quality and sustainability of phytostabilization efforts, when combined or assisted with soil amendments to improve the quality of trace element-contaminated mine waste materials. Plants grown with compost additions of 269 Mg ha⁻¹ showed higher nutrients, biomass, and enzyme activities as compared to plants grown on the contaminated control and with the low addition of compost (45 Mg ha⁻¹) over 4.5 years. Decrease in plant biomass and enzyme activities seen in the high compost treatments by the end of the study period suggested that long-term sustainability of these efforts may require repeated addition of soil amendments every 4 to 5 years. Additionally, a laboratory study was conducted to assess the long-term effects of treatments used in the second field study on ecotoxicity using the avoidance behavior responses of the earthworm Eisenia fetida. There was no mortality of earthworms after a 48 h exposure period of any of these treated and untreated mine waste materials. Avoidance was clear for the contaminated control and the low compost treatment (45 Mg ha⁻¹). Moreover, the contaminated control did show habitat limitation (< 20% of earthworms was found in test soil). Current research studies provide evidence that, high rates of compost applications can be used to stabilize and reduce the bioavailability of trace elements in mine waste materials.
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Cline, Terry Lee. "An Evaluation of the School Choice Plan in Charlotte-Mecklenburg Schools and its Perceived Effects on Academic Achievement for all Students." Diss., Virginia Tech, 2006. http://hdl.handle.net/10919/29106.
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Does ethnicity of the student prevent equal levels of learning at an equal pace? Are schools required to teach all children effectively, no matter what their socio-economic status, gender, or ethnicity? Educators and researchers have longed for the answers to these questions. For years, educators have been looking for ways to teach children in schools that are racially identifiable and have the highest percentages of children on free and reduced lunch. School districts that have choice as a way of assigning students are increasing the number of racially identifiable schools. In Charlotte-Mecklenburg Schools, a choice plan was implemented in June 2001. That plan created more schools of poverty within the district. The district also offered additional resources, teacher incentives, and financial assistance as a way to leverage the student make-up of the school district and the individual schools at all levels.Ed. D.
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Pires, Tatiana da Costa Raposo. "Alterações pós-colheita em raízes de mandioquinha-salsa (Arracacia xanthorrhiza Bancroft.): atividade enzimática, identificação de contaminante e caracterização parcial do amido." Universidade de São Paulo, 2005. http://www.teses.usp.br/teses/disponiveis/9/9131/tde-29082017-122147/.
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Este trabalho teve como principais objetivos verificar as alterações na atividade de enzimas amilolíticas, pectinolíticas e celulásicas em raízes de mandioquinha-salsa durante o período pós-colheita, sob diferentes condições de armazenamento, visando avaliar os mecanismos de deterioração das raízes, bem como identificar o microrganismo possivelmente responsável pela alta perecibilidade das raízes. Além disso, foram estudadas características físico-químicas e reológicas do amido de mandioquinha extraído em laboratório. Para a detecção de atividade pectinesterásica (PE) e poligalacturonásica (PG) nas raízes, os parâmetros de extração destas enzimas foram otimizados através de metodologia de superfície de resposta (MSR). As enzimas apresentaram pH ótimo de extração de 7,5 e 4,0 para a PE e PG, respectivamente, sendo os outros parâmetros, como tempo de extração e concentração de NaCI, considerados como não-significativos pelo modelo. As enzimas pectinolíticas parecem estar relacionadas à deterioração das raízes durante o armazenamento, associadas ao amolecimento das raízes. Devido à alta produção de gás, sob condições de temperatura e embalagem, a presença de bactérias produtoras de enzimas pécticas e causadoras de podridão-mole pode ser uma das principais causas da alta perecibilidade das raízes. A atividade amilolítica apresenta um importante papel na deterioração da mandioquinha uma vez os açúcares redutores provenientes da hidrólise do amido podem vir a ser substrato para o ataque de microrganismos oportunistas. Representa um dos principais aspectos metabólicos em um tubérculo rico em amido. A atividade celulásica foi praticamente nula durante o armazenamento. A melhor forma de conservação das raízes ocorreu à temperatura de refrigeração, sob acondicionamento a vácuo. O microrganismo isolado das raízes foi identificado através de provas bioquímicas como Erwinia carotovora subsp. odorífera. Em relação às características físico-químicas, o amido de mandioquinha apresentou um teor de amilose abaixo dos valores determinados para cereais e raízes convencionais (12,1 %) e uma boa estabilidade durante a cocção, analisada através da determinação de viscosidade. A turbidez das suspensões de amido também apresentou estabilidade durante o armazenamento, assim como a sinerese, que.em condições ótimas de preparação do gel apresentou 2,53 % de expulsão de água. Ainda sobre a relação água/gel, o pH da solução e a concentração de amido influenciam significativamente a capacidade de retenção de água, enquanto a temperatura de formação do gel não se mostrou um parâmetro significativo. A textura das preparações de amido foi influenciada significativamente pela temperatura de formação do gel e pela concentração de amido utilizada na preparação. O conhecimento de algumas características reológicas e de propriedades físico-químicas do amido de mandioquinha, visando a aplicação como ingrediente alimentício, pode ser uma alternativa a utilização das raízes in natura, principalmente no que diz respeito ao excedente de safra e ao aproveitamento de raízes com baixo valor comercial.The aim of this work was to verify the changes in amylolytic, pectinolytic and cellulasic activity in Peruvian carrot roots after harvest, under different storage conditions, in order to evaluate the deteriorative mechanisms of the roots, as well as to identify the microorganism possible responsible to its low conservation time. In addition, physico-chemical and rheological characteristics of Peruvian carrot starch were studied. For pectinesterase (PE) and poligalacturonase (PG) detection on the roots, the extraction parameters of both enzymes were optimized by response surface methodology. The enzymes presented the optimum pH values at 7.5 and 4.0 for PE and PG, respectively. Extraction time and NaCI concentration were considered non-significant by the model. Pectic enzymes seams to be related to the deterioration process of Peruvian carrot, that is associated to the root softening. Considering the high volume of gas under specific packing and temperature, the presence of microorganisms soft rot promoters could be the main cause of the high perecibility of the roots. The amylolytic enzymes present an important role on Peruvian carrot deterioration related to the starch hydrolysis and the releasing of reducing sugars, substrate for opportunistic microorganisms. The cellulasic activity was not significant during storage time. Best conditions for roots conservation occurred at 4°C and under vacuum package. The bacteria isolated from the roots were identified by biochemical reactions as Erwinia carotovora subsp. odorifera. Peruvian carrot starch presented low values of amylose content (12.1 %) in comparison to other starch sources and a good stability during cooking, analyzed by viscoamylogram Brabender. The turbidity of starch suspensions presented good stability during storage, as well as water holding capacity, which presented 2.53% in optimal conditions of gel preparation. Syneresis is positively influenced by the pH of past solution and starch concentration whereas temperature of gel formation was not significant. Texture of starch preparations was significant influenced by temperature of gel formation as well as starch concentration. The knowledge of some rheological and physico-chemical properties of Peruvian carrot starch can be useful focusing its use as a food ingredient, which can be an alternative to the consumption of the roots in nature, especially considering crop excesses and low commercial value roots.
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Rodríguez, Nathalie Pérez. "Fractionation of Cu and Fe isotopes in metal-rich mine sites : biotic and abiotic processes." Licentiate thesis, Luleå tekniska universitet, Geovetenskap och miljöteknik, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-26219.
Full textAbstract:
After mineral exploitation the residual grinded and milled material, rich in sulphide minerals and heavy metals, is often left exposed to the atmospheric variables. This weathered mine waste material can lead to the formation of acid mine drainage (AMD) which has negative effects to the environment. The fractionation of stable isotope of metals such as Cu and Fe can be measured using innovative analytical techniques developed recently and could offer a detailed hindsight of the geochemical processes occurring in mine contaminated sites. Tailings profiles from Northern Sweden with high content of Cu and Fe sulphides and in different stages of weathering and/or remediation, along with plant and soil samples from a phytoremediation test site in Ronneburg, Germany were analysed using MC-ICP-MS to measure the isotope ratios of 65Cu/63Cu and 56Fe/54Fe. The analytical method used requires anion exchange chromatography to extract Cu and Fe from a complex matrix prior to the proper isotope ratio measurement. The samples from the tailings profile were useful to interpret the geochemical processes that can lead to a fractionation of Cu and Fe in the field, since redox-driven reactions such as rock oxidation and mineral precipitation are present in such environment. This study shows that precipitation of covellite in a redox-boundary zone in a mine tailings can cause a clear fractionation of Cu (Δ65Curock-covellite= -5.66±0.05‰) and a depletion of the lighter Cu isotope in the oxidised areas of the tailings due to dissolution of the remaining Cu-sulphides. Precipitation of Fe(oxy)hydroxides as a result of the oxidation process of sulphide-bearing rocks can also fractionate Fe, being the precipitated mineral slightly enriched in 56Fe.The influence of soil bacteria and plant uptake in the fractionation of Cu and Fe was investigated in pot and field experiments at the Ronneburg site, where organic amendments were used. The results showed that the plant material was enriched in the lighter Fe isotope compared to the substrate used in the pot and field experiments, in spite of the application of a bacterial consortium. Cu isotope fractionation is more susceptible to the changes in the amendments used, being those bacterial consortium, mychorriza or compost than Fe isotope fractionation. There are differences in the fractionation values in pot and field trials, regardless of the type of organic amendment applied. As an overall view, leaves are enriched in the heavier Cu isotope compared to the soils, regardless of the amendment usedThe application of the results obtained in this work would help not only to offer a view in the cycle of Fe and Cu in the surface environment, and the understanding of the (bio)geochemical processes occurring in sulphide soil surfaces. But also in the way that current remediation techniques of metal contaminated sites could be evaluated, having in mind that simplified systems show a different Cu and Fe fractionation compared to natural systems where more variables are needed to take into account.Godkänd; 2012; 20120816 (natper); LICENTIATSEMINARIUM Ämnesområde: Tillämpad geologi/Applied Geology Uppsats: Fractionation of Cu and Fe Isotopes in Metal-Rich Mine sites: Biotic and Abiotic Processes Examinator: Professor Björn Öhlander, Institutionen för samhällsbyggnad och naturresurser, Luleå tekniska universitet Diskutant: Dr., Project Manager Magnus Land, Kungliga Vetenskapsakademien Tid: Tisdag den 25 september 2012 kl 10.00 Plats: F341, Luleå tekniska universitet
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Bakota, Filip. "Plán pro zvládání sucha a nedostatku vody." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2019. http://www.nusl.cz/ntk/nusl-392180.
Full textAbstract:
The aim of the diploma thesis is to describe and prepare the pilot plan for drought and water scarcity for the selected locality, according to the prepared amendment of water law. Recent years have shown that drought will play a significant role in water supply in the future. Therefore, the need for tools to provide procedures and guidelines for individual administrations is more than important. The first part of the diploma thesis deals with issues of drought and water scarcity, climate change and prospects for the future. The next section describes a plan for drought and water scarcity. In the next parts of the diploma thesis, there are procedures that can mitigate or completely avoid the consequences of drought. From this informations, a pilot study of the plan for drought and water scarcity for the town of Počátky is being prepared in the next part.
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Vallad, Gary Edward. "Potentiation of plant defenses with organic soil amendments /." 2003. http://www.library.wisc.edu/databases/connect/dissertations.html.
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Wang, Jianguo. "Response of Artemisia tridentata ssp. wyomingensis and Stipa thurberiana to nitrogen amendments /." 1988. http://hdl.handle.net/1957/9832.
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Turner, Jason Clemn. "Electrical conductivity and sodium adsorption ratio changes following annual applications of animal manure amendments." 2005. http://digital.library.okstate.edu/etd/umi-okstate-1227.pdf.
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Michael, Patrick Skoth. "Effects of organic amendments and plants on the chemistry of acid sulfate soils under aerobic and anaerobic conditions." Thesis, 2015. http://hdl.handle.net/2440/98723.
Full textAbstract:
Acid sulfate soils with sulfuric horizons (sulfuric soils) can exert a range of negative impacts on the ecology and productivity of soils. The primary treatment for these soils is to raise the pH using lime. Although often effective, this treatment can be expensive and not well suited to large areas. In this research, the possible use of plant organic matter to ameliorate sulfuric soils or to prevent acid sulfate soils with sulfidic materials (sulfidic soils) from acidifying was investigated. The advantage of this approach is that organic matter is readily available, inexpensive and environmentally friendly, especially in Ramsar listed wetlands where lime cannot be used. The experimental treatments used ground leaves of Phragmites, lucerne hay, pea straw and wheat straw as sources of organic matter with varying nitrogen, which were either incorporated into or overlaid on the surface of the soils. After 6 months of incubation under either aerobic or anaerobic soil conditions, pH, Eh and sulfate content were measured. Incorporation of complex organic matter significantly increased the pH of both sulfuric and sulfidic soils. These changes were correlated with reductions in soil redox and sulfate content. The magnitude of the changes depended on the nitrogen content of the complex organic matter. The relative importance of carbon and nitrogen in ameliorating acid sulfate soils was further investigated respectively using glucose, sodium acetate and molasses as simple carbon sources, and urea, nitrate and ammonium as simple nitrogen compounds. It was found that compounds containing inorganic nitrogen alone without carbon were ineffective, while urea significantly increased pH and reduced Eh, but did not affect the sulfate content of the soil. Glucose had no significant effect on sulfuric soils, either at low (catalytic) or high concentrations, while acetate significantly increased pH. Molasses (which may contain small amounts of nitrogen) caused moderate changes in pH, Eh and sulfate content. On sulfidic soils, acetate prevented oxidation but glucose strongly acidified the soil, most probably by fermentation to butyric acid. The effects of live roots on sulfidic and sulfuric soil chemistry under either aerobic or anaerobic soil conditions were investigated using Typha, Phragmites and Melaleuca. Typha and Melaleuca are respectively common wetland and inland plants, whereas Phragmites grows under both wetland and inland soil conditions. The study was extended to investigate the combined effects of incorporated ground Phragmites leaves as organic matter and Phragmites plants together. Generally, a great deal of variability was found in the changes in pH, redox and sulfate content, the overall effects being dependent on plant type, whether there was incorporated organic matter, the type of soil and the moisture conditions. However, in all cases the growth of the live plants resulted in greater acidity than in the unplanted control soils. In the case of Typha and Phragmites, which have aerenchymatous tissues, the acidification under anaerobic conditions was attributed to the transport of oxygen in these tissues into the soil. Under non-flooded conditions, the acidification was most likely due to increased oxygen penetration as a result of loosening of the soil by the plant roots.Thesis (Ph.D.) (Research by Publication) -- University of Adelaide, School of Biological Sciences, 2015.
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Blue, Jarrod Dwayne. "Soil nitrogen amendments and insect herbivory alter above-and belowground plant biomass in an old-field ecosystem." 2010. http://trace.tennessee.edu/utk_gradthes/688.
Full textAbstract:
Nutrient availability and herbivory can regulate primary production in ecosystems, but little is known about how, or whether, they may interact with one another. Here I investigate how nitrogen availability and insect herbivory interact to alter above- and belowground plant community biomass in an old-field ecosystem. In 2004, 36 experimental plots were established in which soil nitrogen (N) availability (at three levels) was manipulated and insect abundance (at two levels) in a completely randomized plot design. In 2009, after six years of treatment, I measured aboveground biomass and assessed root production at peak growth. Overall, I found a significant effect of soil N availability on both above- and belowground plant biomass while insects affected only aboveground biomass of subdominant plant species and coarse root production; there were no statistical interactions between N availability and insect herbivory for any response variable. Specifically, responses of aboveground and belowground community biomass to nutrients were driven by reductions in soil N, but not additions, indicating that soil N may not be primarily limiting production in this ecosystem. Insect herbivory altered the aboveground biomass of the subdominant plant species and altered allocation patterns to coarse root production belowground. Overall, the results of six years of nutrient amendments and insect removals suggest strong bottom-up influences on total plant community productivity.
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Cox, Bonnie S. Hoffman. "Serial manure amendments : effects on soil properties and root rot of sweet corn." Thesis, 2005. http://hdl.handle.net/1957/27796.
Full textAbstract:
The effect of serial (multiple-year) organic matter (OM) amendment on
soil properties has been described in some cropping systems, although less is
known about the effect of serially amended field soils on soil-borne plant diseases.
The objectives of this study were to describe the effects of the third and fourth
years of annual, serial amendment with dairy manure solids on 1) soil physical and
biological properties and 2) severity of sweet corn root rot. Plots were amended
with five rates of separated dairy manure solids annually for three years. In the
fourth year, plots were split and only half of each plot was re-amended. Soil
physical properties [bulk density, free and occluded particulate organic matter
(POM), soil water retention, total porosity, gravimetric moisture content] and
biological properties [microbial activity (as hydrolysis of fluorescein diacetate;
FDA) and microbial biomass-C] were assessed each year in all treatments. Root
rot severity was assessed in situ and in the greenhouse with multiple sweet corn
(Zea mays L. cv Golden Jubilee) bioassays conducted in the amended field soils.
Necrosis of the radicle and nodal roots was assessed when plants reached the 6-
leaf stage. Amendment rate was positively associated with increases in soil
properties that serve as indicators of soil quality, such as POM content, total
porosity, microbial biomass, and FDA activity. In the third year after amendment,
weak root rot suppression was observed in-field and was associated with FDA
activity. By the fourth year of serial amendment this trend was no longer evident,
however evidence from the high-rate treatment that was not re-amended (3HNRA)
pointed to an emerging suppressive mechanism that persisted up to 13
months after the third amendment. Factors that may be interacting over time to
generate observed disease suppression in these serially amended soils include:
short-term post-amendment microbiostasis, soil moisture retention, inoculum
potential, and a novel suppressive mechanism.Graduation date: 2006
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Sutton-Grier, Ariana E. "The Role of Plant Functional Diversity and Soil Amendments in Regulating Plant Biomass and Soil Biogeochemistry in Restored Wetland Ecosystems in the North Carolina Piedmont." Diss., 2008. http://hdl.handle.net/10161/620.
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Graff, Joseph Edward. "Ionic balance and the constituent organic acids of current-year foliage of western redcedar, western hemlock, and Douglas-fir seedlings /." 1993. http://hdl.handle.net/1957/10705.
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Cespedes, Leon Maria Cecilia. "Organic soil amendements (sic) : impacts on snap bean common root rot and soil quality." Thesis, 2002. http://hdl.handle.net/1957/32042.
Full textAbstract:
Common root rot is a major disease of commercially grown snap bean
(Phaseolus vulgaris L.) on the irrigated sandy soils of central Wisconsin. The
objective of this study was to determine the relationships between soil properties
and suppressiveness to common root rot of snap bean (causal agent Aphanomyces
euteiches) in soils. The soils had been annually amended for three years in a field
trial on a Plainfield sandy loam in Hancock, WI. Soils were amended each year
from 1998 to 2001 with three rates of fresh paper-mill residuals (0, 22 or 33 dry Mg
ha�����) or composted paper-mill residuals (0, 38 or 76 dry Mg ha�����). Soil was
removed from each treatment in April (one year after last amendment) and brought
to the laboratory. This was repeated with a field soil sample taken in September,
2001. The soils from the two samplings were incubated at room temperature and
periodically assayed (days 9, 44, 84, 106, 137, 225 and 270 for April sampling)
(days 13, 88 and 174 for September sampling) for suppressiveness of snap bean
root rot (0 to 4 where 0=healthy and 4=dead plant). The same days, incubated
soils were characterized for ��-glucosidase, arylsulfatase and fluorescein diacetate
activities; microbial biomass C (by chloroform fumigation); water stable
aggregation (WSA) and total C. In the first incubation, there were large differences
between field amendment treatments in terms of snap bean root rot incidence. The
disease was suppressed by both fresh and composted amendments, but compost
was most suppressive at high compost rates with disease incidence <40% which are
considered healthy plants that can reach full yield potential. In the second
incubation, disease severity difference among treatments were similar to the first
incubation. This would indicate the suppression was induced prior to initiation of
this experiment.
Disease severity of bean plants grown in unamended field soil was high but
in amended soils tended to decrease in intensity over time. Root rot severity was
negatively related to ��-glucosidase, and microbial biomass at the beginning and the
end of the first incubation period, respectively. FDA hydrolysis was not correlated
with disease severity and WSA moderately correlated with disease. The best
indicator of disease severity was arylsulfatase which was significantly and
negatively correlated with disease severity in 4 of 5 sampling periods.Graduation date: 2003