Biofumigation is an important crop protection practice that uses a plant’s natural defence mechanisms to control agricultural crop pathogens and diseases. Glucosinolates are volatile compounds found in most Brassica species and when hydrolysed, it forms a range of natural toxins including isothiocyanates that act as biofumigants. Research suggests that biofumigation is a good alternative to chemical fumigants as it is effective in controlling plant pests but with lower health and environmental risks. Several studies have confirmed the effectiveness of the breakdown products, especially isothiocyanates, as fungicidal, bactericidal and nematicidal products against a series of plant pests. However, very little information is available on the effects of glucosinolates and its breakdown products on non-target and beneficial soil organisms. Negative effects on beneficial soil organisms can have serious negative impacts on soil quality especially when essential ecosystem functions such as nutrient cycling and soil bioturbation are affected. Three biofumigants, broccoli, mustard and oilseed radish, and two chemical fumigants, metham sodium and cadusafos, were investigated for possible effects on non-target and essential soil organisms such as earthworms and the soil microbial community. Sublethal endpoints, including growth and reproductive success of the earthworms, were monitored. The genotoxicity of the biologically active compounds found in the fumigants, towards earthworms, was evaluated by means of the comet assay. The DNA damage was quantified by tail intensity parameters. Furthermore, the changes in the soil microbial community function and structure were evaluated by means of community level physiological profiling (CLPP) and phospholipid fatty acid (PLFA) analyses respectively. All exposures were done in artificial soil prepared according to the OECD standard guidelines. In the biofumigant treated soils, results varied and different effects were observed on the non-target soil organisms. Broccoli reduced cocoon production and the number of hatchlings while mustard induced more DNA strand breaks in earthworm cells compared to the control. All the biofumigants stimulated microbial growth but broccoli and oilseed radish changed the microbial functional diversity. Mustard had no lasting effect on the functional diversity but altered the microbial community structure. The chemical fumigants had a marked negative impact on the survival, growth, reproduction and the genotoxicity of the earthworms with metham sodium causing greater harm than cadusafos. The effects on the microbial community varied. Both chemicals had an inhibitory effect on the microbial growth in terms of the viable biomass determined by PLFA and the average well colour development in the Biolog™ Ecoplates. No lasting effects were observed in the community structure. Overall, cadusafos had a more pronounced effect on the microbial community functional diversity than metham sodium. Results indicated that each bioindicator species illustrates effects at their own level of organisation / MSc (Environmental Sciences), North-West University, Potchefstroom Campus, 2015

Biofumigation is an important crop protection practice that uses a plant’s natural defence mechanisms to control agricultural crop pathogens and diseases. Glucosinolates are volatile compounds found in most Brassica species and when hydrolysed, it forms a range of natural toxins including isothiocyanates that act as biofumigants. Research suggests that biofumigation is a good alternative to chemical fumigants as it is effective in controlling plant pests but with lower health and environmental risks. Several studies have confirmed the effectiveness of the breakdown products, especially isothiocyanates, as fungicidal, bactericidal and nematicidal products against a series of plant pests. However, very little information is available on the effects of glucosinolates and its breakdown products on non-target and beneficial soil organisms. Negative effects on beneficial soil organisms can have serious negative impacts on soil quality especially when essential ecosystem functions such as nutrient cycling and soil bioturbation are affected. Three biofumigants, broccoli, mustard and oilseed radish, and two chemical fumigants, metham sodium and cadusafos, were investigated for possible effects on non-target and essential soil organisms such as earthworms and the soil microbial community. Sublethal endpoints, including growth and reproductive success of the earthworms, were monitored. The genotoxicity of the biologically active compounds found in the fumigants, towards earthworms, was evaluated by means of the comet assay. The DNA damage was quantified by tail intensity parameters. Furthermore, the changes in the soil microbial community function and structure were evaluated by means of community level physiological profiling (CLPP) and phospholipid fatty acid (PLFA) analyses respectively. All exposures were done in artificial soil prepared according to the OECD standard guidelines. In the biofumigant treated soils, results varied and different effects were observed on the non-target soil organisms. Broccoli reduced cocoon production and the number of hatchlings while mustard induced more DNA strand breaks in earthworm cells compared to the control. All the biofumigants stimulated microbial growth but broccoli and oilseed radish changed the microbial functional diversity. Mustard had no lasting effect on the functional diversity but altered the microbial community structure. The chemical fumigants had a marked negative impact on the survival, growth, reproduction and the genotoxicity of the earthworms with metham sodium causing greater harm than cadusafos. The effects on the microbial community varied. Both chemicals had an inhibitory effect on the microbial growth in terms of the viable biomass determined by PLFA and the average well colour development in the Biolog™ Ecoplates. No lasting effects were observed in the community structure. Overall, cadusafos had a more pronounced effect on the microbial community functional diversity than metham sodium. Results indicated that each bioindicator species illustrates effects at their own level of organisation / MSc (Environmental Sciences), North-West University, Potchefstroom Campus, 2015

Objective was to assess the toxicity of chromium (Cr) contaminated soil (CS) using the earthworm Lumbricus terrestris. Specific aims were to determine: (1) survival (LC50); .(2) immunotoxicity as indicated by lysozyme activity, coelomocyte counts, secretory (SR) and erythrocyte rosette (ER) formation, and phagocytosis; and (3) compare effects of CS exposure with those of Cr spiked artificial soil (AS) . CS Cr concentration was 8.78 mg/g with 98.2% being Cr^3+ and 1.8% being Cr^6+. Using 14 d AS protocol the LC50 was 6.49% CS: AS mixture. CS concentrations of 0.5, 1.0, 2.5 and 5.0% were sublethal, whereas 6.25, 12.5, 25, 50 and 100% CS were lethal. Sublethal exposure caused no immuno- modulation. Exposure to 50% CS: AS mixture for 5 d caused reduced SR and ER formation. Exposure to AS spiked with 0.27% Cr for 5 d resulted in immunomodulation equivalent to 50% CS: AS mixtures. Results indicated the CS to be acutely toxic.

Contaminated areas resulting from anthropogenic activities have, for the most part, concentrations of contaminants that exceed Tier 1 standards below which the risk is considered acceptable. However, contaminants that have been in soil for a prolonged period can become recalcitrant over time, due to various physico-chemical and biological processes. Sequestered and recalcitrant contaminants are not readily biologically available to living organisms. However, they are easily measured analytically because of the strong acid extractions that are used in the analytical methodologies. Because toxicity is a function of exposure concentration(s), exposure duration, and bioavailability, contaminants in soil can be present at concentrations that exceed established standards but they represent minimal risk to ecological receptors because the contaminants are not fully available. To predict toxicity and estimate risk, it is imperative that an accurate and reliable measure of bioavailability be available. Several surrogate measures of bioavailability were compared to the results of a battery of toxicity tests using Cu, Pb, and Zn-contaminated soils collected from a former industrial area and Cu and Zn-contaminated soils collected from a former mining site. CaCl₂extractions, hydroxypropyl-β-cyclodextrin (cyclodextrin) extractions, Simulated Earthworm Gut (SEG) tests, and bioaccumulation tests were performed using the soils. Overall, SEG-extractable Cu was most predictive of adverse effects in industrial soils, likely due to enzymatic activity and/or increased ionic strength of the solution. For the mining soils, all chemical measures of bioavailability correlated with several biological responses; however, CaCl₂-extractable Cu and SEG-extractable Cu and Zn best predicted earthworm responses. Total Cu concentrations in soil correlated best with adverse effects to plants. No method was a good predictor of all biological effects for a single organism when data from the two sites were combined. The SEG test may provide a good indication of metal toxicity at contaminated sites with varying soil physico-chemical characteristics but further validation is required.

Contaminated areas resulting from anthropogenic activities have, for the most part, concentrations of contaminants that exceed Tier 1 standards below which the risk is considered acceptable. However, contaminants that have been in soil for a prolonged period can become recalcitrant over time, due to various physico-chemical and biological processes. Sequestered and recalcitrant contaminants are not readily biologically available to living organisms. However, they are easily measured analytically because of the strong acid extractions that are used in the analytical methodologies. Because toxicity is a function of exposure concentration(s), exposure duration, and bioavailability, contaminants in soil can be present at concentrations that exceed established standards but they represent minimal risk to ecological receptors because the contaminants are not fully available. To predict toxicity and estimate risk, it is imperative that an accurate and reliable measure of bioavailability be available. Several surrogate measures of bioavailability were compared to the results of a battery of toxicity tests using Cu, Pb, and Zn-contaminated soils collected from a former industrial area and Cu and Zn-contaminated soils collected from a former mining site. CaCl₂extractions, hydroxypropyl-β-cyclodextrin (cyclodextrin) extractions, Simulated Earthworm Gut (SEG) tests, and bioaccumulation tests were performed using the soils. Overall, SEG-extractable Cu was most predictive of adverse effects in industrial soils, likely due to enzymatic activity and/or increased ionic strength of the solution. For the mining soils, all chemical measures of bioavailability correlated with several biological responses; however, CaCl₂-extractable Cu and SEG-extractable Cu and Zn best predicted earthworm responses. Total Cu concentrations in soil correlated best with adverse effects to plants. No method was a good predictor of all biological effects for a single organism when data from the two sites were combined. The SEG test may provide a good indication of metal toxicity at contaminated sites with varying soil physico-chemical characteristics but further validation is required.

Agriculture is the principal land use throughout Europe and agricultural intensification has been implicated in large reductions in biodiversity, with the negative effects on birds particularly well documented. The lapwing (Vanellus vanellus) is one such species where changes in farming practices has reduced the suitability and quality of breeding habitat, leading to a drop in population size that has been so severe as to warrant its addition to the Red List of Birds of Conservation Concern in the UK. Lowland areas, where agricultural intensification has generally been most pronounced, have been worst affected, however, more recently declines in marginal upland areas, previously considered refuges for breeding wader populations, have been identified. An upland livestock farm in Stirlingshire that uses an in-bye system of fodder crop management and has unusually high densities of breeding lapwings provides a basis for this project to test causal hypotheses for the decline of upland lapwing populations and to identify potential conservation management solutions. Specifically this farm plants a forage brassica in an in-bye field for two consecutive years, followed by reseeding with grass and seven, out of sixteen, in-bye fields have undergone this regime at the study site since 1997. Fields that had undergone fodder crop management supported almost 60% more lapwings than comparable fields that had not previously been planted with the fodder crop. Lapwing density was highest in the year after the fodder crop was planted, once it had been grazed, which results in a high percentage of bare ground, likely to be attractive to nesting lapwings. Lapwing densities remained above that which occurred in fields that had not undergone fodder crop management for a further four years after the field had been returned to grass. The effect of management on lapwing food resources and nesting structure was tested through a field experiment; liming increased the abundance of Allolobophora chlorotica, an earthworm species that was associated with chick foraging location at the study site, suggesting that lapwings may benefit from liming conducted as part of fodder crop management. The relationship between lapwings and soil pH is further explored across 89 sites on mainland Scotland, using soil property data to improve the predictive power of habitat association models, something which has not previously been done for any farmland bird. Adding soil and topographical data to habitat models, based on established relationships between breeding lapwings and their habitat, improved model fit by almost 60%, indicating that soil properties influence the distribution of this species. The density of breeding lapwings was highest at higher altitude sites, but only when the soil was relatively less peaty and less acidic, providing further support for the hypothesis that agricultural liming benefits lapwings. In addition to assessing the conservation benefit of fodder crop management, the economic costs are also considered. Fodder crop management provides a source of livestock fodder in the autumn and winter during a period when forage demands outstrip grass growth, and ultimately improves the grazing quality of the grass that is replaced; this system currently operates outside of any agri-environment scheme (AES). However, at the study site, planting of the fodder crop and grass is delayed to avoid agriculture operations during the breeding season, which reduces yield and hence profitability. An initial estimate of £200 ha-1 is suggested as an incentive to encourage wider adoption of fodder crop management in a “lapwing friendly” manner, although further work is required to determine if this payment level is appropriate and the current method of AES implementation may limit the suitability of fodder crop management as an AES. The results indicate that agricultural liming could benefit breeding lapwings in pasture fields where soil pH falls below pH 5.2, by increasing earthworm abundance. Where soil pH is below pH 5.2, liming should provide a cost effective mechanism for farmers to improve grass yields. Regular soil testing and liming in response to low pH, within improved or semi-improved grassland fields, where management activities such as use of nitrogen fertiliser can contribute to soil acidification, should be advocated to farmers in marginal areas as a mechanism for improving grass productivity whilst potentially benefitting breeding lapwing and other species where earthworms contribute significantly to their diet.

In Magister work the spreading of macro fauna (Lumbricidae) in agrofitocenosis. Work object: research made in southwest Lithuania, Vilkaviškis region in the intensive agriculture farming in the hard granules ground. Aim of the work: to evaluate by field research southwest Lithuania hard granules soil macro fauna (Lumbricidae) spreading in agrofitocenosis depending on the kinds of growing plants, prior planting and hydrothermical regime. The methods of work: earthworm quantity was made digging 0,5 x 0,5m 2 and 0,25cm deep soil monolities and counting earthworms. By the research established that for earthworm quantity had influence growing plants, and their prior planting and hydrothermical regime. Most useful prior planting were barleys and long year grass. During research years between hydrothermical regime and earthworm number was defined strong and medium correlation relations.

Conselho Nacional de Desenvolvimento Científico e Tecnológico / The indiscriminate use of agricultural supplies can cause soil pollution, affecting the flora, fauna and ecological relationships. Among these chemical compounds used in agriculture, there is the Bordeaux mixture. The intense use of this fungicide results in a considerable copper addition in the soil, may cause damage to exposed organisms. This study aimed to evaluate the toxicological effects of different copper doses, (0, 35, 70, 105, 140 e 175 mg.Kg-1) applied in soil, at earthworms Eisenia andrei biomass and reproduction, through ecotoxicological tests as well as the effects of exposure to antioxidant enzyme activity, by the enzymes catalase and glutathione S-transferase (GST and CAT), on neurotransmission biomarkers such as acetylcholinesterase (AChE) and cell membrane lipid peroxidation through the levels of malondialdehyde (MDA). The ecotoxicological results showed that the largest copper doses tested, (140 e 175 mg.Kg-1) were toxic, because the worms had a mean biomass reduction and cocoons. In the enzyme assessments, an increase in the glutathione-S-transferase activity was observed as the antioxidant defense mechanism. The significant MDA levels increase and the acetylcholinesterase activity inhibition, indicating the cell membrane lipid peroxidation occurrence and neurotransmission changes as a result of oxidative stress caused by the metal. / O uso indiscriminado de insumos agrícolas pode causar a poluição dos solos, comprometendo a flora, fauna e as relações ecológicas. Dentre os insumos químicos utilizados na agricultura, destaca-se a calda bordalesa. Sua intensa utilização resulta em uma adição considerável de cobre ao solo, podendo causar danos aos organismos expostos. O presente estudo teve como objetivo determinar os efeitos toxicológicos de diferentes doses de cobre: 0, 35, 70, 105, 140 e 175 mg.Kg-1 aplicado ao solo, na biomassa e reprodução das minhocas Eisenia andrei, através dos testes ecotoxicológicos assim como os efeitos da exposição a nível enzimático antioxidante, através das enzimas catalase e glutationa S-transferase (CAT e GST), sobre biomarcadores de neurotransmissão como a acetil-colinesterase (AChE) e na peroxidação lipídica da membrana celular através dos níveis de malondialdeído (MDA). Os resultados ecotoxicológicos, evidenciaram que as maiores doses de cobre testadas, (140 e 175 mg.Kg-1) foram tóxicas, pois as minhocas apresentaram redução média na biomassa e no número de casulos. Em relação aos níveis enzimáticos, foi observado um incremento na atividade das enzimas glutationa-S-transferase, como mecanismo de defesa antioxidante. O aumento significativo nos níveis de MDA observados e a inibição da atividade da acetil-colinesterase, indicam a ocorrência da peroxidação lipídica da membrana celular e alterações na neurotransmissão em decorrência do estresse oxidativo ocasionado pela presença do metal.

There are concerns that genetic modification of maize with Bacillus thuringiensis may influence its structural and chemical composition which, together with the Cry1Ab proteins, may affect agro-ecosystem processes and feed quality. This study was aimed at investigating the expression of Cry1Ab protein in leaves, stems and roots of Bt maize and the effect of genetic modification (MON810) on activity of earthworms, silage quality and decomposition of residues in the field. In 2009/10 four maize cultivars; DKC61-25B, DKC61-24, PAN6Q-321B and PAN6777 were planted. Expression of Cry1Ab in leaves, stems and roots was analyzed at 6, 8, 10 and 12 weeks after planting (WAP). Earthworms were also sampled from the same treatments at 6, 9 and 18 WAP. Two silage experiments were conducted using maize cultivars, DKC80-12B and DKC80-10 produced in the 2008/09 season and DKC61-25B, DKC61-24, PAN6Q-321B and PAN6777, produced in 2009/10. The silage was sampled at 0, 2, 4, 8, 15 and 42 days in 2008/09 and 0, 8 and 42 days in 2009/10 and analyzed for Ash Free Dry Matter, Crude Fiber, Neutral Detergent Fiber, Acid Detergent Fiber, Acid Detergent Lignin, Crude Protein and Total Digestible Nutrients. Two litter-bag decomposition studies were also carried out (i) in 2008 (surface applied) using maize cultivars DKC80-12B, DKC80-10 and DKC6-125 residues and (ii) in 2009 (soil incorporated) using DKC75-15B, CRN3505, PAN6Q-321B v and PAN6Q-121. Ash-free dry matter and Cry1Ab protein were measured throughout the incubation time. There were no differences between DKC61-25B and PAN6Q-321B in terms of expression of Cry1Ab in leaves, stems and roots over time. The Cry1Ab expression levels were in decreasing order: leaves > stems > roots. No effects of Bt maize on earthworm numbers and biomass were observed. There were no differences in all silages parameters except NDF and ADF, which were higher in the Bt maize silage than that of the non-Bt maize from the 2008/09 season. The Cry1Ab levels were essentially not reduced during ensiling. The maize residues (both Bt and non-Bt maize) degraded to similar levels, either when surface-applied or incorporated into soil but soil-incorporated residues decomposed faster than surface-applied ones. Cry1Ab degraded as the plant matrix decomposed. The findings suggested that maize genetically modified with the Bt MON810 event can be grown in the Central Eastern Cape without affecting earthworm numbers and biomass, silage quality and decomposition of maize residues.

京都大学 / 0048 / 新制・課程博士 / 博士(農学) / 甲第21826号 / 農博第2339号 / 新制||農||1067(附属図書館) / 学位論文||H31||N5198(農学部図書室) / 京都大学大学院農学研究科地域環境科学専攻 / (主査)准教授 髙橋 知之, 教授 北山 兼弘, 准教授 刑部 正博 / 学位規則第4条第1項該当 / Doctor of Agricultural Science / Kyoto University / DFAM