The Experts below are selected from a list of 192 Experts worldwide ranked by ideXlab platform
Ralph Meissner - One of the best experts on this subject based on the ideXlab platform.
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plant available phosphorus in soil as predictor for the leaching potential insights from long term Lysimeter Studies
AMBIO: A Journal of the Human Environment, 2018Co-Authors: Holger Rupp, Ralph Meissner, Peter LeinweberAbstract:This study aimed to demonstrate the impact of phosphorus (P) mineral fertilization on topsoil P content and P leaching. We evaluated 83 datasets from 25 years from Lysimeter experiments involving different cropping systems (winter crop, summer crop and autumn tillage, harvested grass) or unfertilized fallow, four types of soil texture, and three levels of applied mineral P fertilizer. A positive monotonic and significant correlation was indicated between P in the topsoil determined by the double lactate method (P DL) and the yearly flow-weight total (TP) concentrations in leachates with Spearman rank correlations r s (r s > 0.183) and probability (p) < 0.05. The present German recommended rates of P mineral fertilization are proposed insufficient to protect fresh and marine waters from undesired P pollution and eutrophication. A long-term reduction of excess soil P is urgent along with other measures to mitigate high P inputs to surface and ground waters.
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influence of different agricultural management systems on nitrogen leaching results of Lysimeter Studies
Journal of Plant Nutrition and Soil Science, 2002Co-Authors: Siegfried Knappe, Ulrike Haferkorn, Ralph MeissnerAbstract:The objective was to estimate the potential risk of N leaching into the groundwater under various types of agriculture by using Lysimeter experiments on the nitrogen(N)-cycle of various soil types. Results were obtained with 12 weighable, monolithic Lysimeters with a surface area of 1 m2, a total depth of 3 m, and free drainage. Mean annual N-leaching losses of 5 to 44 kg ha—1 and nitrate concentrations of the seepage water (leachate) between 80 and 200 mg l—1 were measured during the period of intensive agricultural use. On fallow land with a well-established grass vegetation, some nitrate was removed by the plants. As a result, the nitrate concentrations in the leachate were reduced significantly. Ecological farming measures generally reduced N leaching losses and kept the N-concentration in the leachate below the German threshold value for drinking water with 50 mg l—1 nitrate. However, ploughing in of clover or leguminous vegetation and the application of farmyard manure in autumn caused the nitrate concentration in the leachate to rise significantly above the mentioned threshold value. Einfluss unterschiedlicher landwirtschaftlicher Nutzungsformen auf den Stickstoffaustrag: Ergebnisse von Lysimeteruntersuchungen Das Ziel der Untersuchungen bestand in der Abschatzung des Stickstoff (N) — Auswaschungspotenzials bei differenzierter Intensitat der ackerbaulichen Nutzung und verschiedenen Bodenformen. Dazu wurden langjahrige Messreihen von 3 m tiefen und 1 m2 grosen, monolithischen Lysimetern ausgewertet. Es wurden bei intensiver landwirtschaftlicher Nutzung im Mittel N-Austrage von 5 bis 44 kg ha—1 a—1 und Nitratgehalte von 80 bis 200 mg l—1 ermittelt. Begrunte Brache mit gut etablierten Grasbestanden war in der Lage, N-Uberschusse festzulegen. Mit den Masnahmen des okologischen Landbaues wurden N-Austrag und Nitratgehalt im Sickerwasser unter den in Deutschland geltenden Grenzwert fur Trinkwasser in Hohe von 50 mg l—1 abgesenkt. Der fur eine bessere Nahrstoffversorgung im okologischen (biologisch-dynamischen) Landbau ubliche Umbruch von Kleegras und Leguminosenbestanden und die Ausbringung von Stalldung bewirkten eine deutliche Erhohung der Nitratgehalte im Sickerwasser uber den bestehenden Nitrat-Grenzwert.
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Estimating the effects of set‐aside on water quality: scaling‐up of Lysimeter Studies
Land Degradation & Development, 1999Co-Authors: Ralph Meissner, Joe Seeger, Holger Rupp, P SchonertAbstract:Since 1990, agriculture in the five new federal states of Germany has experienced a fundamental structural change. As much as 10 per cent of the 6·2 million ha of previously intensively farmed agricultural land were set-aside abruptly. In the spring of 1991, a Lysimeter trial (filled with soils common in the catchment area of the Elbe River), was set up to investigate the impact of set-aside on the water and solute balance. The Studies proved that restricting agricultural use in areas previously farmed intensively by converting them into permanent or rotation fallow will result in measurable changes in deep percolation (ground-water recharge) and water quality in less than one year. The results of the Lysimeter Studies were extrapolated to calculate the effects of set-aside in a catchment area (about 2 500 ha) with similar meteorological and soil conditions. The calculations showed that increasing the area under rotation fallow from 8 to 15 per cent increases the nitrogen load of the stream draining the catchment by about 5 per cent. Copyright © 1999 John Wiley & Sons, Ltd.
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estimating the effects of set aside on water quality scaling up of Lysimeter Studies
Land Degradation & Development, 1999Co-Authors: Ralph Meissner, Joe Seeger, Holger Rupp, P SchonertAbstract:Since 1990, agriculture in the five new federal states of Germany has experienced a fundamental structural change. As much as 10 per cent of the 6·2 million ha of previously intensively farmed agricultural land were set-aside abruptly. In the spring of 1991, a Lysimeter trial (filled with soils common in the catchment area of the Elbe River), was set up to investigate the impact of set-aside on the water and solute balance. The Studies proved that restricting agricultural use in areas previously farmed intensively by converting them into permanent or rotation fallow will result in measurable changes in deep percolation (ground-water recharge) and water quality in less than one year. The results of the Lysimeter Studies were extrapolated to calculate the effects of set-aside in a catchment area (about 2 500 ha) with similar meteorological and soil conditions. The calculations showed that increasing the area under rotation fallow from 8 to 15 per cent increases the nitrogen load of the stream draining the catchment by about 5 per cent. Copyright © 1999 John Wiley & Sons, Ltd.
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Lysimeter Studies in East Germany concerning the influence of set aside of intensively farmed land on the seepage water quality
Agriculture Ecosystems & Environment, 1998Co-Authors: Ralph Meissner, Joe Seeger, Holger RuppAbstract:Abstract Since 1990, the five new federal states of Germany have experienced a fundamental structural change in agriculture. As much as 10% of the 6.2 million hectares of the previously intensively farmed agricultural areas were abruptly set aside. In the spring of 1991, a Lysimeter test, designed in 1983 to maximize yields, was adapted to these new agricultural conditions. The purpose of the test was to investigate the impact of the structural changes on water balance and budget of materials. Leaching of relevant cations (Ca 2+ , Mg 2+ , Na + , and K + ) and anions (total PO 4 3− , NO 3 − , Cl − , and SO 4 2− ) contained in the seepage water as well as the resulting pH-values were determined for various types of set aside. The reference treatment consisted of intensively farmed Lysimeters following the principles of BMP (best management practices). The tests covered a period of three years. The Studies proved that restricting agricultural usage on areas previously farmed heavily, by converting them into permanent or rotation fallow, will result in measurable changes of seepage water recharge and quality within less than one year. The permanent fallow showed large leaching losses of the measured cations even three years after set aside. In contrast, the leaching of the measured anions NO 3 − , SO 4 2− and Cl − decreased significantly compared with the initial level. If cation leaching decreases from lack of additional supply, a shift of the pH into the acid range is to be expected. A one year set aside in the form of a rotation fallow is connected with increased leaching of nitrate. Compared with intensively farmed agricultural land, nitrate leaching in the year of set aside is increased by approximately 55% and in the year of resuming intensive agricultural production by 30%.
P Schonert - One of the best experts on this subject based on the ideXlab platform.
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Estimating the effects of set‐aside on water quality: scaling‐up of Lysimeter Studies
Land Degradation & Development, 1999Co-Authors: Ralph Meissner, Joe Seeger, Holger Rupp, P SchonertAbstract:Since 1990, agriculture in the five new federal states of Germany has experienced a fundamental structural change. As much as 10 per cent of the 6·2 million ha of previously intensively farmed agricultural land were set-aside abruptly. In the spring of 1991, a Lysimeter trial (filled with soils common in the catchment area of the Elbe River), was set up to investigate the impact of set-aside on the water and solute balance. The Studies proved that restricting agricultural use in areas previously farmed intensively by converting them into permanent or rotation fallow will result in measurable changes in deep percolation (ground-water recharge) and water quality in less than one year. The results of the Lysimeter Studies were extrapolated to calculate the effects of set-aside in a catchment area (about 2 500 ha) with similar meteorological and soil conditions. The calculations showed that increasing the area under rotation fallow from 8 to 15 per cent increases the nitrogen load of the stream draining the catchment by about 5 per cent. Copyright © 1999 John Wiley & Sons, Ltd.
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estimating the effects of set aside on water quality scaling up of Lysimeter Studies
Land Degradation & Development, 1999Co-Authors: Ralph Meissner, Joe Seeger, Holger Rupp, P SchonertAbstract:Since 1990, agriculture in the five new federal states of Germany has experienced a fundamental structural change. As much as 10 per cent of the 6·2 million ha of previously intensively farmed agricultural land were set-aside abruptly. In the spring of 1991, a Lysimeter trial (filled with soils common in the catchment area of the Elbe River), was set up to investigate the impact of set-aside on the water and solute balance. The Studies proved that restricting agricultural use in areas previously farmed intensively by converting them into permanent or rotation fallow will result in measurable changes in deep percolation (ground-water recharge) and water quality in less than one year. The results of the Lysimeter Studies were extrapolated to calculate the effects of set-aside in a catchment area (about 2 500 ha) with similar meteorological and soil conditions. The calculations showed that increasing the area under rotation fallow from 8 to 15 per cent increases the nitrogen load of the stream draining the catchment by about 5 per cent. Copyright © 1999 John Wiley & Sons, Ltd.
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influence of mineral fertilizers and different soil types on nutrient leaching results of Lysimeter Studies in east germany
Land Degradation & Development, 1995Co-Authors: Ralph Meissner, Holger Rupp, J Seeger, P SchonertAbstract:A Lysimeter experiment on mineral fertilizer use and soil type was begun in 1985 to study the interrelationships between the level of mineral fertilization and the leaching of nutrients. Increased application of mineral fertilizers brought about not only a significant reduction in effluence build-up, but also a significant increase in yield. The lowest levels of nitrogen leaching were found in clay-sand soil in use as grassland, and the highest in sandy soil used as arable land. Unexpectedly, the study was unable to prove statistically that a reduction in N, P and K leaching follows automatically from a reduction in mineral fertilization. Hence, suboptimal fertilization cannot be the only corrective measure if a noticeable or marked reduction in the adverse impact on water quality due to nutrient leaching is to be achieved. Interim plantings should be integrated in crop rotations. Agricultural crops must be siteadapted and suited to the fertilization regime.
Holger Rupp - One of the best experts on this subject based on the ideXlab platform.
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plant available phosphorus in soil as predictor for the leaching potential insights from long term Lysimeter Studies
AMBIO: A Journal of the Human Environment, 2018Co-Authors: Holger Rupp, Ralph Meissner, Peter LeinweberAbstract:This study aimed to demonstrate the impact of phosphorus (P) mineral fertilization on topsoil P content and P leaching. We evaluated 83 datasets from 25 years from Lysimeter experiments involving different cropping systems (winter crop, summer crop and autumn tillage, harvested grass) or unfertilized fallow, four types of soil texture, and three levels of applied mineral P fertilizer. A positive monotonic and significant correlation was indicated between P in the topsoil determined by the double lactate method (P DL) and the yearly flow-weight total (TP) concentrations in leachates with Spearman rank correlations r s (r s > 0.183) and probability (p) < 0.05. The present German recommended rates of P mineral fertilization are proposed insufficient to protect fresh and marine waters from undesired P pollution and eutrophication. A long-term reduction of excess soil P is urgent along with other measures to mitigate high P inputs to surface and ground waters.
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Estimating the effects of set‐aside on water quality: scaling‐up of Lysimeter Studies
Land Degradation & Development, 1999Co-Authors: Ralph Meissner, Joe Seeger, Holger Rupp, P SchonertAbstract:Since 1990, agriculture in the five new federal states of Germany has experienced a fundamental structural change. As much as 10 per cent of the 6·2 million ha of previously intensively farmed agricultural land were set-aside abruptly. In the spring of 1991, a Lysimeter trial (filled with soils common in the catchment area of the Elbe River), was set up to investigate the impact of set-aside on the water and solute balance. The Studies proved that restricting agricultural use in areas previously farmed intensively by converting them into permanent or rotation fallow will result in measurable changes in deep percolation (ground-water recharge) and water quality in less than one year. The results of the Lysimeter Studies were extrapolated to calculate the effects of set-aside in a catchment area (about 2 500 ha) with similar meteorological and soil conditions. The calculations showed that increasing the area under rotation fallow from 8 to 15 per cent increases the nitrogen load of the stream draining the catchment by about 5 per cent. Copyright © 1999 John Wiley & Sons, Ltd.
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estimating the effects of set aside on water quality scaling up of Lysimeter Studies
Land Degradation & Development, 1999Co-Authors: Ralph Meissner, Joe Seeger, Holger Rupp, P SchonertAbstract:Since 1990, agriculture in the five new federal states of Germany has experienced a fundamental structural change. As much as 10 per cent of the 6·2 million ha of previously intensively farmed agricultural land were set-aside abruptly. In the spring of 1991, a Lysimeter trial (filled with soils common in the catchment area of the Elbe River), was set up to investigate the impact of set-aside on the water and solute balance. The Studies proved that restricting agricultural use in areas previously farmed intensively by converting them into permanent or rotation fallow will result in measurable changes in deep percolation (ground-water recharge) and water quality in less than one year. The results of the Lysimeter Studies were extrapolated to calculate the effects of set-aside in a catchment area (about 2 500 ha) with similar meteorological and soil conditions. The calculations showed that increasing the area under rotation fallow from 8 to 15 per cent increases the nitrogen load of the stream draining the catchment by about 5 per cent. Copyright © 1999 John Wiley & Sons, Ltd.
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Lysimeter Studies in East Germany concerning the influence of set aside of intensively farmed land on the seepage water quality
Agriculture Ecosystems & Environment, 1998Co-Authors: Ralph Meissner, Joe Seeger, Holger RuppAbstract:Abstract Since 1990, the five new federal states of Germany have experienced a fundamental structural change in agriculture. As much as 10% of the 6.2 million hectares of the previously intensively farmed agricultural areas were abruptly set aside. In the spring of 1991, a Lysimeter test, designed in 1983 to maximize yields, was adapted to these new agricultural conditions. The purpose of the test was to investigate the impact of the structural changes on water balance and budget of materials. Leaching of relevant cations (Ca 2+ , Mg 2+ , Na + , and K + ) and anions (total PO 4 3− , NO 3 − , Cl − , and SO 4 2− ) contained in the seepage water as well as the resulting pH-values were determined for various types of set aside. The reference treatment consisted of intensively farmed Lysimeters following the principles of BMP (best management practices). The tests covered a period of three years. The Studies proved that restricting agricultural usage on areas previously farmed heavily, by converting them into permanent or rotation fallow, will result in measurable changes of seepage water recharge and quality within less than one year. The permanent fallow showed large leaching losses of the measured cations even three years after set aside. In contrast, the leaching of the measured anions NO 3 − , SO 4 2− and Cl − decreased significantly compared with the initial level. If cation leaching decreases from lack of additional supply, a shift of the pH into the acid range is to be expected. A one year set aside in the form of a rotation fallow is connected with increased leaching of nitrate. Compared with intensively farmed agricultural land, nitrate leaching in the year of set aside is increased by approximately 55% and in the year of resuming intensive agricultural production by 30%.
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influence of mineral fertilizers and different soil types on nutrient leaching results of Lysimeter Studies in east germany
Land Degradation & Development, 1995Co-Authors: Ralph Meissner, Holger Rupp, J Seeger, P SchonertAbstract:A Lysimeter experiment on mineral fertilizer use and soil type was begun in 1985 to study the interrelationships between the level of mineral fertilization and the leaching of nutrients. Increased application of mineral fertilizers brought about not only a significant reduction in effluence build-up, but also a significant increase in yield. The lowest levels of nitrogen leaching were found in clay-sand soil in use as grassland, and the highest in sandy soil used as arable land. Unexpectedly, the study was unable to prove statistically that a reduction in N, P and K leaching follows automatically from a reduction in mineral fertilization. Hence, suboptimal fertilization cannot be the only corrective measure if a noticeable or marked reduction in the adverse impact on water quality due to nutrient leaching is to be achieved. Interim plantings should be integrated in crop rotations. Agricultural crops must be siteadapted and suited to the fertilization regime.
Bernhard Gottesburen - One of the best experts on this subject based on the ideXlab platform.
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local and global inverse modelling strategies to estimate parameters for pesticide leaching from Lysimeter Studies
Pest Management Science, 2015Co-Authors: Gunnar M Kahl, Yury Sidorenko, Bernhard GottesburenAbstract:BACKGROUND As an option for higher-tier leaching assessment of pesticides in Europe according to FOCUS, pesticide properties can be estimated from Lysimeter Studies by inversely fitting parameter values (substance half-life DT50 and sorption coefficient to organic matter kom). The aim of the study was to identify adequate methods for inverse modelling. RESULTS Model parameters for the PEARL (Pesticide Emission Assessment at Regional and Local scales) model were estimated with different inverse optimisation algorithms – the Levenberg–Marquardt (LM), PD_MS2 (PEST Driver Multiple Starting Points 2) and SCEM (Shuffled Complex Evolution Metropolis) algorithms. Optimisation of crop factors and hydraulic properties was found to be an ill-posed problem, and all algorithms failed to identify reliable global minima for the hydrological parameters. All algorithms performed equally well in estimating pesticide sorption and degradation parameters. SCEM was in most cases the only algorithm that reliably calculated uncertainties. CONCLUSION The most reliable approach for finding the best parameter set in the stepwise approach of optimising evapotranspiration, soil hydrology and pesticide parameters was to run only SCEM or a combined approach with more than one algorithm using the best fit of each step for further processing. PD_MS2 was well suited to a quick parameter search. The linear parameter uncertainty intervals estimated by LM and PD_MS2 were usually larger than by the non-linear method used by SCEM. With the suggested methods, parameter optimisation, together with reliable estimation of uncertainties, is possible also for relatively complex systems. © 2014 Society of Chemical Industry
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Comparison of Lysimeter Results and Leaching Model Calculations for Regulatory Risk Assessment
Journal fur Verbraucherschutz und Lebensmittelsicherheit-Journal of Consumer, 2008Co-Authors: Ian Hardy, Bernhard Gottesburen, A. Huber, B. Jene, G. Reinken, Herbert ResselerAbstract:Experimental results from 34 outdoor Lysimeter Studies have been compared with leaching model simulations in order to evaluate their role in the tiered regulatory decision making scheme for the protection of groundwater. 63 compounds (28 active substances and 35 metabolites) were evaluated, resulting in a total of 73 model/Lysimeter comparisons.
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validation of the pesticide leaching model pelmo using Lysimeter Studies performed for registration
Chemosphere, 1997Co-Authors: M Klein, Bernhard Gottesburen, Martin Muller, Martin Dust, Gerhard Gorlitz, Jan Hassink, Regina Kloskowski, Roland Kubiak, Herbert Resseler, Helmut SchaferAbstract:The performance of simulation models to predict the amount of leached water, pesticide concentrations in soil and pesticide concentrations in the leachate from 39 Lysimeters columns with undisturbed soil cores is described in this paper. The behaviour of 14 pesticides plus 1 metabolite was investigated mainly on loamy sand soils at four different locations in Germany. In three Lysimeter Studies a silty loam soil was used. The annual amount of precipitation ranged from 706 mm to 1393 mm (rainfall plus additional irrigation), 85 % of the experiments received a minimum precipitation of 800 mm. The Koc values of the pesticides were between 5 and 4000, the mean DT50 values in soil ranged from 5 to 120 days. The model calculations were performed with three different computer models: PRZM-1, PELMO 1.5 and PELMO 2.0. The model PELMO 2.0 predicted amounts of cumulated leachate with a mean absolute deviation of 134 mm (relative deviation factor of 1.37) more exactly than PRZM-1 (absolute value 194 mm, relative value 1.59) and PELMO 1.5 (absolute value 205 mm, relative value 1.51). The mean variability within the replicates of the Lysimeter collective was absolute 66 mm (relative factor of 1.14) over the two years period of the experiments. PELMO 2.0 predicted the amounts of cumulated leachate from the Lysimeters with good accuracy, PRZM-1 was less precise, probably because crop specific scenarios were not included in this model. A statistical analysis showed that the amount of cumulated leachate depends on climatic parameters and on the production of biomass. Both models showed a slight tendency to underestimate residues in soil. PELMO 2.0 predictions of the mean annual pesticide concentrations in the leachate differed absolutely by 0.02 μg/L and relatively by a factor of 1.5. PRZM-1 predictions showed an absolute deviation of 0.01 μg/L and a relative one of a factor of 1.7 from the Lysimeters. The variability within the Lysimeter collective itself was 0.02 μg/L (relative value of 1.3). The 90 percentile of PELMO 2.0 predictions differed absolutely by 0.08 μg/L (relative factor of 6.4) and PRZM-1 predictions by 0.05 gg/L (relative 7.9) for the Lysimeters. The variability within the Lysimeter collective was absolute 0.08 μg/L (relative for a factor of 3.1). 90 % of the PELMO 2.0 and PRZM-1 simulations had a maximum deviation of not more than a factor of 10 (one order of magnitude) from the measured results. The variability within the Lysimeter collective was in the same order of magnitude as the deviation of the model predictions from the mean of the Lysimeter 90 percentile. Pesticides were measured in 30 % of the Lysimeters, 2 % showed a mean annual concentration above 0.1 gg/L. From the agreement of observed and predicted values and the variability within these data groups it can be concluded that PELMO 2.0 is appropriate to predict leachate volumes and concentrations of pesticides in leachate water and to assess the leaching potential of pesticides for regulatory purposes within the aove mentioned ranges and limits and for the environmental conditions of the Studies evaluated.
John Stenstrom - One of the best experts on this subject based on the ideXlab platform.
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laboratory and Lysimeter Studies of glyphosate and aminomethylphosphonic acid in a sand and a clay soil
Journal of Environmental Quality, 2011Co-Authors: Lars Bergstrom, Elisabet Borjesson, John StenstromAbstract:98 Due to the increasing concern about the appearance of glyphosate [N-(phosphonomethyl)glycine] and its major metabolite aminomethylphosphonic acid (AMPA) in natural waters, batch laboratory and Lysimeter transport Studies were performed to assess the potential for leaching of the compounds in two agricultural soils. Unlabeled and 14C-labeled glyphosate were added at a rate corresponding to 1.54 kg a.i. ha−1 on undisturbed sand and clay columns. Leachate was sampled weekly during a period of 748 d for analyses of glyphosate, AMPA, total 14C, and particle-bound residues. Topsoil and subsoil samples were used for determination of glyphosate adsorption, glyphosate degradation, and formation of AMPA and its degradation. Th e infl uence of adsorption on glyphosate degradation was confi rmed, giving very slow degradation rate in the clay soil (half-life 110–151 d). Th e kinetics of AMPA residues suggest that although AMPA is always more persistent than glyphosate when formed from glyphosate, its degradation rate can be faster than that of glyphosate. Th e kinetics also suggest that apart from glyphosate being transformed to AMPA, the sarcosine pathway can be just as signifi cant. Th e long persistence of glyphosate was also confi rmed in the Lysimeter study, where glyphosate+AMPA residues constituted 59% of the initial amount of glyphosate added to the clay soil 748 d after application. Despite large amounts of precipitation in the autumn and winter after application, however, these residues were mainly located in the topsoil, and only 0.009 and 0.019% of the initial amount of glyphosate added leached during the whole study period in the sand and clay, respectively. No leaching of AMPA occurred in the sand, whereas 0.03 g ha−1 leached in the clay soil. Laboratory and Lysimeter Studies of Glyphosate and Aminomethylphosphonic Acid in a Sand and a Clay Soil
