Agricultural and Environmental Science, Soil Science, University of Rostock, Justus-von-Liebig-Weg 6, 18051, Rostock, Germany.
Department of Soil System Science, Helmholtz Centre for Environmental Research, Lysimeter Station, Falkenberg 55, 39615, Altmärkische Wische, Germany.
Environ Monit Assess. 2020 Jan 21;192(2):127. doi: 10.1007/s10661-019-8045-4.
Glyphosate (GLYP), the globally most important herbicide, may have effects in various compartments of the environment such as soil and water. Although laboratory studies showed fast microbial degradation and a low leaching potential, it is often detected in various environmental compartments, but pathways are unknown. Therefore, the objective was to study GLYP leaching and transformations in a lysimeter field experiment over a study period of one hydrological year using non-radioactive C-N-GLYP labelling and maize cultivation. N and C were selectively measured using isotopic ratio mass spectrometry (IR-MS) in leachates, soil, and plant material. Additionally, HPLC coupled to tandem mass spectrometry (HPLC-MS/MS) was used for quantitation of GLYP and its main degradation product aminomethylphosphonic acid (AMPA) in different environmental compartments (leachates and soil). Results show low recoveries for GLYP (< 3%) and AMPA (< level of detection) in soil after the study period, whereas recoveries of N (11-19%) and C (23-54%) were higher. Time independent enrichment of N and C and the absence of GLYP and AMPA in leachates indicated further degradation. N was enriched in all compartments of maize plants (roots, shoots, and cobs). C was only enriched in roots. Results confirmed rapid degradation to further degradation products, e.g., NH, which plausibly was taken up as nutrient by plants. Due to the discrepancy of low GLYP and AMPA concentrations in soil, but higher values for N and C after the study period, it cannot be excluded that non-extractable residues of GLYP remained and accumulated in soil.
草甘膦（GLYP）是全球最重要的除草剂之一，可能对土壤和水等环境各部分产生影响。尽管实验室研究表明其具有快速的微生物降解和低淋溶潜力，但它经常在各种环境部分被检测到，但途径尚不清楚。因此，本研究的目的是在一个水文学年的 lysimeter 田间试验中，使用非放射性 C-N-GLYP 标记和玉米种植来研究草甘膦的淋溶和转化。在淋出液、土壤和植物材料中使用同位素比质谱（IR-MS）选择性测量 N 和 C。此外，还使用高效液相色谱-串联质谱（HPLC-MS/MS）定量不同环境部分（淋出液和土壤）中的草甘膦及其主要降解产物氨甲基膦酸（AMPA）。结果表明，研究结束后，土壤中草甘膦（<3%）和 AMPA（<检测限）的回收率较低，而 N（11-19%）和 C（23-54%）的回收率较高。N 和 C 的时间独立富集以及淋出液中没有草甘膦和 AMPA 表明进一步降解。N 在玉米植株的所有部位（根、茎和玉米穗）中都有富集。C 仅在根部富集。结果证实了快速降解为进一步的降解产物，例如 NH，这很可能被植物作为养分吸收。由于研究结束后土壤中草甘膦和 AMPA 浓度较低，但 N 和 C 值较高，因此不能排除非可提取的草甘膦残留并在土壤中积累。
