草甘膦对枳根际土壤有机酸、酶活性及根际微生物的影响

为了研究草甘膦对枳根际土壤环境的影响，以枳幼苗为试材，利用含有不同剂量草甘膦的土壤种植枳幼苗，培养4个月后对不同处理的枳幼苗生长情况以及根际土壤中的有机酸含量、土壤酶活性和微生物数量进行比较。结果表明：在5 mg/kg的草甘膦条件下，枳苗生长、根际土壤酶活性以及细菌生物量没有受到明显影响。随着草甘膦剂量递增，根际土壤中草酸与琥珀酸含量以及真菌生物量呈现先增后减的趋势。在高剂量草甘膦（20 mg/kg）处理中，枳苗的株高、茎粗、叶干重、茎干重、主根长、总根长、总表面积、总根尖数、根干重和根系活力均会显著降低，根际土壤中草酸、琥珀酸、丙二酸和柠檬酸含量显著减少，根际土壤中的过氧化氢酶、脲酶、转化酶和酸性磷酸酶活性显著下降，根际土壤细菌和真菌生长也明显受到抑制。

Effects of glyphosate on organic acids, enzyme activities and microorganisms in rhizosphere soil of Poncirus trifoliata

In order to investigate the effects of glyphosate on the rhizosphere of Poncirus trifoliata, the organic acid content, enzyme activities, and microbial biomass in rhizosphere soil, as well as seedling growth, were compared among different glyphosate treatments after four months. The results showed that the seedling growth, enzyme activities, and bacterial biomass were not significantly affected in glyphosate at 5 mg/kg. While the oxalic acid, succinic acid and fungal biomass in rhizosphere increased firstly and then decreased with the augment of glyphosate concentration. When at 20 mg/kg of glyphosate treatments, the height, stem diameter, leaf and shoot dry weight, taproot length, total root length, total surface area, total root number, root dry weight, and root activity were inhibited distinctly, and the organic acid content (oxalic acid, succinic acid, malonic acid, and citric acid), soil enzyme activities (catalase, urease, invertase and acid phosphatase), and microbial biomass (bacteria and fungi) in rhizosphere soil decreased significantly.