草甘膦对大豆田土壤养分及其功能酶活性的影响

Effect of Glyphosate on Soil Nutrient and the Functional Enzyme Activities in Soybean Fields

为探究草甘膦对大豆田土壤养分及其功能酶活性的影响,以转基因抗草甘膦大豆呼交06-698为材料,采用田间试验方法,研究了1.2、2.4、3.6 kg·hm^(-2)草甘膦对大豆田土壤氮(N)、磷(P)、钾(K)及其功能酶活性的影响。2年试验结果均表明,在草甘膦2.4 kg·hm^(-2)和3.6 kg·hm^(-2)用量下,大豆田土壤碱解氮含量、速效磷含量、脲酶、纤维素酶、磷酸酶和根瘤固氮酶活性显著降低,降低峰值分别为10.57%、11.30%、67.66%、40.62%、45.88%和74.49%,过氧化氢酶活性显著升高,2年间的升高峰值为131.93%,速效钾含量不受草甘膦影响。这种影响随草甘膦施用后时间延长而逐步恢复正常,长时间不会对土壤养分及其功能酶活性带来不利影响。通过主成分与综合评价方法分析,草甘膦用量为2.4和3.6 kg·hm^(-2)时,以土壤N、P、K养分及其功能酶活性为主成分的土壤质量均高于CK。研究结果可为农田生态系统可持续利用和转基因抗草甘膦大豆商业化种植提供理论依据。

To investigate the effects of glyphosate on soil nutrients and the functional enzyme activities in soybean fields,this paper investigated the effect of 1.2,2.4 and 3.6 kg·hm^(-2) of glyphosate on soil nitrogen(N),phosphorus(P),potassium(K)and the functional enzyme activities in soybean fields using a field experiment with transgenic glyphosate-resistant soybean Hujiao 06-698 as material.The results of 2 years of trials showed that the content of soil alkaline nitrogen and available phosphorus,and the enzyme activities of urease,cellulase,phosphatase and nodule nitrogenase activities were significantly reduced with peaks of 10.57%,11.30%,67.66%,40.62%,45.88%and 74.49%,respectively,and catalase activity was significantly increased with peaks of 131.93%in the two years in soybean fields at 2.4 kg·hm^(-2) and 3.6 kg·hm^(-2) of glyphosate use rate,while available potassium content was not affected by glyphosate.However,this effect gradually returned to normal with time the extension of time after glyphosate application and did not bring adverse effect on soil nutrients and the functional enzyme activities for a long time.The soil quality analyzed by principal component and integrated evaluation methods with soil N,P and K nutrients and the functional enzyme activities as the main components was higher than that of CK at 2.4 kg·hm^(-2) and 3.6 kg·hm^(-2) of glyphosate use rate.The results of the research can provide a theoretical basis for sustainable utilization of farmland ecosystem and commercial planting of transgenic glyphosate-resistant soybeans.