氮素对香根草吸收和去除扑草净的影响

Effects of Nitrogen on Vetiveria zizanioides Absorbing and Removal of Prometryn

以香根草为研究对象,通过温室培育、样本试验和室内分析,研究了高浓度氮含量(0.49mg/L)、中浓度氮含量(0.33 mg/L)、低浓度氮含量(0.16 mg/L)3种浓度氮素水平条件下,香根草对单子叶营养液中扑草净的吸收、去除效果。结果表明:氮素能显著提高香根草根系对单子叶溶液中扑草净的吸收,同时能促进扑草净在根系与茎叶之间的转移;中浓度氮素为水平时,扑草净在溶液中的残留率最小为1.80%,此时香根草对扑草净的去除率最大为18.07%。试验第40天时,氮浓度为低浓度水平时,扑草净在溶液中的残留率为1.86%,香根草对扑草净的去除率为16.51%;试验第40天时,与高浓度氮水平相比,中低浓度氮水平条件下,香根草表现出更佳的生长态势,且对溶液中扑草净的吸收、去除效果更好。

With Vetiveria zizanioides as the research object, through greenhouse cultivation, sample testing and laboratory analysis, the absorption and removal effects of V. zizanioides on monocotyledonous nutrition was studied under the conditions of high concentration of nitrogen （0. 49 mg/L）, medium concentration of nitrogen （0. 33 mg/L） and low concentration of nitrogen （0. 16 mg/L）. Results showed that nitrogen could significantly improve the absorp- tion of V. zizanioides root system on prometryn in monocotyledon nutrient solution. Meanwhile, it promoted transfer of prometryn between the root system and stem leaves. When nitrogen concentration level was medium, the mini- mum residual rate of prometryn in the solution was 1.80%. The maximum removal rate of V. zizanioides on prome- tryn was 18.07%. When the nitrogen concentration level was low at the 40th day of test, the residual rate of prome- tryn in the solution was 1.86%. The removal rate of V. zizanioides on prometryn was 16.51%. V. zizanioides showed better growth trend under medium and low nitrogen levels compared with that at high concentration nitrogen level at the 40th day of test. In addition, it had better absorption and removal effect on prometryn in monocotyledon nutrient solution.