The Ecological Response Of Reed Wetland System To Herbicide Of Farmland Drainage In Western Jilin Province

Agricultural non-point pollution and wetlands degradation for lack of water are two difficult problems in ecological environment. An effective way to solve these problems is to restore wetlands with the water resources of farmland drainage. However, the effect of herbicide residues from drainage on wetland system are still not clear. Understanding the behavior of herbicide and its environment risk, which is important to the ecological conservation and restoration of wetland. To provide scientific basis forthe reed wetland degradation due to lacking of waterd used irrigation return water resources, wetland ecological engineering control of agricultural non-point source pollution technology.This study combined with field simulation and indoor simulation test in Western Jilin Province saline alkali reed wetland as the research object, to carry out the effects of herbicide bensulfuron methyl and butachlor in different concentrations on wetland reed growth development and soil enzyme activity and the effects of bensulfuron methyl and butachlor treatment under different water depth on reed wetland growth development and soil enzyme activity. The main results are as follows:The results show that saline irrigated rice fields of sulfonylurea herbicides and amide herbicide application will cause the residual herbicide in farmland drainage by field investigation and sampling analysis, Yueliangpao Irrigation and Qianguo irrigation area of Jilin Province where bensulfuron methyl was detected1.76μg/L in paddy field, but butachlor residues reached 0.02 ~ 0.16μg/L.Bensulfuron methyl(0.0099g/m2, 0.0199g/m2, 0.0398g/m2) treatment of reed wetland growth and soil enzyme activity influence, To the morphological characteristics, reed plant height increment, stem diameter and dry weight were not inhibited significantly, to the physiology indexes, chlorophyll content not change significantly, the soluble sugar content was inhibited. There was no significant inhibitory effects on soil catalase, alkaline phosphatase and invertase activity. Under BSM treatment, with the water level increasing, in water depth of 10 cm, reed grew better, soil enzyme activity was stronger.Butachlor(360 g / L, 720 g / L, 1440 g / L) was added, the morphological index of the reed wetland plant height increment, stem diameter and dry weight were not significantly influenced; in terms of physiological indexes of reed, with the increase of the concentration of butachlor, the contents of chlorophyll and soluble sugar were inhibited. The soil catalase activity was inhibited, which had no significant effect on the activity of alkaline phosphatase and invertase in soil. With the increasing of water level, the growth and development of the reed and the soil enzyme activity were better in the water depth of 10 cm.In order to reveal reed wetland system responsed to herbicides of farmland drainage and scientificly evaluate ecological risk of the herbicide to reed wetland system, to carry out studies of effects of herbicide bensulfuron methyl and butachlor on wetland reed and soil enzyme activities. Bensulfuron methyl in wetland water degradated faster, under BSM treatment, wetland reed height increment, stem diameter and dry weight has no significant inhibitory effect. Reed photosynthesis did not show a significant inhibitory effect, the soluble sugar content was inhibited. In the aspect of soil enzyme activity, bensulfuron methyl on catalase, alkaline phosphatase and invertase activity had no obvious inhibitory effect. Degradation rate of butachlor in wetland water was also faster. The high growth rate, stem diameter and dry weight of the reed plants were not significantly inhibited under the treatment of butachlor. Reed photosynthesis was not affected significantly, and the soluble sugar content was inhibited. There was no significant effect of the activity of the enzyme on the catalase activity, and the alkaline phosphatase and invertase activity had no significant inhibitory effect.Combined Indoor simulation experiment and field control experiments, herbicide bensulfuron methyl and butachlor in farmland drainage did not affect physiological ecology of wetland and wetland soil enzyme activity. from this perspective, containing the herbicide, farmland drainage can be taken as effective water resource supply in Western Jilin Province to wetland degradation because of lack of water resource.