Effect Of Herbicde On Weed Control,Residue Properties And Effects On The Growth Of Sunflower

With the development concept of green agriculture put forward,reducing agricultural water and soil pollution has become an important trend of agricultural development in the future.Herbicide is the largest agricultural non-point source pollution in Hangjinhouqi area of Hetao irrigation area.It has become the future development trend of local agriculture to rationally reduce the amount of herbicide application in the future to reduce agricultural pollution.In this study,sunflower was taken as the research object,and two commonly used herbicides,glyphosate(41%glyphosate isopropylamine salt solution)and Haloxyfop-P(10.8%Haloxyfop-P emulsion),were selected to set four different pesticide gradients respectively.The gradients of glyphosate were 0;180g/667m2;240g/667m2 and 360g/667m2.The gradients were set as 0,37.5g/667m2,50g/667m2 and 75g/667m2.The control efrect of herbicide on weeds was studied by field experiment.Herbicide residue characteristics in soil and groundwater;Efrects of herbicides on growth characteristics and yield of sunflower.The main research results are as follows:(1)41%glyphosate isopropylamine salt solution had better control effect on all weeds in sunflower field when applied 240g/667m2;10.8%Haloxyfop-P emulsion applied to 50g/667m2 had a better control effect on grass weeds.(2)In this paper,the determination of glyphosate in soil and groundwater by ion chromatography and high performance liquid chromatography were established.(3)Both the herbicides glyphosate and Haloxyfop-P were detected in the soil.The residues of glyphosate were distributed in 0-5cm and 5-10cm soil,and the residues of three application rates in 0-5cm soil layer within 7 days exceeded the limit of 0.5mg/kg of Glyphosate in Soil Environmental Quality Standard GB 15618-2008.There is a risk of contaminating the soil.The residual amount of the three applied doses of Haloxyfop-P is only concentrated in the soil layer of 0-5cm and 5-10cm.At present,Haloxyfop-P has not been included as a pollutant in the Soil Environmental Quality Standard of China.Residues of both herbicides were not detected in groundwater.(4)Both glyphosate and flurpyrazol degraded rapidly in soil,and both herbicides were readily degradable pesticides(t1/2<30d).The half-life of glyphosate in 0-5cm and 5-10cm soil was about 3.02 days and 6.44 days,and no glyphosate was detected in both soil layers after 35 days of application.The half-life of flurpyrazol in 0-5cm and 5-l0cm soil was about 1.30 days and 2.19 days.(5)Glyphosate and Haloxyfop-P spirit to applying amount are three kinds of sunflower plant height,stem diameter,leaf area index and yield increased significantly,by analyzing the sunflower growth index and yield,glyphosate(41%glyphosate isopropylamine salt water)recommended usage of 240g/667m2,Haloxyfop-P(10.8%Haloxyfop-P emulsion)recommended usage of 50g/667m2.