Migration Of Herbicides In Soil Under Irrigation Conditions

With the development of agriculture,herbicides have become an effective means and necessary measure for the control of weeds in agricultural production.Herbicides increase the yield and income of crops,and due to their physicochemical properties,pharmaceutical technology quality and other issues to human life safety and The living environment has brought about negative effects that cannot be ignored.Therefore,studying the migration behavior of imazethapyr in soil has guiding significance for the field application and the control of non~point source pollution.In this paper,the distribution of imazethapyr in soil was studied by the simulation of the outdoor migration of herbicides in soil and the leaching test combined with HPLC instrumentation.The migration of imazapyr niacin in cultivated land was explored through an outdoor field simulated irrigation experiment.The main results were studied.as follows:In this paper,the experiment was conducted in a field plot with 8 plots of length and width of 8 m × 1 m.Two plots of 10° and 15° were used.At a given flow rate,two total irrigation volumes,20 L and 60 L,and 2 repetitions were used.The concentration of herbicides in the soil samples of 0~10cm,10~20cm and 20~30cm soil layers on the slope,in the slope,and under the slope was observed to analyze the temporal and spatial migration characteristics of the herbicide imazethapyr in the soil.The main research results are as follows::(1)The leaching characteristics of the herbicide imazethapyr in soil were clarified:At the seedling stage,flowering and fruiting bud differentiation stage of herbicide concentration of total irrigation 60 L increasing trend slope is greater than the total amount of irrigation 20 L increasing trend,i.e.,increases the total amount of irrigation,imazethapyr slope changes significantly with the migration.Under the same conditions the slope,the greater the total amount of irrigation,imazethapyr more prone to migrate downslope,on the same slope,herbicides surface migration occurs along the slope,the cumulative amount of imazethapyr increases with decreasing slope.(2)Imazethapyr come to migrate along the slope of the characteristic:At the seedling stage,flowering and fruiting bud differentiation stage of herbicide concentration of total irrigation 60 L increasing trend slope is greater than the total amount of irrigation 20 L increasing trend,i.e.,increases the total amount of irrigation,imazethapyr slope changes significantly with the migration.Under the same conditions the slope,the greater the total amount of irrigation,imazethapyr more prone to migrate downslope,on the same slope,herbicides surface migration occurs along the slope,the cumulative amount of imazethapyr increases with decreasing slope.(3)Clearly the migration characteristics of imazethapyr in soil:Under certain conditions the total amount of irrigation,the entire growth period in the 0 ~ 10 cm 10 ~ 20 cm of soil and soil imazethapyr cumulant declining trend,the downward trend of the slope is greater than 15 ° 10 ° slope decline,20 ~ 30 cm in the soil,the entire amount of the accumulated rendering rising trend,the total amount of irrigation under the same conditions,the greater the slope,imazethapyr more obvious infiltration,flowering pod maturity of the particles and the drum,the maximum value of the accumulated amount in each cell imazethapyr occurred at 20 ~ 30 cm soil.(4)Determining the distribution of herbicide throughout the growing period:The maximum detectable content of imazethapyr was observed in the seedling stage on a 10° slope with a 20 L irrigation volume.The maximum detection content was 19.44 μg/L.The total amount of irrigation at the seedling stage was 60 L on a 15° slope with a minimum value of 4.84 μg/L..In the case of the same gradient and different amount of irrigation water,the longitudinal infiltration behavior was greater than the migration along the slope;in the case of the same amount of irrigation and different gradients,the larger the gradient,the more the imidazole acetic acid migrated,and the overall distribution of imazethapyr on the slope surface.The situation is that the cumulative amount in the lower segment is greater than the cumulative amount in the upper segment,and the cumulative amount in the deep soil is generally greater than the residual amount in the soil surface.