Study On The Fate Of Fomesafen In The Environment

With the development of agriculture, herbicide has become effective means and measures of prevention and control of weeds in agricultural production. The crop yield while guaranteeing the herbicide, because the physicochemical properties of its own technology, quality problems of pharmaceutical, environmental influences degree brought huge negative effect on the safety of life and living environment human. Fomesafen is a long residual herbicide, because of high efficacy and low toxicity in mammals and fish and shellfish and other advantages, and is widely applied to control broadleaf weeds in soybean fields. But with the increasing the frequency of use and the increase of dose, and the weather co nditions are not conducive to the degradation and other factors, the large number of fomesafen residues in soil the grass ether of after crop phytotoxicity, seriously affect the reasonable adjustment of plantin g structure. In addition, fomesafen can through a variety of ways into the environment, pollute the atmosphere, soil, water ring Environment, the harm to non target organisms, so the study of the behavior of the behavior of the soil in the field of fluoride in the field has a guiding significance.The soil herbicide leaching simulation test device combined with HPLC instrument analysis method is used to study the distribution of fomesafen in soil, and through the method of instrument analysis and experiment of the leaching of different environmental co nditions of fomesafen, degradation effect, main research results are as follows:(1)To establish a method for detecting herbicide in soil profile(patent pending). The patented method for detecting the fomesafen in soil horizontal and vertical distribution.(2)The results showed that the vertical distribution: fomesafen leaching in soils with depth, fomesafen concentration becomes low, the soil depth fomesafen detected concentration 25 cm 6.91 mg·kg-1, exceeding 30 cm of soil when fomesafen detected concent ration 0 mg·kg-1, leaching depth depth of 25-30 cm.The lateral distribution showed that: in the same plane soil, leaching agents distributed points of differences, along with soil depth, pharmaceutical distribution differences became smaller, more uniform distribution; adding additives also affect fomesafen in soil leachin g distribution, and the impact of significant differences between different additives, which adds new silicone additives uniform Ly fomesafen lateral distribution of the most significant.(3)When adding different concentrations of fomesafen, the greater the concentration, the stronger soil leaching, high doses of 150 mg·kg-1 leaching depth maximum kg, up to 30-35 cm; the higher soil water content, the faster the leaching of soil containing when up to 20% water, soil leaching maximum depth of more than 35 cm; the greater rainfall, soil permeability enhancement capability stronger, the deeper the depth of leaching, when the same time as high as 140 mm rainfall, soil leaching maximum depth of m ore than 35 cm.(4)Leaching soil organic matter content is higher, the more difficult the agent down with the rain, the more shallow leaching, when the soil organic matter content of up to 7.4 %, leaching depth of 20-25 cm;leaching columns were added to the surface of fom esafen agent(SL), emulsifiable concentrates(EC) and microemulsion(ME) at three different pharmaceutical formulations, leaching distribution is different, the results show a large water-soluble agent showed strong leaching characteristics.(5) Fomesafen tested soil degradation followed in a kinetic equation, there are differences of different concentrations fomesafen degradation rate, degradation rate size: 100 mg·kg-1> 50 mg·kg-1> 150 mg·kg-1, respectively, for the half-life 86.64 days, 100.45 days, 119.5 days.(6)The rate of degradation and soil temperature fomesafen, and soil organic matter content, soil moisture was positively correlated, when the soil water holding capacity from 5 % to 20 %, the degradation rate gradually accelerated; moreover degradation rat e also varies with temperature rise gradually speed up, when the temperature is 35 ℃, fomesafen fastest degradation rate; high organic matter content of the soil is conducive to enhancing the role of fomesafen degradation of organic matter content of 5.5 % degradation fastest.(7)The degradation rate fomesafen and soil p H was negatively correlated with the increase of the rate of degradation of soil p H value decreases in acidic soil p H =5, the fastest degradation.(8)The effects of different water conditions on fomesafen Degradation. The results show that: the degradation rate fomesafen and water temperature positive correlation, fomesafen degradation rate also increases with the temperature gradually accelerated when the temperature is 35℃, fomesafen degradation fastest; when the test water to the river, groundwater, tap water, fomesafen degradation rate is different degradation rates in the river fastest in tap water slowest; inversely proportional to the rate of degradation and the p H of the water, with the p H value of the water body for the test of but increased to reduce the rate of degradation in the acidic water p H = 5:00 degradation of the fastest.