新农药单甲脒在植物－土壤系统中的生态效应（以棉花为例）

该文研究了新农药单甲脒对植物－土壤系统的生态影响，结果认为：所设置的６个浓度（对照、２５％单甲脒水剂稀释１５００倍、１０００倍、８００倍、５００倍、１００倍）对棉花虫害有不同程度的防治效果，以１００倍最好，可防治棉花多种虫害。单甲脒对棉花种群的结构与功能无不良影响。高浓度单甲脒从８００倍起至５００倍可使叶片气孔缩小，减少蒸腾速率，从而降低对水分的消耗，促进光合产物的形成，因而光合速率增长，生物量提高。单甲脒在棉花叶片和根系及土壤都有少量积累，且随浓度增加而呈上升的趋势，以１００倍的叶子积累明显为５．０３ｍｇ／ｋｇ，其余都在０．７ｍｇ／ｋｇ以下；在土壤仅１００倍的表土有少量积累为０．８１ｍｇ／ｋｇ。单甲脒可提高植物Ｎ、Ｐ含量和土壤Ｎ含量，对土壤其他性状指标影响不明显。初步认为：本试验所设置的浓度超过５００倍以上的处理不会对植物和土壤造成污染。

THE ECOLOGICAL EFFECT OF NWE PESTICIDE MONOCARBOXOLDEHYDE IN PLANT-SOIL SYSTEM

his article has studied the ecological effect of new pesticite monocarboxoldehyde(DMAH)to the plant-soil system,The results show that the siw treated concentrations(CK.25%.DMAH diluted by 1500,1000,800.500,100 times)have different degress of preventionand control effect to cotton insect pest. The 100 times dilution is the best. which can preventmany kinds of cotton insect pest.DMAH has no bad effect on structure and function of thecotton population.The high concentraction DMAH(800 times to 500 times)can make the leafstomata narrow and reduce the transpiration rate,thus reducing the consume of the moistureand promoting the formation of the photosynthesis prodtict.thus increasing photosynthesisrate and biomass.There is a little DMAH accumulation in the cotton leaf and root, and it as-sumes a rising trend as the concentration rising.The accmulation of the 100 times obviously1s 5.05mg/kg,the others are below 0.7mg/kg.There is a little accumulation(0.81mg/kg)inthe surface soil which concentration is 100 times.DMAH can increase the contents of N,P inplants,and increase the content of N in soil.DMAH has no obvious effect on other propertyindexes of soil.Preliminaryly.We can conclude that the treated concentrations exceeding 500time installed in this tial do not pollute plants and soil.