我国棉田生态系统立体污染及其防治对策

棉花的农药、化肥和地膜使用量在我国主要农作物中均占据首位且居高不下,棉田生态系统受到从水体、土壤、生物到大气的交叉性“立体污染”。农膜的大量使用及高残留破坏土壤结构,影响土壤的透气性,并导致土壤质量下降;同时残膜降解过程中产生的有毒物质,阻碍种子根系生长,影响产量;过量施用化学肥料加之施用方法不妥,导致了严重的生态环境污染并危及人类健康;棉花病虫害防治高度依赖高毒、剧毒化学农药,导致药害,天敌和有益生物遭受毁灭性杀伤。农药、化肥成份残留于土壤中,或者被无节制地排放到水体环境,或随意散逸到大气中。从四个角度提出了相应的综合防治对策。对污染源头实施技术性控制。从生态系统平衡化和植物营养利用最优化着手,研究组建我国三大棉区棉田生态型IPM技术体系,形成棉田病虫害防治技术标准及棉田平衡施肥技术标准。改进施药施肥方法,创新棉花栽培和耕作措施,研制可降解环保棉田专用农膜。建立棉田生态系统污染修复技术体系。大力发展生物技术,提高生物防治水平。

Study of Agricultural Tri-dimension Pollution on Ecological System in Cotton Field and Its Control Tactics

Cotton stands first constantly in the using of pesticide,fertilizer and plastic film comparing to the other crops in China.Presently,the negative effects have emerged severely and have been embodied in the agricultural tri-dimension pollution(ATriP) from water,soil and organism to the air in the ecological system in cotton field.This paper firstly analyzed three key factors of ATriP of ecological system in cotton field and summarized the present situation of the AtriP.First,plastic film remained in the soil largely.These remnants destroyed the soil structure,blocked the ventilation and thus resulted in the bad soil quality.Meanwhile,during the decomposition,these remnants produced poisonous matters and then inhibited the root growth and reduced production.Secondly,while the over-fertilization and the incorrect ways led to the seriously ecological environment pollution and endangering human health badly.Thirdly,the controls of diseases,pests and weeds in cotton crop were highly depended on pesticide of strong toxicity.On one hand,it was liable to arouse the pesticide scathe;on the other hand,some natural enemies of pests were subjected to fatal poison during the malign recycle of anti-pesticide and increasing using quantity and toxicity of pesticide.Consequently,it broke the ecological balance.Especially,the lower utilization and misuse of pesticide and fertilizer have made poisonous matters remain in the soil,released into water environment or escaped into the atmosphere.These poisonous remnants certainly contributed to the ATriP from water,soil to the air after long time of accumulation and cooperation,and accordingly had deep effects on the crop quality,world climate and human health.On the basis of AtriP states in the ecological system of cotton field,we put forward the corresponding control tactics from four aspects.First is to control the source of AtriP by means of effective techniques,and constitute IPM technology system so as to reduce the chemical control and to realize the balanceable fertilization.Second is to found an AtriP-preventing technology system by way of researching and generalizing environment-friendly pesticide and slow-releasing fertilizer and improving the means of applying pesticide and fertilization;establishing an environment-friendly and efficient planting and cultivation measures;developing a type of biomaterial and decomposable multi-function agricultural membrane.Third is to found an AtriP-renovating technology system.A quick-diagnosis information database should be established firstly based on the AtriP distribution situation and the AtriP mechanism.Researches should be intensified to realize the bio-decomposition or bio-elimination of the plastic membrane remainders and poisonous remnants of pesticide and fertilizer.As to the transgenic insect-resistant cotton,it is necessary to set up a technology norm for detecting and monitoring the remaining and decomposition regularly.The last tactic is to cultivate new varieties of high quality and multiple fastnesses,such as insect-resistance,disease-resistance,drought-resistance,salt and alkali-tolerance and high fertilizer-efficiency by biotechnology so that we can elevate the bio-control level in the cotton field.