我国地膜覆盖和残留污染特点与防控技术

地膜覆盖技术已成为我国农业应用最为广泛的农艺技术之一,但同时地膜残留污染也成为影响农业可持续发展的一个重大问题,系统分析梳理地膜覆盖种植技术、地膜残留污染的特点及防控技术对于该技术合理利用具有重要意义。本文在已有工作基础上,系统分析了我国地膜覆盖种植技术应用情况、地膜残留污染特点和防治技术。结果表明,20世纪80年代以来,我国地膜用量及覆盖面积一直呈大幅度上升态势,年增长率在8%左右,1991-2011年20年间,地膜使用强度增加了3~10倍,但存在明显区域差异。总体上,北方省区的地膜使用强度大,增长幅度快。地膜覆盖应用作物也从经济作物扩大到粮食作物,应用面积最大作物依次为玉米、蔬菜、棉花、烟草和花生等。地膜覆盖技术的应用产生了巨大效益,但同时也带来了一系列污染危害。长期覆膜农田土壤中都存在程度不同的残膜污染,残留量一般在71.9~259.1 kg·hm^-2。西北地区是残膜污染最严重的地区,土壤中残膜量远远高于华北和西南地区。残留地膜大小和形态多种多样,主要有片状、蜷缩圆筒状和球状等,在土壤中呈水平、垂直和倾斜状分布。目前,我国地膜残留污染防治技术滞后,人工回收是普遍和主要的回收形式,其他防治技术如机械回收、节约型地膜应用、生物降解地膜尚未较大规模应用。当前,为防止地膜残留污染进一步加剧,急需修订完善地膜标准和加强质量监管,提高可回收性;推广节约型地膜使用技术和残膜回收技术;开展地膜覆盖技术适应性研究,促进技术合理利用。

Review of Agricultural Plastic Mulching and Its Residual Pollution and Prevention Measures In China

Agricultural plastic film mulching is one of important technologies, but the plastic film pollution has been a serious issue for agri-cultural sustainable development in China. System analysis of this technique and its residue pollution and control ways have vital practicalsignificance for rational application of agricultural plastil film. In this paper, on the basis of our previous work,agricultural plastic filmmulching, its residue pollution and control technologies were concluded. Some important conclusions were found that, the amount of plasticfilm and mulching area had kept increasing with annual increasing rate about 8% since the 80s of the 20th century. From 1991 to 2011, thedensity of plastic film utilized increased 3-10 times, but it has very sharply different spatial pattern in different province. In general, the northand west China has high value, and the increase rate is also huge in the past 20 years. The crops of utilized mulching plastic film have extendedfrom cash crops to grain crops, and the order of crop area is followed by maize, vegetable, cotton, tobacco and peanut. The main functions ofmulching plastic film are keeping soil moisture and increasing soil temperature, against weeds and insect. At the same time, its side effectsappear with continuous utilization. The main problems are residues left in soil to destroy soil structure, impress soil permeability, impede seedgermination as well as water and nutrients uptaking, and block crop root system development. It has very serious pollution for the field utilizedplastic mulching film for long term. The residual amount in soil is about 71.9-259.1 kg·hm^-2, and has sharply spatial difference. The residualamount in soil. In Northwest China, is more serious than that in North China and Southwest China. Because of difference of tillage and appli-canon ways, there are great differences on the area and shape of the plastic film piece left in soil. The main types of shapes are flaky, crispat-ural cylindric and spherality existed in soil as horizontal, vertical and incline state. In present, there are machinery harvesting technique, re-ducing plastic film mulching technique, replacing technique with biodegradable plastic film to against this pollution. For plastic film residuespollution countermeasures, it is necessary to revise the standard of plastic film and strive monitoring the quality of plastic film, improve theretrievability of plastic residue; It is also necessary to extend reducing plastic film mulching technique, harvesting techniques and increaseharvesting rate of residue; strength the adaption study and promote the rational utilization of agricultural plastic film.