关键词: 地膜污染, 回收率, 农户, 张掖市

Abstract: Plastic film mulching plays an important role in China’s increasing agricultural production due to its soil warming and moisture conservation effects. According to China Agricultural Statistical Yearbook 2014, the volume of plastic film mulch used in China increased to 136.2×10⁴ t in 2013, and the total crop area covered with plastic film mulch similarly increased to 1 765.7×10⁴ hm². Now, China ranks the top in the world in terms of the use of plastic film mulch. While producing huge benefits, plastic film mulch technology has also brought on a series of pollution hazards.
In order to investigate the status quo of mulch residue, a detailed household survey in the oasis area of the Heihe River Basin, China, was conducted by the authors with the help of Hexi University in July, 2014, and 131 valid questionnaires were obtained. A Probit model and a multi-variable regression model were built to understand the influencing factors of mulch recycling rate.
Based on the survey data and regression models, some conclusions about plastic film residue and the factors affecting farmers’ willingness of film recycling were obtained. Firstly, agricultural plastic film mulching is widely used for almost all crops in Zhangye. The crop area covered with plastic film mulch accounted for 69.9% of the total in 2014. Secondly, the rate of residual film in Zhangye was 25.7% on average in 2014, and the amount of residual film in Zhangye in 2014 reached 63.75 kg/hm², equal to the amount of plastic film applied on the corn field in this area. The level of residual agricultural film is obviously higher than the level in Inner Mongolia region and the North China, nearly reaching the limit of national standard. Although plastic film can increase soil temperature and conserve moisture, corn covered with plastic film mulch still cannot cope with low temperature and less water in the hilly regions of Zhangye. So farmers in the counties of Shandan and Minle prefer to plant wheat and barley rather than plant corn. The height limit of film application is about 2 100 m.
In the plain region of the middle reach of the Heihe River, higher wage has a negative impact on the rate of film recycling. Higher wages reduce the dependence of farmers on agricultural income and increase the opportunity cost of farming. Farmers are unwilling to input more labor in the field. Farmers prefer to apply black film in vegetable fields and the recycle rate in vegetable fields is higher than that in grain fields, because vegetable can bring higher profit than grain crops and vegetable fields need higher soil quality. More plots mean more commuting time. So farmers with more plots usually manage their lands extensively, which caused the low recycling rates. Agricultural labor input and the elevation of farmer’s houses have positive impacts on the rate of film recycling. It is worth noting that the educational level of the household head and agricultural subsidy have no impacts on the recycling rate of agricultural film.
The policy implications are as follows: 1) the quality of plastic film should be improved obviously so that it can be easily picked up; 2) the development of plastic film recycling machine should be sped up in order to reduce the increasing labor cost; and 3) research and development of biodegradable mulch film should also be improved

Key words: farmer, plastic film pollution, residual rate of film, Zhangye City