The Use of Plastic Mulch Film in Typical Cotton Planting Regions and the Associated Environmental Pollution

Pollution caused by residual plastic film in agricultural fields has been an important factor that is contributing to the deterioration of the agricultural environment.This study was conducted in the Yellow River Basin cotton planting area(Handan city in Hebei Province)and in the western inland cotton planting area(production and construction corps in Xinjiang Province)in 2007.The input of plastic film,recovery and pollution of residual plastic film in the study areas were evaluated by means of farmer survey and field sampling.The results showed that the input amount of plastic film varied in the different cotton planting region due to the difference of climate condition and farming system.The input amount of plastic film was 33 kg·hm-2 in Handan,but in Xinjiang it reached 61.4 kg·hm-2.There was no significantly different recovery ratio observed between both sites,but the amount of residual plastic film was quite different due to the difference of input amount.The average amount of residual plastic film in the soil(0～30 cm)was 80.5 kg·hm-2 in Handan,but in Xinjiang it was 208.5 kg·hm-2.The residual plastic film was mainly distributed in the tilled soil layer(0～20 cm)in both sites and the pollution in Xinjiang was more serious than that of Handan viewed from the depth of polluted soil layer.Most farmers had realized the pollution of plastic film,but due to the lack of a suitable technique to recove and reuse,the plastic film pollution continuesd to be a big problem in these areas,especially in Xinjiang.