| Change of temperature,moisture,nutrient,biological characteristic,salinity and nitrate content in soil was studied under cultivation with plastic film mulching and no film covering.The results showed that daily average temperature of soil with plastic mulching was higher than that without film covering in growth prophase of maize.The degree of enhancing temperature in 5,10,15,20 cm and 25 cm soil layers was 2.4℃、3.0℃、2.9℃、2.2℃ and 2.7℃ respectively.In June and July,daily average temperature of soil with film mulching was lower than that without film covering.The degree of dropping temperature in 5,10,15,20 cm and 25 cm soil layers was 1.1℃、0.5℃、0.5℃、0.6℃、0.6℃.The amount of enhancing soil moisture in 0～10,10～20,20～30 cm and 30～40 cm soil layer was 18.84%、10.67%、11.12% and 8.9%.Under cultivation with plastic mulching,it increased sucrase activity,phosphatase activity,number of soil microorganism,CO2 concentration,soil respiratory intensity,NO-3-N content and decreased loss of soil nitrogen.Simultaneity it decreased soil organic,N,avail N,avail P,catalase activity,urease activity and salinity content in soil surface layer.Thus plastic film mulching increased maize yield and biomass. |