Effects of Film Mulching and Chemical Fertilizer Application on Soil Organic Carbon Content and Corn and Soybean Yield
The field experiment in Anshun,Guizhou,examined the effects of film mulching and fertilization on soil organic carbon and corn and soybean yield.Four treatments were set up:non-film mulching without fertilization(non F+CK),non-film mulching with fertilization(non F+NP),film mulching without fertilization(F+CK),and film mulching with fertilization(F+NP).The results showed that mulching or fertilization did not significantly affect soil organic carbon(SOC).The soil microbial biomass carbon(MBC)content decreased by 9.1%and 10.2%after plastic film mulching under conditions of fertilization and no fertilization,respectively.However,fertilization led to a significant increase in soil MBC,ranging from 8.2%to 32.5%.The increase in TN due to fertilization varied from 2.9%to 76.5%,while there was a decrease of 11.4%(P<0.05)and 4.4%in TN under fertilization and no fertilization conditions,respectively.Compared with non-F+NP,F+NP treatment increased the yield of corn and soybean by 10.4%and 28.6%,respectively.The soil SOC had a positive correlation with both soil MBC and TN,and MBC and TN were also positively correlated with each other,but they were negatively correlated with C/N.The yields of corn and soybeans had a strong positive correlation with MBC.To sum up,plastic film mulching does not promote the increase of SOC and MBC content,whereas fertilization has the opposite effect.However,when combined,plastic film mulching and fertilization can lead to higher corn and soybean yields.