The Effects of Long-term Fertilization on Corn Yields and Soil Fertility

The black soil locate-fertilization research works in key grain middle area of Jilin province in recent 30 years were studied.The results showed that soil organic contents of plough layer reduce 0.11 g/kg per year by no-fertilizer treatment and the rate of mineralization was about 0.38% by single chemical fertilizer application.The increase rate was 0.3 g/kg per year by organic-inorganic fertilization.The transform trend of content of soil total nitro-gen was similar to soil organic matter.By organic fertilizer application can lessen soil unit weight and the range was between 0-0.06 g/cm3 while the trend showed expanding by no-fertilization and chemical fertilization.The soil total porosity and field capacity porosity of plough layer were increase and the vent porosity changed irregular.The maize yield of single organic fertilization was equal to chemical fertilization.Organic-inorganic compound fertilization was benefit to accumulation of soil organic matter,improve soil physical-chemical property,promote soil fertility,and the yield could stable increased.