EFFECTS OF PHOSPHORUS APPLICATION METHODS ON NUTRITION UPTAKE AND SOIL PROPERTIES OVER 12-YEAR FIELD MICRO-PLOT TRIALS:I. PHOSPHORUS UPTAKE AND SOIL TEST PHOSPHORUS

摘要

A 12-year field micro-plot trial with meadow brown soil (silty loam Hapli-Udic Cambisols in Chinese soil taxonomy) and corn (Zea mays) was conducted in Shenyang, Northeast China to examine the effects of phosphorus application at a rate of 25 and 75 kg P hm~(-2) annually, or of 150 and 450 kg P hm~(-2) once every six years, on P uptake and soil test P. No significant differences were observed in the grain yield and stalk biomass of test crop between no P application and P applications, no matter what the P application rate or frequency was. However, P uptake and soil test P increased with increasing P application rate. When the P was applied once every six years, both P uptake and the soil test P were higher in the first years, but decreased gradually over time. In sum, P application rate and frequency less affected the 12-year average crop yield and soil test P, suggesting that for the corn production on Northeast China meadow brown soil, chemical P fertilizer could be applied at a proper rate once for several years, though the environmental risk of soil P loss needed to be carefully considered under the application of higher P amount.