Effect of long-term fertilization on nutrient distribution in profiles of black loessial soil

Nutrient distributions of the profiles of black loessial soil were studied after N and/or P were applied for 15 years continuously The results showed that organic matter, total N, total P, NO3--N, Olsen P of fertilization treatments were increased in the 0～20cm soil layer and nutrient contents of 0～20cm and 20～40cm layers were higher than that of CK, which leads to lack of nutrient content Higher N rate applied to result the accumulation of NO3--N leaching Higher P applied to increase the Olsen P content in the 0～20 soil layer remarkably, but not to effect on Olsen P under the 20cm depth