Leaching and Redistribution of Nutrients in Surface Layer of Red Soils in Southeast China

摘要

The leaching and redistribution of nutrients in the surface layer of 4 types of red soils in Southeast China were studied with a lysimeter experiment under filed conditions.Results showed that the leaching concentrated in the rainy season(from April to June).Generally,the leaching of soil nutrients from the surface layer of red soils was in the order of Ca>Mg>K>NO3-N,In fertilization treatment,the total amount of soil nutrients leached out of the surface layer in a red soil derived from granite was the highest in all soils.The uptake by grass decreased the leaching of fertilizer ions in surface layer,particularly for No3-N,Soil total N and exchangeable K,Ca and Mg in the surface layer decreased with leaching and grass uptake during the 2 years without new fertilization of urea,Ca(H2PO4)2,KCl,CaCO3 and MgCO3,Ca moved from the application layer(0-5cm) of fertilizer and accumulated in the 10-30cm depth in the soils studied except that derved from quaternary red clay.The deficiency of soil exchangeable K will become a serious degradation process facing the Southeast China.