The spatial distribution and availability of soil potassium in loess plateau after 24 years of long-term fertilization were investigated in this study.The result showed that the quantity of potassium,except the nonspecifically absorbed K with the chemical fertilizer application,in the 0-20 cm soil layer was larger than that in 20-40 cm soil layer in all treatments and the quantity of potassium gradually decreased with depth below in the 60 cm soil layer.The quantities of K in 0-300 cm soil layer in the trea...