Study on efficiency of K-absorption and K-equilibrium of major grain crops in Hexi area

The result of 4 successive years of fixed position test shows that the natural K supplying rate of the soil in this area is 62.0%~78.9%.After applying 62.0 kg/hm 2 ~187 kg/hm\-2 chemical containing K element, K supplying rate can be raised by 18.5% ~32.9% in the soil with strip cross cropping, by 23.7%~31.2% and 17.0%~ 20.4% in the soil with wheat and corn respectively, and it presents a positive relation with the amount of the K applied. When applying 75 t/hm 2, K supplying rate can be raised by 45.5% in the soil with strip cross cropping, by 23.9% and 8.8% in the soil with wheat and corn respectively. 76.5%~82.7% of the K absorbed by crops is from the soil.\;