The results showed that the potassium surplus was 57.72 (kg/hm~2) in NK treatment and deficit of 192.97 (kg/hm~2) in NPK treatment during the 1978 to 2000 years.

• 结果表明,1978年到2000年,土壤钾素收支平衡的状况为:氮钾肥处理钾盈余57 72kg/hm2,氮磷钾肥处理钾亏缺192 90kg/hm2。