论文部分内容阅读
通过长期定位试验研究表明，在当前农业生产条件下，如果不施钾肥、不采用秸秆还田措施，华北地区小麦－玉米种植制的钾素年表观亏缺量在 １３４～２５８ｋｇ／ｈｍ ２；西北地区小麦－玉米轮作制的年表观亏缺量在２２０～２６１ｋｇ／ｈｍ ２ 之间。华北地区小麦－玉米种植制下，小麦秸秆还田能使作物吸收的近三分之一到一半的钾素归还土壤。施钾肥能使土壤－作物系统钾素的产出与投入更趋于平衡，乃至钾素在土壤中积累
According to the long-term experiment, the apparent annual deficit of potassium in wheat-corn planting system in north China ranged from 134 kg / hm 2 to 258 kg / hm 2 under the current agricultural conditions without applying straw and returning straw to soil. The annual apparent deficit of wheat-corn rotation in northwestern China ranged from 220 to 261 kg / hm 2. In North China, under wheat-corn cultivation, returning wheat straw to the soil allows nearly one-third to one-half of the potassium absorbed by the crop to be returned to the soil. Potash fertilizer can make the soil-crop system of potassium output and investment more balanced, and even the accumulation of potassium in the soil