As a result, the method of using airslake-coal to produce potassium fertilizer including humic acid was varied with different crops.

因此，在利用风化含腐植酸钾肥时，应根据作物类型选择工艺路线。

The results showed: inncrease application of Ca, balance application of N and K and sprinkler irrigation could increase Ca content of lettuce leaves, reduce occurring of tipburn.

结果表明，增施钙肥，平衡氮、钾肥及采取喷灌方式均能增加菜叶片钙含量，减少干烧心发。