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多点调查表明 ,河西灌漠土全钾、速效钾比 70年代末平均降低了 2 2 %和 4 1.2 % ,耕层全钾、缓效钾、速效钾平均含量分别为 1.4 2 %、10 34mg/kg和 14 2 mg/kg。带田作物及小麦、玉米、甜菜、马铃薯单作 ,当季施钾均无明显增产效应。当土壤速效钾为 70 mg/kg以下时 ,春小麦、玉米、施钾显效 ;缓效钾为 70 0 mg/kg以下、速效钾 12 0mg/kg以下时 ,带田作物施钾显效。
Multi-point survey showed that the total potassium and available potassium in irrigated desert soil in Hexi area decreased by 22% and 42.2% on average compared with the end of 1970s, and the average content of total potassium, slow-acting potassium and available potassium in topsoil were respectively 1.4 2% and 10 34mg / kg and 14 2 mg / kg. With field crops and wheat, corn, sugar beet, potato monoculture, the season of potassium were no significant increase yield effect. When soil available K was less than 70 mg / kg, spring wheat and corn were significantly effective when applied potassium. When slow-acting potassium was below 70 0 mg / kg and quick-acting potassium was below 120 mg / kg, the yield of potassium was significantly higher in field crops.