【摘要】 带状间作4年定位试验表明,增施化学K肥平均增产17.0％～20.3％,土粪基础上K肥增产时限推迟2年。连续18年小麦、玉米定位轮作试验表明,土壤K素能保证2个轮作期(每轮3年)作物K素需求,第3～6轮作期施K平均增产10.3％～30.7%,增效与试验历程呈正相关,增施土粪土壤K素平均每年亏缺135.0～335.5kg/hm~2;增施化学K肥平均每年亏缺97.4～335.7kg/hm~2;等量土粪和化学K肥配合施用年均亏缺76.5～268.0kg/hm~2。无K投入时,连续种植作物土壤速效钾年均减少2.6～17mg/kg,施土粪带回速效钾年均下降7.5mg/kg,轮作田略有提高。在土粪基础上增施化学K肥能保持和提高土壤速效钾,土壤缓效钾下降速率是速效钾的6.5～8.2倍。更多还原

【Abstract】 4-year experiments on strip fields showed that the crop’s yield was improved by 17.0% --20.3% after adding potassium fertilizer, and the effective time of potassium was delayed when the manure was applied. The results of 18-year rotating experiments show that the potassium applied in soils can satisfy the crop need of 2 rotation periods (3 years per rotation) and the increased yield up to 10. 3% -30. 7% appears from the third to six rotations. There is a positive correlation between the potassium effect and experimental process. Each year, the potassium in soils decreases by 135. 0-335.5kg/hm2 when the manure is applied, decreases by 97. 4- 335. 7kg/hm2 when the chemical potassium is added, and reduces by 76. 5 -268. 0kg/hm2 when both are applied mixedly. The average available potassium in soils declines 2.6 -17mg/kg per year when continuous plantation is done without potassium and decreases by 7. 5mg/kg in strip-field but merely increased in rotated field. The mixed application of chemical potassium and manure can improve the available effect of potassium in soils. The decreasing rate of slow effective K is 6.5-8. 2 times of fast effective potassium.更多还原