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通常认为,禾本科的粮食作物对钾素的需要不如经济作物,象太湖地区这样的中、高产土壤,施用钾肥的增产效果并不十分显著。但是,近年来随着有机肥料投入的变化,氮素化肥施用量的增加,磷肥的推广施用以及粮食作物产量的提高,土壤的钾素出现了投入少、提取多的状况,粮食作物施钾的增产效果愈来愈明显,并在生产中迅速推广,近五年全市稻、麦施钾面积达619万亩。我市最近的土壤普查资料表明,耕层土壤的速效钾含量减少很快,目前平均为83ppm,大大低于高产所需要的100ppm以上的养分指标。吴江县1984、1985两年对33个土
It is generally believed that the gramineous food crops do not need potassium more than cash crops, and medium and high yielding soils such as the Taihu Lake region are not very significant for increasing the yield of potash. However, in recent years, with the input of organic fertilizers, the increase of nitrogen fertilizer application, the promotion and application of phosphate fertilizers and the increase of grain crops, there is less input and more extraction of potassium in soils, Increasing yield more and more obvious, and the rapid promotion of production in the past five years, the city’s rice, wheat potassium area of 619 acres. Recent census data from our city indicate that the available potassium content in the topsoil has decreased rapidly, with an average of 83 ppm currently, well below the nutrient threshold of 100 ppm required for high yield. Wujiang County 1984,1985 two years to 33 soil