【摘要】 <正> 随着我国农业生产的不断发展,复种指数和单位面积产量的不断提高,南方不少地区施用钾肥已成为夺取高产稳产的重要条件之一,有关土壤钾素状况和钾肥施用问题愈来愈受到人们的重视。江苏省地处我国南北的过渡带,其土壤是否缺钾,钾肥的需要程度如何,是生产实践上有待明确的一个问题。为此,自1973年以来,我们对江苏省土壤钾素的更多还原

【Abstract】 The potassium contents of various soils in Kiangsu differ greatly. Analysis of more than seven hundred representative soil samples selected from different parts of the Province showed that the contents of available K （1N NH₄OAc extractable） in soils ranged 4.8—32.0mg K₂O/100 g soil, slowly available K （soluble in boiling 1N HNO₃） 20.9—145.1 mg K₂O/100g soil, and the total K₂O 1.41—2.67% （for detailed informations refer to table 1 in the Chinese text）. It was found that the parent materials and their degree of weathering, and soil texture have coused such differences.The corn plants grown in greenhouse indicated that the amount of potassium taken up by the plants in different soils was closely correlated to the level of initial available soil K （r=0.94）. Extensive results from field experiments revealed that good responses of crop yield to K fertilizer was found on the soils with low level of available K. However, in certain cases, good correlation between the crop yield and the contents of slowly available soil K were found. In present investigation, the potassium suppluing power of soils in Kiangsu was classified into six levels in accordance with contents of available and slowly available K. In general, potash should be applied to the soils at low K-level, such as various whitish soils in southern Kiangsu and the pao-chiang soil （a bleached sandy brown soil） in northern Kiangsu and others. Potassium fertilizer was recommended for K-sensitive crops, such as cotton, sugar-beet, tobacco, peanut and soybean in the soils of K-supplying power below medium level. In the high productive soils of Tai Lake area where dressing of N, P fertilizers was usually higher, application of K fertilizer was also beneficial. However, in the saline soils of the coastal area and in the alluvial deposits of silt clay texture along the old Yellow River as well as in the rice soils developed from lacustrine deposits where potassium supply was usually high, K fertilizer was unnecessary.更多还原