甘肃省河东地区主要耕作土壤中钾素状况及钾肥肥效的研究

本文用盐栽经验、田间试验和室内分析的方法,对甘肃省河东地区主要耕作土攘中的钾素状况和钾肥肥效进行了试验研究,结果表明:1.河东地区四种耕作土壤中黄僵土,大黑土,黑垆土钾素供应潜力属高水平,而黄绵土属中上水平。2.钾素在不同土壤粒级中的分布以物理性粘粒含量最高。几类土壤均随<0.01 mm 的物理性粘粒含量增加,其供钾容量增大。3.黑垆土上施用钾不论单施或配合氮磷肥施用都有增产效果,而黄僵土上单施无效,配合氮、磷肥时有增产效果,这可能和该土壤氮,磷养分不足有关。4.通过黄绵土和黑垆土小麦幼苗吸钾模拟试验看出,黄绵土不施肥时土壤释放钾量很低,作物吸钾量也很少,施肥后能大幅度提高土壤有效钾含量和对作物的供钾量,所以在黄绵土上种植高产和喜钾作物时,应重视钾肥的施用。

Studies on the Potassium State and the Effects of Potassium Fertilizers in Main Cultivated Soils of Hedong Area in Gansu

The k state and the effects of k fertilizers in main cultivated soils of Hedong area in Gansu has been studied with the methods of pot and field experiments and indoor analysis.The results obtained were as follows:1.Among the four main cultivated soils in Hedong,the k potential supplied in yellow stiff soil,dark black soil and dark loessal soil was of high level and that in cultivated loessal soil was next to them.2.The highest content of k in separates of various soil was found in physical clay.The quantity of k prov-ided the soils all became larger with the increase of<0.01mm physical clay.3.In dark loessal soil the k fertilizers had an effect on crop yields whether they were applied alone or together with N and P fertilizers, while in yellow stiff soil,this effect appeared only when applied together with N and P fertilizers,this maybe attributed to the shortage of N and P in the soil.4.By the simulated test of k absorption by wheat seedlings in cultivated loessal soil and dark black soil,it might be seen that without k application,the cultivated loessal soil released less k and the crops also absorbed less,but k fertilization could greatly increase the available k content in the soil and its amount supplied to crops.Therefore.k fertilization is essential to cultivate high-yield and k-liking crops.