宁夏主要土壤的磷酸吸收系数及需磷量

Study on phosphate adsorption coefficient and its application in the major soils of Ningxia

用pH7.0的2%磷酸铵溶液测定了宁夏7种主要生产性土壤的磷酸吸收系数,结果表明,宁夏7种主要生产性土壤的磷酸吸收系数(PAC)介于8712～12998mg/kg之间,PAC值的大小与土壤物理性粘粒有极显著相关关系(r=0.8297)。主要生产性土壤黄绵土(黑垆土)、灌淤土、灰钙土依PAC的0.2%计算的小麦建议施磷量分别为53、54、59和43kg/hm2,与肥效函数法所确定的用量相近。

Determined the phosphate adsorption coefficient in the major productive soils of Ningxia with the solution of pH 7.0 and 2% ammonium phosphate. The results indicated that the PAC of the soils in Ningxia were situated between 8712 to 12998 mg/kg,its significant correlated with soil physical clay. The phosphoric fertilizer application amounts were 54?59 and 43 kg/hm2 respectively in soils of southern,northern and the middle of Ningxia. They were consistent with the application amount defined by the methods of fertilizer efficiencies function.