湖南省高产稻区稻田土壤的立地条件与肥力特性

通过野外调查采样和室内分析测定，研究了湖南省几个典型高产稻作区稻田土壤的立地条件和主要肥力特性。结果表明：供试稻作区均为海拔40-90m，地势低平、开阔的丘陵谷地和冲积平原；供试土壤由石灰岩风化物、河流沉积物和第四纪红色粘土发育而成。其总体养分状况良好。有机质23．29-64．32g/kg，平均为38．31g／kg；全氮1．44～4．31g／kg。平均为2．23g／kg；全磷0．36-1．00g／kg，平均为0．66g／kg；全钾16．13～25．68g／kg，平均为20．38g／kg；尤以有机质和氮紊含量高于其它耕地土壤；有效硅含量70．7-514．3mg／kg，大部分属中低水平，其中醴陵的浦口和白兔潭、浏阳永安的土壤有效硅含量均低于缺硅临界值（210mg／ks）。不同母质发育的土壤相比。石灰岩风化物发育的水稻土肥力水平较河流沉积物和第四纪红色粘土发育的水稻土高。土壤质地均为中壤土至轻粘土。砂粘适中。

Local conditions and fertility properties of typical paddy soils of several rice production areas in Hunan Province

By field investigation and sampling, and laboratory analysis, this paper attempted to study the local conditions and fertility properties of paddy soils of several typical rice production areas in Hunan Province. The results showed that the paddy soils are developed from the weathering product of limestone, the river alluvium and Quaternary Red Clay .The soil texture ranges from medium loamy to lightly clayey, and it is suitable to crop growth. The nutrient status of the soils was good on the whole, the contents of organic matter, nitrogen, phosphorus and potassium were all at the higher level, and especially the content of organic matter and nitrogen were much higher than that of the other cultivated soils; while content of available silica was at the lower level. Of them the paddy soil developed from the weathering product of limestone has much higher nutrient contents than the paddy soils developed from river alluvium and Quaternary Red Clay does.