云南蒋家沟泥石流滩地土壤肥力特性

蒋家沟泥石流滩地地势平坦，水源充足，热量丰富，是较好的土地资源。为促进滩地的开发利用，对滩地土壤肥力作了初步研究，结果表明：滩地剖面结构和土壤物理结构较差，沙石化现象严重；土壤微团聚体数量较少，粒级间比例不合理，水稻田表层土微团聚体主要集中在0．02～0．002mm，旱作表层土微团聚体主要集中在0．25～0．05mm；土壤养分除全钾极丰富外，其它养分都处于缺乏或极缺状态；在开发过程中，全氮增加显著，其它养分含量变化不大，有效钾呈下降趋势。

Soil Fertility Properties of Debris Flow Waste-shoal Land in Jiangjia Gully of Yunnan Province

Debris flow waste-shoal land, with proper sunshine and abundant water resource and gentle slope, is a kind of land resource in Jiangjia gully. In order to exploit the debris flow waste-shoal land, the soil fertility properties are studied. The results indicate that, (1) The soil of debris flow waste-shoal land is stoned and sanded seriously. The power of absorbing and supplying moisture and nutrients is low, which is concerned on soil layers and soil particle composition. (2) The microaggregate of the debris flow waste-shoal land is less, mainly distributed in 0.02 to 0.002 mm in the rice-field topsoil and in 0.25 to 0.05 mm in the dry land. (3) The soil nutrient is poor. Organic matter, total N, total P, available N, available P and available K are lack seriously. Wherever total K is abundant, and the applications of organic and inorganic fertilizer, and siltigation are advantageous to improve the soil synthetic fertility.