老挝北部山区主要土壤类型的养分状况

以老挝北部4种主要土壤类型为研究对象,分析不同土壤类型的养分含量和养分的垂直分布特点,为老挝农业生产过程中化肥的合理使用和老挝土地资源的可持续开发利用提供依据。结果表明:土壤pH值为5.46,呈微酸性;有机质含量为2.1%,处于中等水平;碱解氮、有效磷和速效钾的含量分别是109.4、3.26、93.4 mg/kg,含量比较低;交换性钙和镁的含量分别为1 735.9、328.9 mg/kg。不同土壤类型的养分含量随着土壤深度的增加呈现不同的变化规律和分布特征,在土地利用方式和肥料投入方面存在较大差异。因此,在农业生产中,要依据土壤养分状况合理调整施肥量。

The Nutrient Status of Main Soil Types in the Northern Highland of Laos

Four main soil types in the northern Laos were collected to analyze their nutrient content and vertical distribution so as to provide reference for rational use of chemical fertilizer and sustainable development and utilization of land resources in Laos.The results showed that the soil was slightly acid with the pH 5.46 and contained medium level of organic matter (2.1％) and a low level of alkaline hydrolysis nitrogen (109.4 mg/kg),available phosphorus (3.26 mg/kg) and available potassium (93.4 mg/kg).The exchangeable Ca and Mg contents were 1735.9 mg/kg and 328.9 mg/kg,respectively.The soil nutrient contents in different soil types were changed and distributed differently with the increase of soil depth,and there were significant differences between land use pattern and fertilizer inputs.Therefore,application rate of fertilizer should be adjusted according to the soil nutrient status in these four main soil types in agricultural production.