重庆市山区小流域耕地土壤养分分布特征

Distribution Characteristics of Soil Nutrients in Cultivated Land in Small Watershed of Mountainous Area of Chongqing

为给山区土地资源的合理利用以及土壤肥力现状评价提供科学依据,采用小流域实地采样到实验室测定分析,对小流域耕地全氮、全磷、全钾、速效磷、速效钾、有机质和pH共7个养分指标进行统计分析,总结其土壤养分分布特征。结果表明:1)研究区土壤速效磷与速效钾相对缺乏,建议在农业生产中增施磷肥与钾肥;土壤大部分属于中强酸到强酸性土壤,种植应尽量选择喜酸、耐酸性作物。2)研究区土壤全钾、速效磷、速效钾含量表现为流域底部>流域中部>流域顶部,土壤养分含量随坡度变大而呈降低的大致趋势,因此在流域海拔高、坡度较大地区应注意防止和减轻水土流失。3)研究区土壤养分的变异系数均较高,且在不同耕地条件下,所有养分指标的变异系数均为旱地大于水田,在平时耕作中应注意加大翻耕力度,促使土壤养分均匀化。

This purpose of the article was to provide scientific basis for rational utilization of land resources and evaluation of soil fertility status in mountainous area.The contents of total nitrogen,total phosphorus,total potassium,available phosphorus,available potassium,organic matter and pH in cultivated land in small watershed were analyzed by field sampling and laboratory determination.Results:1)The available phosphorus and potassium were relatively deficient in the study area,so it was suggested to increase the application of phosphorus and potassium fertilizer in agricultural production;Most of the soils in the study area belong to medium to strong acidic soils,so the selection of crops should be beneficial and avoid harmful effects,and acid-loving and acid-tolerant crops should be selected as far as possible.2)The contents of total potassium,available phosphorus and available potassium in the soil of the study area were as follows:the bottom of the watershed>the middle of the watershed>the top of the watershed.The soil nutrient content shows a general trend of decreasing with the increase of the slope.Therefore,attention should be paid to preventing and reducing soil erosion in the high altitude and large slope areas of the basin.3)The coefficient of variation of soil nutrients in the study area was relatively high,and under different conditions of cultivated land,the coefficient of variation of all nutrient indicators of dry farm in the study area were higher than that in paddy field.In peacetime tillage,attention should be paid to increasing tillage intensity to promote the uniformity of soil nutrients.