神农架山地土壤的基本肥力特征

为了解神农架地区土壤的基本肥力特征，在神农架进行为期20多天的野外土壤调查，采集156个土壤样品，并分析测定土壤砾石含量、pH值、有机质、碱解氮、速效磷和速效钾的含量．结果表明，神农架土壤砾石含量在0～87％之间，砾石含量大于10％的土壤占65．4％．土壤pH在3．8～8．0之间，酸性和强酸性土壤占73．1％，没有强碱性土壤．土壤有机质含量分别在1．9-144．0gkg。之间，有机质丰富的占50％．碱解氮、速效磷和速效钾含量范围分别为26～766、1．8～115．3和16-399mgkg-1，碱解氮丰富的土壤占67．3％，速效磷丰富的土壤不足20％，而缺乏的却占63％，速效钾丰富和缺乏各占30％左右．相关分析表明，土壤有机质、碱解氮、速效磷和速效钾相互之间均呈极显著的线性相关，土壤有机质与碱解氮的相关性最高，与速效磷的相关性最低．总之，神农架土壤具有砾质性，以酸性土壤为主，有机质和碱解氮处于丰富水平，速效磷处于缺乏水平，速效钾处于中等水平．

The characteristics of soil basal fertility in mountainous region of Shennongjia

In order to understand the basal characteristics of soil basal fertility in mountainous region of Shennongjia, we collected 156 soil samples during more than 20 days of field investigation in Shennongjia region. Thereafter, soil gravel content, pH, organic matter, alkali-hydrolyzable N, available P, available K was determined. The results showed that the value of above indexes had wide variation scope and various features. The gravel contents ranged from 0 to 870/6o in soil in Shennongjia region and the soil with more than 10% of gravel content counted up 65.4% of the total soil samples. Soil value of pH was within the scope of 3. 8 - 8. 0, but 73. 1% of soil in Shennongjia region was acid or highly acid soil and there was no strongly alkaline soil in this area. The soil organic matter ranged from 1. 9 to 144. 0 g kg-1 and the soil rich in organic matter contributed 50% of the total. The variation scope of alkali-hydrolyzable N, available P and available K was respectively within 26 -766, 1.8 - 115.3 and 16 - 399 mg kg 1 , and the soil rich in alakali-hydrolyzabe N was made up 67. 3% of total soil samples, but the soil rich in available P was no more than 20% of the total, while 63~ of soil was lack of available P. Soil rich in and lack of available K counted up about 300/60 of the total respectively. The correlation analysis indicated that there was significantly linear relationship between each other among the contents of soil organic matter, alkali-hydrolyzable N, available P and available K, but among the relationship coefficients of organic matter to alkali-hydrolyzable N, available P and available K, it was highest to alkali-hydrolyzable N and lowest to available P. In conclusion, the soil in Shennongjia mountain area was rich in gravels, organic matter and alkali-hydrolyzable N, lacking of availahle P and had a medium level of available K, tanking on acidity mostly.