乌兰察布高原土壤腐殖质地理分布规律

本文研究了乌兰察布高原的地带性土壤府殖质的地理分布规律：（碱溶性腐殖质可提取的部分）以深厚黑色土为最高：８０－８７％；向北过渡至栗钙土、棕钙土明显降低在２０％左右，ＨＡ／ＦＡ亦是以深厚黑色土最高：土层中部达２以上；栗钙土１－１．５；至棕钙土０．６－１，并且表层最高，下部土层减少＜１；山地土壤ＨＡ／ＦＡ最高层在Ａ１层：１－１．３左右，向下锐减。光密度特性Ｅ４：Ｅ６：深厚黑色土最小＜４；草原土壤在４－５；山地土壤：＞５。土壤Ｃ／Ｎ也反映了土壤类型之间差异：深厚黑色土：表层低：６－７，下层高：１２－１３；草原土壤多在９－１０；山地土壤则较大１１－１３。通过对土壤以上各化学指标分析研究，明确了土壤类型的划分依据，对本区土壤分类中存在的几个问题进行初步探讨。

GEOGRAPHIC DISTRIBUTION OF HUMUS OF ZONAL SOILS ON WULANCHABU PLATEAU

The paper deals with geographical distribution pattern of humus of the zonal soils on the Wulanchabu Plateau,the results show that:①extractable alkali-soluble humus,80-87% for black soil in the south of the plateau,about 20% for chesthut soil and brown calcic soil in the north;②HA/FA,the highest is also black soil,more than 2 on middle layer,1-1.5 for chestnut soil,0.6-1 for brown calcic soil,mountainous soil,1-1.3 in A 1 layer and decrease sharply downwards;③E 4/E 6 of humic acid,<4 for black soil,4-5 for steppe soil,>5 for mountainous soil;④C/N,black soil,6-7 for surface,12-13 for deep layer,9-10 for steppe soil and 11-13 for mountainous soil. The above-mentioned indexes may provide reliable basis for classification of the soils on the plateau.