黎塘岩溶区铁锰结核背景下的土壤研究

对黎塘岩溶区铁锰结核背景下的土壤进行了分析。结果表明：研究区土壤以硅质土为主，土壤发育呈幼年性。土壤多呈中性，对土壤肥力的发挥及旱地作物的生长较为有利；有机质含量A层多为中等（Ⅲ级）或丰富（Ⅳ级），B层为缺乏（Ⅱ级）；全N含量A层多为中等（Ⅲ级），B层多为缺乏（Ⅱ级），有效N含量A层多为丰富（Ⅳ级）或甚丰富（V级），B层多为中等（Ⅲ级）或缺乏（Ⅱ级），A、B层养分含量的差异说明农耕区土壤受表层耕作、施肥影响较为显著。土壤有效P整体表现为缺乏或甚缺乏，可能已成为旱地作物生长的主要限制因子，阳离子交换量多表现为保肥力中等。

Study on Soil of Fe-Mn Nodules Background in Litang Karst

Soil of Fe-Mn nodules background in Litang karst was analyzed.The results showed that: the soil was mainly siliceous and juvenile;soil was mainly neutral and was beneficial for dryland crops;organic matter content in A layer was mostly middle(Ⅲ grade) or rich(Ⅳ grade),while that in B layer was lack(Ⅱ grade);the total N content in A layer was mostly middle(Ⅲ grade),while that in B layer was lack(Ⅱ grade);the effective N content in A layer was mostly rich(Ⅳ grade) or even rich(Ⅴ grade),while that in B layer was mostly middle(Ⅲ grade) or lack(Ⅱ grade).The nutrient difference between A layer and B layer indicated that surface farming and fertilization played important role.Effective P in the soil was overall lack and may have become the major limiting factor for growth.CEC was mostly middle for fertility capacity.