河北省曲周县盐渍土区土壤养分含量的动态变化

对华北盐渍土区河北省曲周县 79个土壤样点 1 980年和 1 999年土壤养分含量进行了分析 ,结果表明 :1 999年与 1 980年相比 ,土壤有机质含量增加了 41 % ,土壤全氮和速效磷含量分别增加了 1 0 2 %和 351 % ,而土壤速效钾含量则下降了 38% ;土壤有机质含量增加的原因是秸秆还田量增加 ,土壤中全氮、速效磷含量增加的直接原因是土壤中氮肥、磷肥投入量增加 ,而土壤速效钾下降的原因则是钾肥的施入量不足。对不同质地土壤养分含量变化分析表明 ,质地可控制养分的空间分配 ,但人为干预促进了土壤养分含量向均一化方向发展。对不同质地土壤有机质含量与表层含盐量进行相关分析表明 ,表层为轻壤时 ,土壤有机质含量与表层含盐量具有明显的负相关性。

Changes in soil fertilities in saline soil region of Quzhou County,Hebei Province

Fertilities of the soil samples gathered from 79 soil sampling points in the saline soil region in the North China plain in 1999 were compared with those collected in 1980 of the same points.The results showed that the amount of organic matter,total N and Olsen-P in 1999 increased by 41%,102% and 351% compared with that in 1980,respectively.However,NH 4Ac-K decreased by 38%.The reasons of the changes were mostly related to increase in input of N and P fertilizer and inadequacy in input of K fertilizer.Nutrient content was also highly related to soil texture. But,as a result of human activities,the nutrient contents tended to be uniform.The correlative analysis between organic matter content and salinity of the surface layer showed significant negative correlation in soils with coarse texture;but not as significant in other cases.