宁夏不同地区温室土壤养分的变化特点

VARIABILITY OF N, PAND K CONTENTS OF GREENHOUSE SOILS IN DIFFERENT REGIONS OF NINGXIA

根据宁夏温室的分布状况,按照不同地区分别采集了温室和露地土壤,分析了土壤N、P、K养分含量的变化特点。结果表明,温室土壤的N、P、K养分含量明显高于露地,表现为相对累积,其顺序依次是NO3--N>速效P>速效K>碱解N>全P>全N。从不同地区来看,土壤N、K含量总体上是灌区高于山区,而土壤全P和速效P含量在两地区间差异不显著,但各养分含量的变异系数都是山区大于灌区。从不同县级地域来看,温室土壤养分含量在平罗县、兴庆区、西夏区、青铜峡市、中卫县、原州区、盐池县之间存在显著或不显著差异,其中盐池县的各养分含量最低,均显著低于其他各市县。

Based on distribution of greenhouses in Ningxia, soil samples were collected randomly from 0 ～ 30 cm topsoil layers of croplands and greenhouses located in different regions. Variability of the contents of N, P and K in the tested soils was analyzed. The results showed that the contents of N, P and K in the greenhouse soils were generally higher than that in the soils of open field. In terms of relative accumulation, the nutrients in greenhouse soils were in the order of nitrate N〉available P〉readily available K〉alkali-hydrolyzable N〉total P〉total N. The contents of these nutrients in the greenhouse soils showed a certain feature of geographic distribution. The contents of N and K （except for P） of the soils were generally higher in the irrigation region than in the mountain region, but the variation coefficients of all the nutrients were obviously the other way round. The differences in average contents of soil N, P and K between the six counties, Pingluo, Xixia, Xingqing, Qingtongxia, Zhongwei and Yuanzhou, were insignificant, but significant between the six and Yanchi County, which was the lowest in these soil nutrient contents.