宁夏灌区不同种植年限温室土壤养分的变化特点

Variability of N, P and K Contents of the Greenhouse Soil in Different Planting Years in Irrigation Regions of Ningxia

根据宁夏灌区温室的分布状况,按照不同年限分别采集了不同层次的温室土壤,分析了土壤氮、磷、钾养分含量的变化特点.结果表明,温室土壤氮、磷、钾养分含量随种植年限(1～9 a)的延长总体上均呈增加趋势,但养分种类、土壤深度随种植年限的不同而增长幅度不同.方差分析表明,温室土壤氮、磷、钾养分含量在不同种植年限间总体上存在显著差异.从温室土壤氮、磷、钾养分含量与种植年限的二次拟合曲线及其求解结果来看,不同土层深度(0～15 cm,15～30 cm,30～60 cm)的土壤全氮、碱解氮、硝态氮、全磷、速效磷、速效钾养分含量达最高时的种植年限不同,多数集中在7～9 a之间.

Based on distributing locations of the greenhouse in irrigation regions of Ningxia,the soil samples in different layers (0～15cm,15～30cm,30～60cm) were collected by means of random sampling for both the different greenhouses and various planting years,respectively.The variational properties of the nutrient contents of nitrogen,phosphorus and potassium in the tested soils were analyzed.The results showed that total N, alkali-hydrolyzable N, nitrate N , total P, available P and readily available K contents increased with planting ages from one to nine years, but the increased rates were different in several layers(0～15cm,15～30cm,30～60cm). There were the highest level of total N, alkali-hydrolyzable N, nitrate N, total P, available P and readily available K contents from seven to nine years in the greenhouse soils and there were significant difference at 5% level in different planting years.