集约化种植下潮土养分肥力与团聚体特征相互关系研究

通过测定封丘潮土7个肥力指标有机质、全氮、碱解氮、全磷、有效磷、全钾和速效钾,并利用主成分分析方法划分为3种肥力等级(一等、二等和三等肥力),研究了集约化种植条件下潮土养分肥力与团聚体特征的相互关系。结果表明:3种肥力等级下,大团聚体的质量比例最高,微团聚体居中,而粉黏粒最低。在0~5、5~10和10~20 cm土层,一等肥力下大团聚体的质量比例分别较三等肥力提高了25.5%、20.0%和18.5%,而微团聚体的质量比例分别降低了54.3%、43.5%和33.6%;一等肥力和二等肥力土壤团聚体的质量比例之间差异不显著。水稳性大团聚体的数量及其稳定性分别与由7个土壤肥力指标组成的养分肥力系统综合主成分得分F值呈线性正相关关系。7个肥力指标中,有机质、全氮和碱解氮与潮土大团聚体的质量比例及其稳定性显著正相关,并且这种相关性随着土壤深度增加而逐渐减弱。

Research on Relationship Between Soil Nutrient Fertility and Aggregation of Fluvo-aquic Soil Under Intensive Cultivation

In this study, the objective is to investigate the relationship between soil fertility and aggregate characteristics under intensive cultivation. Seven kinds of fertility indexes composed of soil organic matter, total and alkali-hydrolyzable nitrogen, total and available phosphorus, and total and available potassium were determined for Fluvo-aquic soil in Fengqiu county, which formed fertility system divided into three kinds of soil fertility grades (first-, second- and third-class) by principal component analysis. The results showed that the mass proportion of aggregates was ranked in the order of macro-aggregate > micro-aggregate > the free silt + clay fraction under any kind of fertility level. Compared to the third-class fertility, the mass proportions of macro-aggregates following the first-class fertility in the 0-5cm, 5-10cm and 10-20cm layers were increased by 25.5%, 20.0% and 18.5%, respectively, while the micro-aggregates were decreased by 54.3%, 43.5% and 33.6%, respectively. No significant differences were showed in aggregate distributions between the first- and second-class fertility. Soil macro-aggregates and the stability of the aggregates were significantly, positively and linearly correlated with the F-measure from principal component scores, as well as significantly positively correlated with soil organic matter, total and alkali-hydrolyzable nitrogen. The correlations between fertility indexes and aggregation would be weakened with increasing soil depth.