东北典型黑土区旱地耕层土壤肥力指标的纬度变化特征及其关系

[目的]明确东北典型黑土区土壤肥力指标的纬度特征及其关系,探究黑土地核心地带肥力调控的问题,为黑土地耕地质量调控和国家粮食稳产增产提供有力支撑.[方法]2018 年秋收后,在研究区按纬度梯度采样,测定土壤有机质、酸碱度、全磷、全钾、速效磷、速效钾、碱解氮、容重、大微团聚体质量比等肥力指标和土壤含水量、土壤温度等环境指标...

Spatial Variations and Relationships of Topsoil Fertility Indices of Drylands in the Typical Black Soil Region of Northeast China

【Objective】In order to clarify the latitude characteristics and relationships among soil fertility indices in the typical black soil region of northeast China, clarify the problems of fertility control in the heart of black land and provide strong support for the quality control of black land cultivated land and grain yield stable and increase.【Method】Soil samples were collected following by latitude gradient in the study area after the autumn harvest in 2018. The soil fertility indices, such as soil organic matter, pH, total phosphorus, total potassium, available phosphorus, available potassium, alkali-hydrolyzable nitrogen, bulk density, soil water content, soil temperature the ratio of macro- and micro-aggregates, soil water content and soil temperature, were measured to investigate these indices’ latitudinal variation characteristics and their relationships by means of principal component analysis, redundancy analysis and correlation analysis. 【Result】The soil fertility indices of typical black soil region in Northeast China showed obvious latitudinal variation characteristics. In addition to the weak variation of bulk density, other fertility indices showed medium variation. Soil organic matter was the core influencing index in this region, which was increasing with the increase of latitude, and had a significant positive correlation with the ratio of macro- and micro-aggregates, alkali-hydrolyzable nitrogen, available phosphorus, available potassium, total potassium, total phosphorus and pH. Nevertheless, it was negatively correlated with soil water content, soil temperature and bulk density. The soil fertility indices with latitude between 46.07 ° and 49.18 ° were greatly affected by the change of soil bulk density, while the indices with latitude between 42.99 ° and 45.59 ° were combined action with soil bulk density, organic matter content and pH.【Conclusion】In the latitude range of 46.07 ° to 49.18 °, the soil fertility indices could be regulated by improving soil bulk density, while in the latitude range of 42.99 ° to 45.59 °, the soil nutrient should be comprehensively regulated by soil testing and formulated fertilization. For the whole study area, the regulation of soil organic matte was still an important content of soil fertility.