不同容重梯度下不同改良材料对土壤结构特性的影响
Effects of Different Improved Materials on Soil Structural Characteristics under Different Unit Weight Gradients

针对关中地区土壤过于紧实、犁底层增厚上移、土壤团聚体数量减少、结构稳定性变差等生态环境问题，采用野外实地监测、室内模拟实验相结合的方法，分析1.0、1.1、1.2、1.3、1.4、1.5六个不同容重水平下草木灰、有机肥、生物炭添加对土壤结构改良情况。结果表明：随容重逐渐增加，土壤紧实度、压实密度呈增加趋势，土壤孔隙度呈降低趋势，土壤含水量在土壤容重为1.1时变为下降趋势，到容重1.4时转为上升趋势，土壤容重为1.2和1.3时，作物株高较高；在容重不同梯度下，草木灰对作物株高影响最大，生物炭对土壤压实密度、含水量影响最大，有机肥对土壤孔隙度影响最大。在关中地区土壤紧实化治理中，若该区水分供应充足则添加草木灰的土壤环境对植物生长发育更有利，若该区水分为主要限制因子，则添加生物炭是土壤结构改良的最佳措施。
In view of the ecological and environmental problems, such as excessive soil compactness, thick-ening of the bottom layer of the plough and upward shift, reduction of the number of soil aggregates, and deterioration of structural stability in Guanzhong area, combined with field monitoring and indoor simulation experiments, the improvement of soil structure by the addition of plant ash, organic fertilizer and biochar at different bulk density levels of 1.0, 1.1, 1.2, 1.3, 1.4 and 1.5 was analyzed. With the gradual increase of bulk density, soil compactness and compaction density show an increasing trend, and soil porosity shows a decreasing trend. The soil water content becomes a downward trend when the soil bulk density is 1.1, and an upward trend when the soil bulk density is 1.4. When the soil bulk density is 1.2 and 1.3, the plant height of crops is higher. Under different gradients of unit weight, plant ash has the greatest impact on plant height of crops, biochar has the greatest impact on soil compaction density and water content, and organic fertilizer has the greatest impact on soil porosity. In the process of soil compaction in Guanzhong area, if the water supply is sufficient in this area, the soil environment with plant ash is more favorable for plant growth and development. If water is the main limiting factor, adding biochar is the best measure to improve soil structure.