成都平原不同耕作模式的农田效应研究--Ⅱ.土壤综合质量评价

Effects of Tillage Systems on Fields in Chengdu Plain——Ⅱ.The Evaluation of Soil Quality

【目的】研究成都平原不同耕作模式对土壤质量性状的影响,探索建立适合当地生产条件的土壤质量评价体系,筛选出适宜该地的耕作模式,为提高当地土壤生产力水平、改善土壤质量提供借鉴。【方法】通过长期定位试验获取不同耕作模式对土壤性状及作物生产指标的影响效应,采用主成分分析的方法筛选评价指标,运用因子分析法对土壤质量进行综合评价。【结果】筛选出的评价土壤综合质量的指标在不同土壤层次存在明显差别:0—10 cm土层的主要影响因子为毛管孔隙度、土壤比重、土壤饱和渗水速率、土壤紧实度、土壤有机质;10—20 cm土层的主要影响因子为总孔隙度、非毛管孔隙度、饱和渗水速率、土壤吸湿水、土壤紧实度;0—20 cm土层的主要影响因子为非毛管孔隙度、土壤比重、土壤饱和渗水速率、土壤紧实度。其中,不同土层的共同影响因子——土壤饱和渗水速率和土壤紧实度是目前当地土壤质量的限制因子。土壤质量综合评价结果表明0—10 cm土层以麦稻双免耕作模式最好,10—20 cm土层麦免+稻旋最好,0—20 cm土层麦免+稻旋最好。【结论】在本研究的试验条件和当地实际情况下,对成都平原土壤质量具有良好效益的耕作模式为麦免+稻旋模式。

【Objective】This paper evaluated the effects of the tillage systems on soil quality in Chengdu Plain.The soil quality evaluation system which is suitable to the local production conditions was explored and established.In order to provide reference for enhancing the local soil productivity levels and improving soil quality,the suitable tillage systems were selected.【Method】The soil properties of different tillage systems and their effects on the crop yield index were acquired by using long-term field tests.Using principal component analysis,the evaluation index and the soil quality were evaluated and screened by the factor analysis method.【Result】A significant difference was found in comprehensive evaluation of soil quality indicators in different soil layers.The main factors in 0-10 cm are capillary porosity,soil specific gravity,seepage rate of soil saturation,soil compaction and soil organic matter.The main factors in 10-20 cm are total porosity,non-capillary porosity,soil hydroscopic water and soil compaction.The main factors in 0-20 cm are non-capillary porosity,soil specific gravity,seepage rate of soil saturation and soil compaction.The same factors in different soil layers are seepage rate of soil saturation and soil compaction,which showed that they are the local limiting factors of soil quality currently.The results of soil quality assessment showed that wheat and rice no-tillage is the best tillage system in 0-10cm,wheat no-tillage and rice conventional tillage are the best in 10-20 cm and wheat no-tillage and rice conventional tillage are the best in 0-20 cm.【Conclusion】 Under this experimental conditions and local conditions,the good efficiency tillage system for the soil quality in the Chengdu Plain is wheat no-tillage and rice conventional tillage system.