不同炭基改良剂提升紫色土蓄水保墒能力  

Effects of Different Carbonaceous Conditioners on Water Retention Capacity of Purple Soil

作　　者：柴冠群 赵亚南[1] 黄兴成[1] 张跃强[1,2] 石孝均[1,2] 

机构地区：[1]西南大学资源环境学院,重庆400716 [2]农业部耕地保育重点实验室,国家紫色土肥力与肥料效益监测站,重庆400716

出　　处：《水土保持学报》2017年第1期296-302,309,共8页Journal of Soil and Water Conservation

基　　金：国家科技支撑计划项目(2015BAD06B04)

摘　　要：通过连续2a田间试验,研究了5种改良剂(秸秆、有机肥、生物炭、炭基改良剂I和炭基改良剂Ⅱ)对紫色丘陵区坡耕地土壤水分库容、孔隙度和团聚体组成及稳定性的影响,分析了土壤水分特征参数与孔隙度和团聚体组成的关系,以期为紫色土区水土保持和土壤改良提供科学依据。结果表明,与不施改良剂(对照)相比,5种炭基改良剂都能提高土壤对降水的截存和保贮能力,显著提高了土壤饱和含水量、田间持水量、水分总库容、有效水库容及重力水库容,降低了土壤凋萎点含水量和无效水库容;不同改良剂提升作用大小为改良剂Ⅱ>改良剂I>生物炭>有机肥>秸秆>对照。施用改良剂I、改良剂Ⅱ、生物炭和有机肥显著提高了土壤孔隙度,降低了土壤容重,秸秆的效果不显著。施用炭基改良剂降低了<0.25mm的微团聚体含量,促进了小团聚体向大团聚体的转化,其中对粒径>5mm的机械稳定性大团聚体提升幅度最大,比对照提高14.5%~60.7%;5种炭基改良剂都显著提高了团聚体的平均重量直径及稳定性指数,以炭基改良剂I、炭基改良剂Ⅱ和生物炭的作用效果最大。土壤总库容、重力水库容和有效水库容与总孔隙度和毛管孔隙度以及土壤大团聚体含量呈正相关,而与土壤非毛管孔隙度和小团聚体呈负相关,土壤蓄水保水能力与土壤团聚体组成和孔隙度密切相关。因此,施用炭基改良剂通过促进土壤团聚作用,提高大团聚体含量和土壤孔隙度,进而增大土壤持水量和土壤有效水库容,是改善紫色土结构和提高紫色土坡耕地保水蓄水能力的有效措施。To investigate the effect of soil ameliorants on the composition and stability of soil aggregate and moisture storage capacity of slope cropland in purple hilly area, two-year filed experiment was conducted by employing five kinds of soil ameliorants including straw, organic fertilizer, biochar, carbonaceous ameliorant I and Ⅱ. The results showed that all these five carbonaceous ameliorants were also observed to have the ability on enhancing the sequestration and storage of soil for precipitation, which could further markedly increase the saturated soil moisture content and maximum effective water and flood detention storage and decrease the water content of wilting point. The effect of these five soil ameliorants on the maximum effective capacity followed the trend： Carbonaceous ameliorant Ⅱ〉carbonaceous ameliorant I〉biochar〉manure〉straw〉CK. The soil bulk density and soil porosity also received valid improvement after applying these ameliorants （besides straw）, which significantly decreased and increased, respectively. In addition, the mechanical stability and the water stable aggregate content of soil with particle size 〉0.25mm significantly increased after soil ameliorants applied, while the micro-aggregate （〈0.25mm） content decreased, suggested that the soil ameliorant could promote the conversion of small aggregate to large aggregate with the best promotion observed for 〉5mm particle （increased 14.5 to 60.7% compared with the contrast）. Employing these soil ameliorants had obvious effect （followed the trend： carbonaceous ameliorant I≈carbonaceous ameliorant Ⅱ〉biochar〉organic fertilizer〉straw〉control） on increasing the average weight diameter and stability index of aggregate. Correlative analysis showed that there was a positive correlation between total storage capacity, active storage capacity, flood detention storage capacity and total soil porosity, capillary porosity, content of large aggregate, and there was negative correlation with non-capillary poro

关 键 词：紫色土 坡耕地 改良剂 土壤水分库容 孔隙度 团聚体特征 

分 类 号：S152.4[农业科学—土壤学]