施用有机肥对土壤团聚体稳定性的影响

施用有机肥是循环农业的典型措施,能够净化环境、保证食品安全、加强土壤的可持续利用。本文以中国农业大学曲周试验站长期设施蔬菜地为研究对象,试验已进行6年,共设单施有机肥、有机无机配施与无机肥3种施肥处理。结果表明:施用有机肥处理的土壤有机C含量显著高于有机无机配施和无机肥处理107.02%、171.71%;干筛分析表明有机肥处理下的土壤非水稳性团聚体的平均重量直径(WMD)和几何平均直径(GMD)值均显著高于有机无机配施与无机肥65.68%、4.18%和16.80%、8.26%;湿筛结果也表明有机肥处理下的土壤水稳性团聚体WMD、GMD值显著高于有机无机配施与无机肥41.12%、34.78%和77.78%、63.16%;0~20 cm耕层有机肥处理增加了土壤分散系数,而20~40 cm耕层有机肥处理显著降低了土壤分散系数。在蔬菜有机栽培中单施有机肥可增加土壤有机C、非水稳性团聚体、水稳性团聚体及耕层下微团聚体含量,是改良土壤结构的有效措施。

Effects of organic manure application on stability of soil aggregates

Organic manure application is a typical measure of circular agriculture, which can ensure food healthy and improve soil sustainable utilization. The vegetable greenhouse at Quzhou research station was selected to study the effects of organic manure on the stability of soil aggregates, three different treatments were designed, i.e., organic manure application, chemical fertilizer mixed with organic manure, chemical fertilizer application. The results after 6a showed that soil organic carbon content of organic manure application was 107.02% and 171.71% respectively higher than chemical fertilizer mixed with organic manure and chemical fertilizer; the mean weight diameter r (MWD) and geometric mean diameter (GMD) of water-unstable aggregates of organic manure application were 65.68%, 4.18% and 16.80%, 8.26% respectively higher than chemical fertilizer mixed with organic manure and chemical fertilizer in dry sieving; the MWD and GMD of water-stable aggregates of organic manure application were 41.12%, 34.78% and 77.78%, 63.16% respectively higher than chemical fertilizer mixed with organic manure and chemical fertilizer in wet sieving; organic manure application increased soil disperse coefficient at 0-20cm soil layer, but reduced soil disperse coefficient at 20-40cm soil layer. Organic manure application can increase soil organic carbon content, water-instable aggregate and water-stable aggregate, and the microaggregate content below the tillage layer, thus it is the effective measure to improve soil structure.