生物炭不同添加量对旱作覆膜农田土壤团聚体特性及有机碳含量的影响

【目的】研究西北旱作区长期地膜覆盖农田添加不同量生物炭对土壤团聚体稳定性和有机碳含量的影响，为旱作覆膜农田地力提升、作物的可持续生产提供科学依据。【方法】在连续多年双垄沟覆膜农田基础上，采用裂区设计，主区为全膜双垄沟覆盖种植和传统平作不覆膜种植2个处理，副区为生物炭添加水平，分别为不添加(N)、低量添加(L):3 t·hm^-2、中量添加(M):6 t·hm^-2和高量添加(H):9 t·hm^-2。测定生物炭不同添加量对覆膜农田不同粒级土壤团聚体含量、团聚体稳定性、团聚体有机碳含量及玉米产量的影响。【结果】生物炭连续添加两年后，各覆膜处理能显著提高0—60 cm土层土壤大粒级(>0.25 mm)团聚体的机械稳定性(6.1%—8.7%)及水稳性团聚体的百分含量(15.9%—83.6%)，玉米产量可显著(P<0.05)提高35.0%—41.8%。在覆膜条件下，添加生物炭能显著提高土壤大粒级团聚体百分含量及其稳定性，干筛>0.25 mm粒级团聚体含量(MR_0.25)和湿筛>0.25 m...

Effects of Different Biochar Application Rates on Soil Aggregate Characteristics and Organic Carbon Contents for Film-Mulching Field in Semiarid Areas

【Objective】The aim of this study was to investigate the effects of long-term plastic film mulching farmland combined with different biochar input rates on soil aggregate stability and organic carbon in northwest China, in order to provide a scientific basis for improving the soil fertility and maintaining the sustainability of crop production for film-mulching field in semiarid regions. 【Method】Based on continuous years of double ridge furrow film mulching (D), the full film double ridge furrow mulching planting and traditional flat without film mulching planting were set as the main treatment, and four biochar input rates (no returning (N), 3 t·hm^-2 (L), 6 t·hm^-2 (M), and 9 t·hm^-2 (H) ) were set as the secondary treatment respectively to investigate the effects of different biochar input rates on soil aggregate distribution, aggregate stability, aggregate organic carbon and maize yield.【Result】The film mulching could significantly (P<0.05) increase the soil mechanical stable (6.1%-8.7%) and water-stable macro-aggregate contents (15.9%-83.6%) and maize yield (35.0%-41.8%). Under the film mulching planting, biochar inputs treatments could significantly (P<0.05) increase mechanical macro-aggregate and water macro-aggregate by 6.8% and 29.6% on average, respectively, and the effects gradually increased with the increase of biochar inputs rate. In addition, biochar inputs could also increase the soil organic carbon and aggregate organic carbon content in film mulching farmland, and the effects under DH (9 t·hm^-2) were better than other treatments, with an average increased by 13.9% and 25.9%, respectively. Maize yield was significantly correlated with biochar addition rates ( λ=0.42, P<0.001 ), and DH had the highest yield with 12.8 t·hm^-2. 【Conclusion】Biochar input could significantly improve soil aggregrate characteristics and organic carbon content in plastic film mulching farmland, thus increase the maize yield and promote soil carbon sequestration, especially with 9 t·hm^-2.