Impact of drying-wetting cycles on the soil aggregate stability of Alfisols in southwestern China

• DOI: 10.2489/jswc.73.4.469
• Publication Date: 2018-07-05T18:25:35Z
• Authors: B. Hu; Y. Wang; B. Wang; Y. Wang; C. Liu; C. Wang
• Keywords: 0401 agriculture, forestry, and fisheries; 04 agricultural and veterinary sciences; 15. Life on land

Drying-wetting cycles are important environmental factors controlling potential changes in aggregate stability. However, the relationships between soil stability and drying-wetting under different breakdown mechanisms not clear. We conducted a simulation study to investigate effects of on three main (slaking, microcracking, mechanical breakdown) without organic matter inputs. Four initial size classes (i.e., 1 2, 2 3, 3 5, 5 7 mm) within clay-loam soil, which undergoes intense cycles, were selected subjected eight levels 0, 1, 7, 10, 15 cycles). Aggregate was measured with treatment methods involving fast wetting (FW), slow (SW), shaking after prewetting treatments (ST). Our showed higher resistance lower slaking. Compared mean weight diameter (MWD), normalized (NMWD) better indicator comparing susceptibility aggregates breaking up into smaller aggregates. The values NMWD for mm 0.1, 0.09, respectively, FW; 0.35, 0.34, 0.33, 0.32, SW; 0.46, 0.45, 0.44, 0.42, ST. This indicated that as increased, more prone down. varied greatly among mechanisms. For aggregates, decreased MWD by 61%, 67%, 70%, 53%, SW, 69%, 72%, 80%, 78%, FW, increased 5%, 7%, 8%, 36% first two while it 36%, 44%, 15% cycles. results influence provides an basis management practices yields insights improved understanding role