Document Type : Research Paper
Authors
1 Soil Conservation and Watershed Management Department, Kermanshah Agricultural and Natural Resources Research and Education Center, Agricultural Research,Education and Extension Organization (AREEO), Keshavarz Boulevard, Kermanshah,
2 Kermanshah Center for Agricultural and Natural Resources Research and Education, Agricultural Research, Education and Extension Organization (AREEO), Kermanshah, Iran
3 Soil conservation and Watershed Management Institute, Agricultural Research, Education and Extension Organization (AREEO),Kermanshah, Iran
Abstract
Tillage is a common worldwide agricultural practice impacts soil quality, Thus, there is the worst practice contributing in soil quality depletion, carbon flux and crop yield decline. In order to study the effect of different tillage and crop residue retention on some soil characteristics, an experiment was carried out in a splite-splite plots. The experiments comprised four main treatments (tillage) and three sub-treatments (crop residue) with three replications. The main tillage treatments include conventional tillage using moldboard plow (T0); combined plow using delta basket roller model (T1); chisel packer plow (T2); and no tillage (T3). Sub-treatment included no crop residue, one third residue and two third residue. Research conducted for four-years (2017–18 to 2020–21). Soil sampling and analysis carried out annually for measurement of soil organic carbon (SOC) bulk density (BD) and soil aggregate size distribution (SASD) at depth 0-20 cm. Results showed that the mean BD value in the main treatments including T0, T1, T2 and T3 were about 1.62, 1.45, 1.40 and 1.37 gcm-3, respectively that was significantly (P<0.05) higher than conventional tillage (T0). The average SOC in T0, T1, T2 and T3 were about 1.20, 1.50, 1.40 and 1.70 %, respectively that was significantly higher in all conservation tillage, but higher in T3. Likewise SOC, the effects of conservation tillage on increasing ratio of coarser SASD > 1 mm) was significantly (p<0.05) higher that T0, and highest in no tillage. The effects of one third and two third crop residue retention on analysed soil variable was significantly higher compared to zero crop residue retention. Although all conservative tillage (T1, T2 and T3) contribute to obvious improvement of measured soil variables, the effects of no tillage (T3) coupled with highest crop residue was found highest value. Following this results, soil erodibilty was reduced through conservation tillage.
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