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Soil management principles in climate-smart conservation <BR>agriculture to halt and reverse land degradation (Communication session)
EUROSOIL2020CONT-1741
EFFECT OF ADDING UNDECOMPOSED ORGANIC MATTER INTO SUBSOIL ON SUBSOIL BIOLOGICAL ACTIVITY, NUTRIENT AVAILABILITY, AND CROP YIELD – A SHORT-TERM INVESTIGATION
Mohammed M. Parvage* 1, 2, Holger Kirchmann1, Gizachew T. Getahun1, Gunnar Börjesson1
1Soil and Environment, Swedish University of Agricultural Sciences, 2Earth Sciences, Uppsala University, Uppsala, Sweden
Content: Subsoils are equally fertile as the topsoil, however, the root growth into the subsoil and uptake of water and nutrients from soil-depth is hindered due to compaction. Therefore, creating soil conditions that allow extensive root growth into the subsoil is crucial for yield increase without further increase of fertilizer input. In this project, we have tested the feasibility of crop residue addition in the subsoil by adding straw channels (8 cm thick and wide, 68 cm apart) and evaluated its impact on soil microbial communities, some chemical parameters (e.g., pH, water soluble P, total organic C, total N, C/N ratio), and crop yield. Results showed that straw addition in subsoil increased total microbial biomass by 17 folds, and organic carbon by 3 to 4 folds. Also, availability of water-soluble phosphorus and total nitrogen increased from 0.71 to 1.78 mg kg-1 and from 0.20% to 0.29%, respectively, in the straw amended subsoil than in the control subsoil. However, as we followed the changing pattern of the measured parameters over the growing season (spring, summer, & autumn), we noticed that the treatment effect was different for different parameters. In addition, the treatment effect was noticed up to 10 cm lateral distance and 5 cm above and below to the residue layer. Regarding crop yield, 5-10% higher yield was recorded from the straw amended plot than the traditionally managed soil (control soil). These results suggest that subsoil amelioration with crop residue can have a positive impact on soil biology, carbon build-up, nutrient availability & crop performance.
Disclosure of Interest: None Declared
Keywords: carbon sequestration, crop yield, microbial diversity, nutrient availability, organic matter, soil management, Subsoil