|Olk, Daniel - Dan|
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 2/15/2010
Publication Date: 8/1/2010
Citation: Guong, V.T., Nguyen, H.D., Merckx, R., Olk, D.C. 2010. Aerobic Decomposition and Organic Amendments Effects on Grain Yield of Triple-Cropped Rice in the Mekong Delta, Vietnam [abstract]. World Congress of Soil Science, August 1-6, 2010, Brisbane, Queensland, Australia, CD-ROM. Interpretive Summary:
Technical Abstract: Soil aeration during decomposition of incorporated crop residues and application of organic amendments might help improve soil quality and rice yield for sustainable intensive rice production. A field experiment was conducted on triple-cropped rice during three consecutive crops with five treatments in the Mekong Delta, Vietnam: (1) Conventional anaerobic decomposition of crop residues as a control; (2) Air-drying of soil for three weeks before planting to foster aerobic decomposition of crop residues; (3) Air-drying of soil for three weeks combined with application of 10 Mg ha-1 compost; (4) Air-drying of soil for four weeks before planting; and (5) Double-cropping of a rice-maize rotation. The intensity of soil reduction was greatest in continuous submergence of triple-cropped rice with anaerobic decomposition of rice crop residues (P<0.05). All treatments with aerobic decomposition during three weeks with and without organic amendments, and double rice crops rotated with maize led to increased levels of soil labile organic carbon, available phosphorus and nitrogen mineralization (P<0.05) compared to triple-cropped rice with anaerobic decomposition. Rice yield was also improved compared to triple-cropped rice (P<0.05). The mobile humic acid content in soils was not different among treatments, due to high replicate variability. Aerobic decomposition resulted in more available soil nitrogen and increased rice grain yield, and it might benefit long-term sustainability of continuous rice cropping in the Mekong Delta.