Effect of Rice Husk and Bamboo Biochar on Soil Compaction in Paddy Fields under Varying Moisture Conditions

Soil compaction impacts the physical quality of paddy fields by hindering water infiltration, limiting aeration, and stunting root growth. The use of biochar has emerged as a promising approach to mitigate soil compaction and improve soil structure. This study aimed to investigate the effects of rice husk and petung bamboo biochar on soil compaction at different moisture levels. Laboratory assays employing standard compaction tests of soils were performed, and the resulting data were subjected to quadratic regression analysis. Both rice husk and petung bamboo biochars showed a quadratic relationship between soil moisture and compaction with R² values of 0.8512 and 0.9913, respectively. Also, rice husk biochar lowered soil compaction so that bulk density decreased from 1.393937 g.cm⁻³ at 27% (w/w) moisture to 1.2006 g.cm⁻³ at 41% (w/w) moisture. Meanwhile, soil with petung bamboo biochar reached a maximum bulk density of 1.3806 g.cm⁻³ at 36% (w/w) moisture and was stable at higher moistures. The effectiveness of biochars in reducing soil compaction is attributed to their physical properties such as porosity and density. From the results, it is suggested that the application of rice husk biochar effectively improves paddy field soil structure and supports sustainable agriculture practices