Soil physical and biological responses to rice establishment practices in rice-blackgram system

The field study, undertaken to assess the impact of different sowing dates and establishment methods in rice, along with weed management practices in blackgram, on the physical and biological properties of soil under rice blackgram system, was conducted using a split-split-plot design with four sowing dates as main plot treatments and rice establishment methods as sub plot treatments in kharif, and different weed management in conventionally sown blackgram as sub-sub plot treatments during rabi. The results revealed that early sowing and direct-seeded rice significantly improved soil physical properties such as bulk density, porosity and water stable aggregates due to better root proliferation and reduced puddling. Neither the date of sowing rice nor weed management practices in blackgram influenced bulk density and water stable aggregates values significantly. Moreover, biological properties such as microbial population, microbial biomass carbon and dehydrogenase activity showed a marked increase under the system involving early sowing i.e. one week before onset of monsoon and DSR and found statistically at par with NPTR.