Post-harvest soil health of wetland rice ecosystem as influenced by spatial arrangements and integrated nutrient management

A field experiment was conducted at Annamalai University Experimental Farm, Department of Agronomy, Annamalai University, Annamalainagar to study the effect of spatial arrangements and integrated use of green leaf manure with inorganic nutrition on soil fertility and microbial population of post harvest soil of wetland rice. The results revealed that the spatial arrangements and integrated nutrient management were significantly influenced the post harvest soil health and microbial population. Among the treatment combinations, spot seeding of rice at 30 ´ 30 cm spacing for Thaladi and 25 ´ 25 cm spacing for Navarai season under the integrated application of 50 per cent N via., Albizia lebbeck along with 50 per cent N via., inorganic fertilizer significantly improved the post harvest soil available N (268.51and 244.56 kg ha-1), P2O5 (23.89and 24.67 kg ha-1) and K2O (382.92and 337.04 kg ha-1) during the Thaladi and Navarai seasons, respectively. The same trend was also recorded in the soil microbial population of bacteria (58.78 and 46.33 x 10-6 g-1 of soil), fungi (39.78 and 34.00 x 10-4 g-1 of soil) and actinomycetes (8.00 x 10-6 g-1 of soil), respectively.