Performance of Nano- DAP under Rice-Wheat Cropping System in Vertisol of Chhattisgarh, India

A field experiment was carried out in research farm, IGKV, Raipur, Chhattisgarh, India during Rabi 2020-2021 and Kharif 2021-22 under rice- wheat cropping system at Research Farm, College of Agriculture, Raipur, (IGKV). The experiment was laid out with 12 treatments of rice and wheat in randomized block design. Treatments of rice in Kharif season includes (T1) Absolute Control (N0:P0:K0), (T2) 0% P (Control P0); (NPK @ 120:0:40), (T3) 100% P through DAP (NPK @ RDF 120:60:40), (T4) 75% P through DAP (NPK @120:45:40), (T5) 50% P through DAP (NPK @120:30:40), (T6) T4 + Root Dipping @ 5 ml /L + Foliar Spray @ 2 ml/ L at 30 DAT with Nano DAP, (T7) T4 + Root Dipping @ 5 ml /L + Foliar Spray @ 4 ml/ L at 30 DAT with Nano DAP, (T8) T5 + Root Dipping @ 5 ml /L + Foliar Spray @ 2 ml/ L at 30 DAT with Nano DAP, (T9) T5 + Root Dipping @ 5 ml /L + Foliar Spray @ 4 ml/ L at 30 DAT with Nano DAP, (T10) T5 + Root Dipping @ 5 ml / L + Foliar Spray @ 2 ml / L at 25 and 45 DAT with Nano DAP, (T11) T5 + Root Dipping @ 5 ml / L + Foliar Spray @ 4 ml / L at 25 and 45 DAT with Nano DAP and (T12) T5 + Seed Treatment @ 5 ml / kg seed + Foliar Spray @ 4 ml / L at 30 DAT with Nano DAP. In rice the results of soil microbial biomass carbon showed that higher values were recorded in treatments with 100 % P through DAP. Results of fungus reveals that 100 % and 75 % P through DAP obtained significantly higher soil fungus colony count. The results of total bacteria showed that 100 %, 75 % P through DAP and T4 + Root Dipping @ 5 ml /L + Foliar Spray @ 2 and 4 ml/ L at 30 DAT with Nano DAP obtained significantly higher soil total bacteria. The results of PSB reveals that 50% P through DAP and treatments in combination with 50% P through DAP and Nano-DAP obtained significantly higher phosphorus solubilizing bacteria.