Vol. 12, Issue 3 (2023)

Author(s):
Roshni John, Thulasi V, Sandeep S, Smitha John K, Beena VI and K Surendra Gopal

Abstract:
The present investigation was carried out at RARS, Pattambi, Kerala during 2020-2021 on continuous application of manures and fertilizers under rice-rice cropping system since 1997. The experiment consists of twelve treatments with four replications viz., : T₁: 50 percent NPK, T₂ : 100 percent NPK, T₃ : 150 percent NPK, T₄ : 100 percent NPK + 600 kg ha^-1 CaCO₃, T₅ : 100 percent NPK, T₆ : 100 percent NP, T₇ : 100 percent N, T₈: 100 percent NPK + FYM @ 5 t ha^-1, T₉: 50 percent NPK + FYM @ 5 t ha^-1, T₁₀ : 100 percent NPK + in situ growing of Sesbania aculeate, T₁₁ : 50 percent NPK + in situ growing of Sesbania aculeata) and T₁₂ : Absolute control (No fertilizers or manures). The effect of treatments on microbial population and yield of crop confirmed integrated nutrient management as the best treatment in enhancing the soil biological properties. Results showed that the population of bacteria, fungi and actinomycetes was highest in T₈ (100% NPK + FYM). Seed yield and straw yield was also found to be highest in the T₈ which was on par with T₁₀.