Effect of biofertilizers on soil microbial count, nutrient availability and uptake under november sown onion

Abstract

Biofertilizers improves the soil microbial content, Soil nutrient status and nutrient uptake by plant. In an experiment, fifteen treatments comprised of various combinations of biofertilizers, organic manures and chemical fertilizers were compared to access the impact of different sources of nutrient on performance of onion. The highest soil organic carbon (0.40%) was observed in the treatments T12 (Farm Yard Manure (FYM) @ 20 t/ha) and T11 (FYM myctes count (29.9 X 104) was recorded in T11 (FYM @ 20 t/ha + Azotobacter + VAM) treatment while highest fungal @ 20 t/ha + Azotobacter + Vesicular-Arbuscular Mycorrhizae (VAM)). Highest bacterial (24.5 X 106) and actino-count (17.5 X 103) was observed in T3 (Azospirillium+ Recommended dose of NPK) treatment. At the time of harvesting, available nitrogen (N), available phosphorus (P) and available potassium (K) were higher in treatment T3 (Azospirillium + Recommended dose of NPK), T9 (Azotobacter+ VAM + Recommended dose of NPK) and T13 (Poultry treatment (162.6 Kg ha-1) as compared to all other treatments except T1 and T9 treatments while P uptake (13.6 Kg ha-Manure @ 5t/ha) treatments respectively than that in other treatments. Azospirillum and Azotobacter application along with recommended dose of N, P and K improved the fertility status of soil. The N uptake was significantly higher in T3 treatments. The present study highlights the need of use of biofertilizers along with organic and inorganic 1) was significantly higher in T9 treatment than that in other treatments except T1, T3, T5 and T7 treatments. The K uptake was significantly higher in T3 treatment (126.9 Kg ha-1) as compare to all other treatments except T1 and T9 manures/fertilizer to enhance the nutrient availability and improve soil health.