Effect of NPK through Chemical Fertilizers Combination with Farm Yard Manure (FYM) and Bio-fertilizers on Yield Attributes of Onion (Allium cepa L.) in Jaipur Region of Rajasthan, India

The field experiment was conducted in loamy sand soil of the Horticulture farm, Vivekanand Global University Jaipur, during Rabi season of 2020-21 and 2021-22. The experiment comprises of 32 treatment combinations replicated three times was laid out in split-plot design (SPD) with four fertility levels of NPK (0, 50, 75 and 100% of recommended dose of NPK) and two levels of FYM (without FYM and with FYM @ 25 t ha-1) were added in main plots. Four bio-fertilizer levels (No inculcation, N2 fixer Azotobacter, PSB inculcation and N2 fixer Azotobacter + PSB inoculation) were added in sub plots. The treatments comprised of Chemical fertilizers, FYM and biofertilizers with ten treatments Viz., F0- Control, F1-50% of recommended dose of NPK, F2-75% of recommended dose of NPK, F3-100% of recommended dose of NPK, M0- Without FYM, M1- With FYM @ 25 t ha -1, B0- No inoculation, B1- N2 fixer Azotobacter, B2- PSB inoculation and B3- N2 Fixer Azotobacter + PSB inoculation, respectively. The results of the study have clearly shown that application of chemical fertilizer up to 100% RDF increased the entire yield and its attributes viz. (neck length, bulb diameter, number of scales, fresh weight of bulb, volume of bulb). With application of FYM @ 25 t ha-1 yield significantly improved    with its attributes. Use of biofertilizers (N2 fixers Azotobacter + PSB inoculation) in combination or alone increased all yield and its attributes. Integrated system approach is not only the liable for attaining fairly high productivity with substantial fertilizer economy but also a concept of soundness leading to sustainable agriculture .