Rakesh SharmaOjaswini2024-07-252024-07-252024-07-06https://krishikosh.egranth.ac.in/handle/1/5810212507The present study aimed to investigate the effect of different bio -organic nutrient sources on soil properties and yield of onion (Allium cepa L.) in sub-tropics of Himachal Pradesh and was carried out during rabi 2022-23 at the experimental farm of Department of Soil Science and Water Management, College of Horticulture and Forestry, Neri, Hamirpur. The experiment was laid out with nine treatments in a randomized block design, each replicated thrice. The treatments included: T 1 = Beejamrit + Jeevamrit @ 5 % at weekly interval, T2 = FYM @ 25 t ha-1 + R.D.F (recommended practice of manure and fertilizers), T 3 = FYM @ 25 t ha-1 + Beejamrit + Jeevamrit @ 5 % at weekly interval, T 4 = FYM @ 25 t ha-1 + Beejamrit + Jeevamrit @ 5 % at fortnight interval, T 5 = Vermicompost @ 10 t ha-1 + R.D.F, T6 = Vermicompost @ 10 t ha-1 + Beejamrit + Jeevamrit @ 5 % at weekly interval, T 7 = Vermicompost @ 10 t ha-1 + Beejamrit + Jeevamrit @ 5 % at fortnight interval, T8 = Ghanjeevamrit @ 5t ha-1 + Beejamrit + Jeevamrit @ 5% at fortnight interval and T 9 = 100 per cent R.D.F where, R.D.F was recommended dose of fertilizers (NPK = 120:75:60 kg ha-1). Results of the investigation revealed that treatment T 6 recorded maximum onion growth, yield, quality parameters along with nutrient uptake by the crop and outperformed the treatment T 2 (recommended dose of manure and fertilizers). Treatment T 6 also observed 9.63 per cent increment in bulb yield per hectare over treatment T2, coupled with the highest (2.43) benefit: cost ratio. Further, there was a significant effect of different nutrient sources on various soil properties. The maximum soil water holding capacity, soil organic carbon, available N,P, K, S and DTPA-extractable micronutrients (Fe, Cu, Zn and Mn) content were observed under treatment T 3. Treatment T3 also recorded a significant increase in biological properties such as total microbial population, total fungal population, nitrogen-fixing bacteria, phosphate solubilizing bacteria, microbial biomass carbon, microbial biomass nitrogen, soil respiration, alkaline phosphomonoesterase, and dehydrogenase activity which indicated the pivotal role of soil properties for the nutrient dynamics and availability to the crop. A positive and significant relationship of bulb yield was observed with plant height, number of leaves, bulb diameter, total soluble solids, total N, P, K and S uptake. Plant available nitrogen, phosphorus, potassium, sulphur, total viable microbial population, total fungal population, microbial biomass carbon, microbial biomass nitrogen, soilrespiration, alkaline phosphomonoesterase and dehydrogenase activity demonstrated the positive and significant relationship with onion bulb yield. Thus, the results concluded that jeevamrit @ 5 per cent at weekly intervals in conjuction with FYM, vermicompost and ghanjeevamrit revealed superior results for growth, yield, quality parameters of onion and also improved the soil properties over combined application of RDF with FYM and vermicompost.EnglishThesis