Effect of Bio-fertilizers and Organic Amendments on Nutrient Uptake and Soil Microbial Population of Pummelo Seedlings (Citrus maxima L) under Nursery Condition

Abstract

An experimental was carried out at Regional Horticultural Research and Extension Centre (RHREC), University of Horticultural sciences campus, GKVK, post Bangaluru-560065, during the year 2019 – 20). The nursery was established in potting mixture; sand, soil and farm yard manure in the ratio of 2:1:1 (Sand: Soil: FYM;) taken in polythene bags of size 12 cm x 24 cm. Applied with bio-fertilizers such as Azospirillum spp., Phosphorus solubilizing bacteria (PSB), Pseudomonas flourescens and Vesicular Arbuscular Mycorrhiza (VAM)@ 6 g per plant soil based bio-fertilizers. Organic amendments such as Panchagavya, Jeevamrutha, Beejamrutha and bio-digested liquid were tested at 5 and 10 per cent (applied through foliar application at 30 days interval). A total of nine treatments were tested in four replications. The results at the end of 120 days showed that the combination of four bio-fertilizers; Azospirillum, Phosphorus solubilizing bacteria, Pseudomonas flourescens and VAM had highest Nitrogen per plant (0.636 g) (T5). However T3 treatment had maximum Phosphorus (0.055 g/plant) and Potassium (0.150 g/plant) with inoculation of Azospirillum + PSB+VAM. The maximum bacterial population (4.40 CFU X 104g-1soil) was found in the treatment Azospirillum spp. + PSB +PF + VAM (T5), followed by T3 (3.75 CFU X 104g-1 soil). The highest fungal population (2.60 CFU X 104g-1soil) was noticed in the treatment Azospirillum spp. + PSB) + VAM (T2), followed by T5 (2.55 CFU X 104g-1soil), the minimum NPK and microbial population was recorded in control treatment at the end of 120 days in nursery.