Effect of integrated nutrient management on yield and soil microbial population in garlic

Abstract

A field experiment was conducted at Horticultural Research Station, Nanjanadu farm Ooty to study the effect of Integrated Nutrient Management on yield and the soil microbial populations in garlic. The experiment was carried out ina Randomized Blocks Design with 9 treatments and three replications. The plot size of 12 m2 was laid out. The experiment was conducted for three years from 2011 -13 and the pooled data was analysed. Pooled analysis was done for the three-harvest data (2011, 2012, 2013). All the organic manures like farm Yard Manure (FYM), Vermicompost (VC) and Poultry Manure (PM) and biofertilizers viz., Azospirillum and Phosphorus Solubilizing Bacteria each @ 5 kg each/ ha was applied as a basal as per the treatment. 50 % of the recommended inorganic applied as basal at the time of planting and the remaining 50 % N was applied in two equal splits during 30 and 45 days after planting. The full dose of P, K and S applied at the time of planting as per the treatment schedule. The treatments received three levels of FYM (15, 7.5,5 t -1/ha), Poultry Manure (7.5,3.75,2.5 t -1/ha) and Vermi Compost (7.5,3.75,2.5 t-1/ha). Observations are recorded on no. of leaves, Equatorial Diameter (ED), Polar Diameter (PD), Average Bulb Weight (ABW), A-grade bulbs (AGB), B grade bulbs (BGB), C grade bulbs (CGB), Marketable yield (MY) and Total yield (TY). Soil samples were collected at two stages (bulbing and at harvest) for microbial populations of total bacteria, fungi and actinomycetes. Results were compared among the treatments for total yield of garlic. Results revealed that the highest total as well as marketable yield was recorded in T 9 (75:40:40:40 Kg NPKS + 5 t FYM / ha + 2.5 t PM + 2.5 t VC/ ha) and T6 (75:40:40:40 Kg NPKS + 7.5 t FYM / ha + 3.75 t PM/ ha). Among the nine treatments significantly the maximum plant height (68.65 cm), the number of leaves (8.17), neck thickness (3.47 cm), polar diameter (40.03 mm), equatorial diameter (36.83cm), the average weight of 10 bulbs (203.34 g). B grade bulbs (51. 27 %), minimum C grade bulbs (16. 11%), marketable yield (8.52 tonnes/ ha), total yield (10.61 tonnes/ ha) was recorded in the T9 followed by T6 (9.72 tonnes /ha). The population of bacteria, fungi and actinomycetes were found to be maximum at the harvesting stage when compared to the bulbing stage under treatment T9.