Enzyme Activity and Rhizosphere Microflora under Sugarcane Monocropping as Influenced by Integrated Nutrient Management

Ch S Rama Lakshmi,A Sireesha,T Sreelatha,P Jamuna ,M Bharatha Lakshmi

doi:10.12944/carj.7.3.10

Abstract

Sugarcane is one of the lead crops in North Coastal Andhra Pradesh. Farmers in North Coastal Zone are opting for raising more number of ratoons owing to its substantially low cost of production. Ratoon crops however seldom receive proper care and inputs due to considered it as a bonus crop by majority of farmers. Field experiments were conducted consecutively for six years in the same field (2012-13 to 2018-19) at RARS, Anakapalle to study the monocropping effect on soil biology under the influence of different nutrient management practices. Irrespective of the year of ratooning, plots which received 50% recommended dose of chemical fertilizers + 25% nitrogen though vermicompost + 25% nitrogen through green manure incorporation resulted in higher microbial population over chemical fertilizers alone. Activity of dehydrogenase and active carbon pool also showed similar trend in multi-ratooning system of sugarcane. Rhizosphere microbial population at different growth stages revealed that, azospirillum population was observed highest followed by azotobacter while lowest population counts of phosphorus solubilizing bacteria were observed. Highest population counts were recorded in INM plots and population was highest at formative later reduced to harvest. INM with 50% RDFN + 50% through organics (66.80 t ha-1) recorded at par yields with 100% RDF (67.28 t ha-1).

Highlights

Sugarcane (Saccharum officinarum L.) is one of the most important cash crops in India and plays pivotal role in both agricultural and industrial economy of our country
Among different treatments highest dehydrogenase activity was recorded in treatments which received integrated nutrient sources over chemical fertilizers alone at all the crop growth stages
Rhizosphere Microbial Population Data on nitrogen fixers revealed that, Azosprillium population was more than azatobacter population at different growth stages and it was observed that microbial population was gradually increased to formative and decreased to grand growth in all the treatments

Summary

Introduction

Sugarcane (Saccharum officinarum L.) is one of the most important cash crops in India and plays pivotal role in both agricultural and industrial economy of our country. Seldom receive proper care and inputs due to being considered a free crop by majority of farmers poor in resources Such a approach for a long duration production system, often leads to significant deterioration in soil health (Singh et al, 2007). Indiscriminate use of mineral nutrients and continuous use of higher doses of chemical fertilizers on the other hand raises the cost of production so high that renders the system unprofitable.[7] Sugarcane crop produces a heavy tonnage and tends to remove substantial quantum of plant nutrients from the soil. Slow release of nutrients from organics, could help a long duration sugarcane crop to take their complete benefit Keeping in this view, present study on effect of different integrated nutrient management practices on soil biology under sugarcane multiratooning was undertaken up

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Conclusion