Effect of green organic mulching and nitrogen management on productivity, N use efficiency and profitability of Basmati aerobic rice (Oryza sativa)

Abstract

A field experiment was conducted in kharif seasons of 2013 and 2014 at ICAR-IARI, New Delhi to study the effect of green organic mulching and nitrogen (N) management on crop productivity, N-use efficiency and economics of aerobic rice (Oryza sativa L.). The experiment was laid out in split plot design with residue management practices assigned to main plots, and N management treatments allocated in sub plots and replicated thrice. Results revealed that with green mulching all yield attributes, viz. effective tillers, panicle length, panicle weight and 1000-grain weight were significantly higher in transplanted rice (TPR) than other treatments. N management at 100% recommended dose of N (RDN) + Azotobacter recorded the highest values of all the yield attributes and those were at par with 100% RDN. Highest grain (3.95 and 3.73 t/ha), straw and biological yield were obtained with TPR treatment. Similarly, N management with mineral fertilizer and Azotobacter biofertilizer significantly enhanced the grain, straw and biological yields and highest the grain (4.29 and 3.44 t/ha), straw and biological yield was recorded with 100% RDN + Liquid Azotobacter. The uptake of N in grain, straw and its total were highest with TPR during both the years. Among the N management treatments, maximum N-uptake were recorded with 100% RDN + Azotobacter in grain (58.0 and 47.4 kg/ha) and straw (47.9 and 41.9 kg/ha). Data pertaining to nitrogen use efficiencies (agronomic and crop recovery efficiency) were positively influenced with residue application and N management. The highest value of agronomic (15.2 and 11.7 kg grain increased/kg N applied) efficiency and crop recovery (43.9 and 37.9 %) efficiency were observed with 100% RDN + Azotobacter during both the year of experiment. The cost of cultivation was highest under TPR (rs` 48.79 × 103 and 56.04×103) which was followed by Leucaena and Sesbania treatments. In case of N management, cost of cultivation was highest in 100% RDN +Azotobacter (` 42.14 × 103 and 49.07 × 103) which was closely followed by 100% RDN during both the years. The maximum gross return (`rs 122.2 × 103 and 116.0 × 103) and net return (` 73.4 × 103 and 59.9 × 103) were recorded in TPR. However, in N management 100% RDN + Azotobacter gave highest gross (`rs132.7 × 103 and 107.1×103) and net return (`rs 90.5 × 103 and 58.0 × 103) and it was followed by 100% RDN.