Integrated nutrient management on oat-grasspea intercropping system: An evaluation of system productivity, economics, energetics and carbon footprint

Abstract A field investigation was conducted at Central Research Farm of Bidhan Chandra Krishi Viswavidyalaya, West Bengal, India during winter seasons of 2020-21 and 2021-22 with the aim to evaluate system productivity, economics, energetics and carbon footprint (CF) of oat-grasspea intercropping systems under different integrated nutrient managements (INM). The experiment was laid out in split-plot design with 4 cropping systems in main plots and 4 levels of nutrient management in sub plots. Sole grasspea cultivation stood best in terms of system productivity, economics, energetics and environment safety by low CF. Moreover, INM involving 75% N through urea + rest N through vermicompost registered significantly higher system productivity (15.49 q ha-1) in case of 3:3 oat+ grasspea intercropping system (CS4N3). Further, this intercropping system registered high economic profitability (net return: US$ 430.4 ha-1, B:C- 1.71) as well as energy indices (energy output: 71179.1 MJ ha-1, net energy gain: 60352.0 MJ ha-1, energy ratio: 6.57 and energy profitability: 5.57). CF was also found relatively less under CS4N3 (Yield scaled CF: 75.3 kg CO2-e q-1). High carbon efficiency (7.92) and carbon sustainability index (6.92) were also recorded by CS4N3 as it produced maximum carbon output (1801.2 kg ha-1). Overall, 3:3 oat+ grasspea intercropping system can be cultivated by the cereal and legume growers of India under intensive cropping scenario using 75% N through urea + rest N through vermicompost as INM option.