Journal of Environmental Biology

Energy input-output relationship of soybean-based cropping systems under different nutrient supply options

K. Prajapat¹*, A.K. Vyas², S. Dhar³, N.K. Jain², Mohd. Hashim⁴ and G.L. Choudhary⁵

¹ICAR-Indian Institute of Wheat and Barley Research, Karnal-132 001, India

²Indian Council of Agricultural Research,? New Delhi-110 012, India

³ICAR-Indian Agricultural Research Institute, New Delhi-110 012, India

⁴ICAR-Indian Agricultural Research Institute, RS-Pusa-848 112, India

⁵Bihar Agricultural University, Sabour-813 210, India

*Corresponding Author E-mail: kp.agron@gmail.com

Key words

Cropping systems

Carbon balance

Carbon flux

Energy use efficiency

Nutrient supply options

Publication Data

Paper received : 06.09.2016?????????????????? Revised received : 10.05.2017????????????????????? Re-revised received : 18.05.2017 Accepted : 24.06.2017???????? ??

Abstract

Aim: Increase in agricultural productivity with minimal energy utilization without any adverse impact on the environment is a pre-requisite of present agricultural practices through best agronomic management of crop production. The present investigation aimed to identify the most energy efficient cropping system and nutrient supply option which exert minimal impact on the environment.

Methodology: The experiment was carried out for two consecutive years at Indian Agricultural Research Institute, New Delhi for the evaluation of soybean-based cropping systems with five nutrient supply options with respect to energy parameters, as well as carbon emission equivalents. The different inputs used in raising the crops and output of crops were converted into energy and carbon equivalents using standard conversion factors and used for computation of different energy and carbon efficiency indices. ????

Results: The soybean?potato?mungbean system recorded significantly highest system productivity in terms of soybean seed-equivalent yield (7.68 t ha^-1), however soybean?chickpea?fodder sorghum system recorded highest net energy (333.9 ?10³ MJ ha^-1), energy efficiency (9.56), energy productivity (179 gMJ^-1), energy profitability (8.6 MJ ha^-1), human energy profitability (105.2) and energy intensiveness (6.76). Soybean?chickpea?fodder sorghum system maintained higher carbon output and carbon efficiency which was 22.9 and 15.6% higher over soybean?wheat system, respectively. Among the nutrient supply options, application of 50% RDF + 50% RDN through FYM accounted for the highest energy output (286.1 MJ ha^-1), net energy (240.3 MJ ha^-1) and energy output efficiency (968 MJ ha^-1 day^-1) and also reduced the carbon flux to the atmosphere as compared to 100% RDF. ?????

Interpretation: The cropping system followed and sources of nutrient supply had considerable impact on utilization of energy, as well as carbon emission equivalents. Therefore, besides looking only upon productivity of a particular cropping system and management level, their relative energy efficiency and resultant impact on the environment should also be taken into consideration for ensuring judicious use of non-renewable resources.

Copyright ? 2018 Triveni Enterprises. All rights reserved. No part of the Journal can be reproduced in any form without prior permission. Responsibility regarding the authenticity of the data, and the acceptability of the conclusions enforced or derived, rest completely with the author(s).