Long-term organic and inorganic fertilization on economics, energy budgeting and carbon footprint of soybean-wheat cropping system in the Indian mid-Himalayas

ABSTRACT

For identification and adoption of improved and environmental friendly agricultural practices with minimum emission of greenhouse gases (GHGs), observations were recorded for 3 years (2015–17) in a 22-year-old soybean-wheat based long-term fertilizer experiment that was started in 1995–96. The study involved seven treatments: control (CK), organic manure (M), inorganic fertilizers (NPK), integrated (MNPK), only nitrogen (N), mineral fertilizers in both season (NPK+NPK) and nitrogen with organic manure (MN). MNPK significantly enhanced the system productivity (9.72 Mg ha⁻¹) with higher net return (3128 US$ha⁻¹) and benefit-cost ratio (1.64). Due to better energy output to inputs relation, total energy productivity and energy use efficiency were reported higher in MNPK (0.38 kg MJ⁻¹ and 4.76, respectively) followed by MN (0.34 kg MJ⁻¹ and 4.26, respectively) and M (0.32 kg MJ⁻¹ and 4.16, respectively). In contrast to C efficiency, C sustainability index and yield scaled carbon footprint (CFy), the spatial CO₂-e emission (CFs) was found highest under MNPK (~5035 kg CO₂-e ha⁻¹) followed by MN and NPK+NPK and lowest was recorded under control. In sum, long-term organic and inorganic fertilization simultaneously in soybean-wheat system may be a preferred strategy for improving soil productivity, profitability, energy use and environmental sustainability of Indian-mid-Himalayas.

KEYWORDS:

• Soybean-wheat
• system productivity
• carbon footprint
• energy use efficiency
• benefit/cost ratio (B:C ratio)

Disclosure statement

No potential conflict of interest was reported by the author(s).