Studies reporting agricultural greenhouse gas (GHG) emission data from tropical upland crops or the climate adaptation and mitigation potential of farming practices that involve nutrient management and/or organic farming are very limited in number. We developed alternate groundnut (Arachis hypogaea L.) farming practices for rainfed kharif (South-west monsoon) and irrigated rabi (winter) cropping seasons for agro-ecological region 3.0 in semi-arid peninsular India; and compared their yields, farm income as well as nitrous oxide (N2O) emissions with current baseline practices among regional small scale farm-holders. At the study farm, alternate practices including application of locally prepared fermented manures along with a 40-60 % reduction in application of total N increased pod yield by 50 and 35 % and net profit by similar to 120 and similar to 70 % in a drought-hit kharif and an irrigated rabi, respectively. High resolution field measurements of N2O flux indicate that the seasonal emission factors for groundnut cultivation using baseline and alternate practices were 1.7-2.0 % of applied N. Thus, the average IPCC and Indian national emissions factors of 1 and 0.58 %, respectively, underestimate GHG emissions during groundnut cultivation. Crucially, alternate practices led to (1) a reduction of 0.13 +/- A 0.07 and 0.24 +/- A 0.1 tCO(2)e ha(-1) season(-1) through decreases in direct N2O emissions along with a 50 % reduction in GHG emission intensity (per unit yield) in both seasons; (2) a concomitant average reduction of similar to 0.1 and 0.24 tCO(2)e ha(-1) season(-1) through decreased demand for manufactured fertilizers in kharif and rabi seasons, respectively. The positive implications for climate resilience, mitigation and ecosystem services are discussed.
Kritee, K; Nair, D; Tiwari, R; Rudek, J; Ahuja, R; Adhya, T; Loecke, T; Hamburg, S; Tetaert, F; Reddy, S; Dava, O
Groundnut cultivation in semi-arid peninsular India for yield scaled nitrous oxide emission reduction
Nutrient Cycling In Agroecosystems