Climate resilient integrated soil-crop management (CRISCM) for salt affected wheat agri-food production systems.

Abstract

Maximizing opportunities for climate resilient agriculture is vital for global food security, and ecological sustainability. To explore the improvement potential of mitigation and adaptation strategies in stabilizing wheat production and increasing farm income in sodicity-prone Ghaghar Basin of Haryana, India, participatory research trials on land reclamation (gypsum/pressmud) and crop management (varieties, nutrient management and weed control) practices were undertaken during 2016-2020. Results indicated that combining gypsum and pressmud together accelerated the reclamation process (soil pH: -3.3% and ESP: -22.1%) and improved plant adaptability (RWC: 10%; MI: -15%; Pn: 40%; gS: 36%; NaK_S: -38% and NaK_R: -42%), which in turn increased wheat yield by 20% compared to unamended control. With increasing sodicity stress, salt tolerant wheat variety KRL 210 exhibited better morpho-physiological adaptation, lesser yield reduction (0.8-1.1 t ha-1) and attained 4.1% mean yield advantage compared to traditionally cultivated HD 2967. There were genotypic differences for N requirements in sodicity stressed wheat, with 173 kg ha-1 in KRL 210 and 188 kg ha-1 in HD 2967 as the economically optimum dose; further advocating for upward revision of current N recommendations beyond 150 kg N ha-1. Balanced nutrition through foliage applied K compensated the sodicity hazards with lower proportion of Na+/K+ in leaf tissues (13%), and attained higher grain yield (4%) and incremental income (34 US$ ha-1) compared to farmers' practice. Sequential use of herbicides provided affordable solution to check Phalaris minor infestation (84% WCE) and enhanced wheat productivity (5.7% higher) with incremental income of 48 US$ ha-1 compared to farmers' sole dependency on post-emergence herbicides. Synergistic integration of gypsum and pressmud-mediated sodic land reclamation, usage of stress tolerant wheat variety, 15% higher N application, foliar K-nutrition and effective P. minor control substantiate appreciable reduction in soil sodicity, improved crop resilience, and ultimately translated into 5% and 26% higher yields over the recommended and local farm practices, respectively. The key insights of this study suggest a range of opportunities wherein inputs of CRISCM could potentially stabilize the wheat production, improve farm economy and reduce environmental risks beyond what is currently being achieved with existing farm practices.