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We assessed the improvement potential of pressmud – a sugar industry waste – on soil properties, physiological adaptation and yield‐related traits in a rice–wheat rotation in sodicity‐affected Ghaghar basin of Haryana, India. Large‐scale (0.2–0.4 ha) participatory trials comprising two treatments, with (+PM) and without (–PM) pressmud, were conducted on 125 farmers' fields covering non‐sodic (NS), slightly sodic (SS) and moderately sodic (MS) soils. Pressmud application (10 Mg ha−1) led to appreciable reductions in soil pH (1.6–3.6%) and exchangeable sodium percentage (ESP; 10.4–20.1%) with concomitant improvements in plant physiological and yield‐related traits across different soil alkali classes, albeit to a greater extent in SS and MS soils than in NS soils. Compared to prevailing farmers' practices (–PM), transformative improvements in mean leaf relative water content (RWC) (4 and 7%), membrane injury (MII) (−12 and −14%), photosynthetic rate (Pn) (21 and 25%), stomatal conductance (gS) (26 and 21%), transpiration rate (E) (38 and 22%), proline (P) (−19 and −20%) and Na+/K+ accumulation in shoot (NaK_S) (−24 and −22%) and root (NaK_R) (−23 and −27%) were observed in both rice and wheat grown under PM ameliorated soils. On an average, rice and wheat yields were increased by 15.8 and 14.6% in SS and 18.9 and 16.7% in MS soils, respectively, with pressmud application. Principal Component Analysis (PCA) showed significant correlations among highly weighted variables including physiological and yield‐related traits to influence the rice–wheat productivity with PM addition in SS and MS soils. Sustained use of this organic waste in agricultural lands seems to be an affordable solution for overcoming sodicity‐induced land degradation, and achieving developmental goals of environmental and livelihood security. [ABSTRACT FROM AUTHOR]

• Participatory research ensured better technology packaging, validation and adoption. • Gypsum and pressmud–mediated land reclamation better alleviates sodicity stress. • Denser planting and additional N improved crop resilience and yield in sodic areas. • Improved genetic tolerance and agronomic management bridged yield gaps and enhanced farmers' income. Regaining the agricultural potential of salt–affected lands offers an opportunity of production enhancement and sustaining food security in less favourable environments. This study aims at deciphering the synergy of adaptive and mitigation strategies– using salt tolerant rice varieties with affordable land reclamation and crop management options. The study was conducted following farmers' participatory approach for 3 years (2017–19) in sodicity–affected Ghaghar Basin of Haryana, India. Compared with the locally adapted variety PB1121, using the salt tolerant Basmati CSR30 resulted in less yield reduction and better returns, providing better opportunities for stabilizing crop production, and enhancing resilience and adaptation in sodic soils irrigated with alkali water. Gypsum and pressmud–mediated land reclamation reduced soil sodicity, improved salt tolerance and increased yield by ∼35 % compared to the control (2.19 t ha–1). Transplanting two seedlings per hill at 20 × 15 cm spacing resulted in better crop establishment and plant stand, with consequent increase in yield and economic gains over the farmers' practice of randomly transplanting one seedling hill–1. The significant increase in yields with addition of ∼25 % more N confirmed the farmers' perception of using more N in sodic soils, suggesting the need for revising existing recommendations. Curve Expert model revealed genotypic variation in N requirements, with 90 kg N ha–1 for CSR30 and 140 kg N ha–1 for PB1121 as economically optimum in sodic soils. Transformative improvements involving the use of adapted stress–tolerant varieties with location–specific agronomic practices increased yield by 6% over the existing recommendations and by 24 % over farmer's practices; showing potential for bridging the rice yield gaps, halting salt–induced land degradation and improving rural livelihood in salt–affected areas. [ABSTRACT FROM AUTHOR]

Farm level recommendation in salt-affected agricultural landscapes is practically difficult due to spatial variations in inherent soil salinity, diverse farming situations and associated land ownerships with small-scale production systems. This study presents spatial array analysis of 354 geo-referenced soil samples revealing widespread heterogeneity in soil sodicity and fertility status across salt-affected Ghaghar basin of Kaithal district in Haryana, India. Six principal components accounted for 73% of the total variability, and the most important contributors [electrical conductivity (EC e), sodium adsorption ratio (SAR), DTPA extractable copper (Cu) and boron (B), soil organic carbon (OC) and available phosphorus (AP)] as minimum data set were used to develop the soil quality index (SQI). Geostatistical analysis revealed Circular (EC e and AP), Exponential (SAR, OC and B) and Gaussian (Cu) as the best fit semivariogram ordinary kriging model with weak to moderate spatial dependence. Three soil management zones (SMZs) were delineated by grouping the entire area based on soil quality index (SQI). Fertilizer recommendations for rice-wheat cropping system in different SMZs were calculated using soil test crop response (STCR) equation to ensure balanced fertilization, resource saving and reducing environmental footprints. Gypsum requirement map was prepared for systematic allocation and distribution, and enabling farmers to precisely use the mineral gypsum in order to reclaim and reduce stresses led by sodic lands. The implications of this study showed zone-specific advocacy for gypsum application (as soil ameliorant) and balanced fertilization in sustainable restoration of sodic lands, improving nutrient use efficiency and stabilizing crop production in salt-affected regions of India and similar ecologies elsewhere. [Display omitted] • Principal soil parameters identified for periodic monitoring and characterization of salt-affected soils. • Inconsistent distribution pattern of soil properties was observed in semivariogram. • Soil quality index was used to delineate the soil management zones. • Zone-wise gypsum requirement and fertilizer scheduling addressed resource optimization and ecosystem sustainability. [ABSTRACT FROM AUTHOR]