Quantitative Dissection of Salt Tolerance for Sustainable Wheat Production in Sodic Agro-Ecosystems through Farmers’ Participatory Approach: An Indian Experience

Abstract

To explore the comparative effects of field sodicity (soil pH) and irrigation water residual alkalinity (RSCiw) on physiological and biochemical attributes of salt tolerance, and crop performance of two wheat varieties (KRL 210, HD 2967), a total of 308 on-farm trials were carried out in sodicity affected Ghaghar Basin of Haryana, India. Salt tolerant variety KRL 210 maintained relatively higher leaf relative water content (RWC; 1.9%), photosynthetic rate (Pn; 5.1%), stomatal conductance (gS; 6.6%), and transpiration (E; 4.1%) with lower membrane injury (MII; −8.5%), and better control on accumulation of free proline (P; −18.4%), Na+/K+ in shoot (NaK_S; −23.1%) and root (NaK_R; −18.7%) portion compared to traditional HD 2967. Altered physiological response suppressed important yield-related traits revealing repressive effects of sodicity stress on wheat yields; albeit to a lesser extent in KRL 210 with each gradual increase in soil pH (0.77–1.10 t ha−1) and RSCiw (0.29–0.33 t ha−1). HD 2967 significantly outyielded KRL 210 only at soil pH ≤ 8.2 and RSCiw ≤ 2.5 me L−1. By comparisons, substantial improvements in salt tolerance potential of KRL 210 with increasing sodicity stress compensated in attaining significantly higher yields as and when soil pH becomes >8.7 and RSCiw > 4 me L−1. Designing such variety-oriented threshold limits of sodicity tolerance in wheat will help address the challenge to enhance crop resilience, closing the yield gaps and improve rural livelihood under the existing or predicted levels of salt stress.

Combining Hyperspectral Reflectance and Multivariate Regression Models to Estimate Plant Biomass of Advanced Spring Wheat Lines in Diverse Phenological Stages under Salinity Conditions

“…Additionally, approximately 1.5 Mha of arable land is degraded annually by salt accumulation, with the main cause being the improper application of several agricultural activities including intensive agriculture and heavy application of fertilizers [4][5][6]. If the degradation of arable land continues at this rate, soil salinization will lead to the degradation of an estimated 50% of the world's agricultural land by 2050 [7]. Furthermore, salinization of agricultural soil causes approximately 50% of potential yield losses and up to $27.5 billion of economic losses annually [8].…”

Ability of Different Growth Indicators to Detect Salt Tolerance of Advanced Spring Wheat Lines Grown in Real Field Conditions

“…However, these practices can be costly and require expertise, particularly when implemented on a large scale. Previous studies have concurred that providing farmers with salt-tolerant genotypes is a feasible and effective strategy for addressing salinity in agriculture and achieving reasonable yields [ 8 , 11 , 12 , 13 ]. Despite the research community’s great efforts to enhance the salinity tolerance of wheat genotypes, the number of salt-tolerant genotypes worldwide remains very limited.…”

Halophytes as new model plant species for salt tolerance strategies

“…However, salt tolerance in the plant kingdom is much more than just a scientific curiosity since most of our crop species fall into the “sensitive” category, and the areas suitable for their cultivation are shrinking day by day as a result of increased desertification and salinization. Although many salt-tolerant varieties are being cultivated over different regions and various climate-resilient management strategies have been proposed for different ecosystems ( Sheoran et al., 2021b ; Sheoran et al., 2022 ), consequently, understanding the eco-physiological mechanisms and the biogeography and ecology of salt tolerance in higher plants and their associated microorganisms is a vital step toward generating salt-tolerant plant types. The use of potential halophytes in phytoremediation of salt-affected areas and in the ecological restoration and rehabilitation of degraded ecosystems may emerge as being, or more, important than biosaline agriculture itself, and halophytes are being explored for desalination of saline lands.…”