Soil salinity and the use of saline groundwater are two major constraints in crop production, which covers a ~1.0 billion ha area of arid and semi-arid regions. The improved drainage function of soil can modify the salty growing environment for higher agricultural production. The present study evaluated the effectiveness of cut-soiler-constructed rice residue-filled preferential shallow subsurface drainage (PSSD) to improve the drainage function and its effect on the yield, quality and plant–water relations of mustard over 2019–2021. Cut-soiler-simulated drains were made in a semi-controlled lysimeter (2 × 2 × 3; L*W*H m) as the main plot treatment in a double replicated split–split experiment with two soil types (subplot) and three irrigation water salinities (4, 8 and 12 dS m⁻¹) as the sub-sub-plot treatment. The drainage volume of variable salinity (EC), dependent on the total water input, was substantially higher in the rainy season (April to October), i.e., 16.6, 7.76 and 12.0% during 2018, 2019 and 2020, with 1.7, 0.32 and 0.77 kg salt removal per lysimeter, compared to the post-rainy season. The mustard seed, straw and biological yields were improved by 31.4, 14.41 and 18.08%, respectively, due to a positive effect on plant–water relations. The mustard seeds produced in the cut-soiler-treated plots recorded higher oil, crude fiber and protein contents and a lower erucic acid content. The increase in salt load, by higher-salinity irrigation water, was also efficiently managed by using cut-soiler PSSD. It was found that the saline irrigation water up to 12.0 dS m⁻¹ can be used under such PSSD without any extra salt loading. The present study showed the potential of cut-soiler PSSD in root zone salinity management by improving drainage in salt-affected arid regions.

Agriculture in Indo-Gangetic plains (IGP) of India is facing challenges of food security, low factor productivity, lowest per capita landholding and natural resource sustainability in the changing climate. Prevalent rice-wheat system (RWS) in this region requires more labour, water and chemical inputs leading to excessive groundwater exploitation and soil degradation. Present enterprise mix diversification study was carried out to improve productivity, profitability and resource use efficiency of the smallholders in reclaimed sodic lands of IGP during 2007–2015 at ICAR-Central Soil Salinity Research Institute, Karnal, India. Total 2.0 ha area was diversified under grain, vegetable, horticulture, fodder, fisheries, livestock and poultry production systems. This system produced ∼20% higher (13.3 tha⁻¹) rice equivalent yield (REY) than RWS(11.1 tha⁻¹). This system also generated 15.3% higher eight years average net income ($ 5363), than RWS ($ 4650/-), and 875 man-days/annum employment. By recycling this system used ∼50% lesser water than RWS and also improved soil health. On farm production and availability of cereals, vegetables, fruits, milk, eggs, fish, etc. in the system also to ensure food and nutritional security of the farm family. Overall the enterprise mix diversification system enhanced agricultural sustainability with higher productivity, income, employment generation and minimized climatic hazards.

Background: The extent of natural salt-laden groundwaters used for irrigation is increasing worldwide, which is a fast-emerging threat to agroecosystems and global food security. The salt buildup in the soil is linked to deteriorated soil chemical, physical, and biological health and decreased land productivity. Alkali waters with high residual sodium carbonate (RSC) is one of the severe poor-quality waters that deteriorate soil. We evaluated soil microbial dynamics and soil health at critical growth stages of rice crop receiving two-decade-long irrigation with three levels of alkali water and two reclamation strategies. These included good-quality water (GQW), alkali water (ALKW) with an RSC concentration of 5 me L⁻¹ (ALKW1), ALKW with an RSC concentration of 10 me L⁻¹ (ALKW2), ALKW2 treated to neutralize RSC to 5 me L⁻¹ using gypsum (CaSO₄·2H₂O; ALKW2 + GYP), and ALKW2 treated with sulfuric acid (H₂SO₄; ALKW2 + SA). Eleven microbial parameters were used to develop a soil microbial activity index (SMAI), and eight soil health indicators were correlated with changes in SMAI and crop productivity. Results: The SMAI peaked under good-quality water (GQW) conditions (0.84–0.89), while the lowest values were recorded under ALKW2 (0.06–0.18). Neutralized alkali waters, ALKW₂ + SA and ALKW₂ + GYP, significantly improved SMAI with corresponding values of 0.25–0.35 and 0.13–0.32, respectively. SMAI across all stages correlated positively (R² = 0.91–0.98) with rice yield. Microbial activity varied with the crop growth stage, peaking at tillering. Gypsum application alone, aimed at neutralizing alkalinity from an RSC of 10 to 5 me L⁻¹, proved insufficient in bringing the SMAI up to the ALKW1 (RSC level of 5 me L⁻¹). Conclusions: The application of dilute sulfuric acid demonstrated better results in restoring the soil microbial activity index than gypsum amendment; however, sulfuric acid treatment depends on native calcium carbonate (CaCO₃) dissolution for its effectiveness. It may not suffice for soil stability improvement in the long term, especially when native CaCO₃ is low. Therefore, integrating gypsum and dilute sulfuric acid for RSC neutralization is worthwhile; however, further assessment is needed to confirm their combined impact on soil biochemical and physical properties.