Salinity–induced land degradation poses a threat to environment and food production globally. Farmers' participatory research (2014–18) was carried out to assess the potential of gypsum (Gyp) and pressmud (PM) in alleviating the sodicity stress, and improvement in soil organic carbon (SOC) pools and its stability in the Trans Indo–Gangetic Plains of India. Intensive rice–wheat cultivation using alkali water increased soil pH, exchangeable sodium percentage (ESP), and bulk density (BD) causing a net depletion in SOC. Gypsum (supplies soluble Ca²⁺) and pressmud (mobilizes native CaCO₃) mediated amelioration (Gyp + PM) significantly decreased soil sodification and compaction, and improved total organic carbon (TOC; 32%–64%) over the unamended control. Higher left–over C for SOC stabilization, crop biomass, and rhizodeposition returned through Gyp + PM significantly improved SOC pools and C sequestration culminating in ~25% yield superiority over the unamended control. Within SOC pools, highest proportion was equally retained in very labile and non–labile C pools. On average, the passive pool contained ~45% of TOC; albeit to a greater contribution through PM followed by Gyp + PM and Gyp. Rice–wheat system yield (RWSY) was positively correlated with SOC pools and indices while negatively correlated with soil pH, ESP, BD, CaCO_3, and recalcitrant index. Multiple regression analysis showed stratification ratio, CaCO₃, sensitivity index, and BD as key variables for yield prediction under the existing levels of soil sodicity. The key insights suggest ecosystem-based approach using Gyp + PM in restoring the degraded lands, enhancing crop resilience and system (SOC enrichment and storage) stability, and achieving UN–Sustainable Development Goals related to food security and land degradation neutrality.

中文翻译：

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石膏和压泥改良改善土壤有机碳储存和钠盐农业生态系统的稳定性

盐分引起的土地退化对全球环境和粮食生产构成威胁。开展了农民参与研究（2014-18 年）以评估石膏 (Gyp) 和压泥 (PM) 在减轻碱度压力、改善土壤有机碳 (SOC) 库及其稳定性方面的潜力。印度恒河平原。使用碱水集约化稻麦种植会增加土壤 pH 值、可交换钠百分比 (ESP) 和容重 (BD)，导致 SOC 的净消耗。石膏（提供可溶性 Ca ²⁺）和压泥（动员天然 CaCO ₃) 介导的改善 (Gyp + PM) 显着降低了土壤的钠化和压实，并改善了总有机碳 (TOC；32%–64%) 与未修改的对照相比。通过 Gyp + PM 返回的用于 SOC 稳定、作物生物量和根际沉积的较高剩余 C 显着改善了 SOC 池和 C 封存，最终与未修改的对照相比，产量优势达到约 25%。在 SOC 池中，最高比例同样保留在非常不稳定和非不稳定 C 池中。平均而言，被动池包含约 45% 的 TOC；尽管通过 PM 的贡献更大，其次是 Gyp + PM 和 Gyp。水稻-小麦系统产量 (RWSY) 与 SOC 库和指数呈正相关，而与土壤 pH、ESP、BD、CaCO ₃呈负相关_，和顽固的指数。多元回归分析显示分层比、CaCO ₃、敏感性指数和BD作为在现有土壤碱度水平下产量预测的关键变量。关键见解建议使用 Gyp + PM 的基于生态系统的方法来恢复退化的土地，增强作物恢复力和系统（SOC 富集和储存）稳定性，并实现与粮食安全和土地退化中性相关的联合国可持续发展目标。