Tang Chong, Yang Jingsong, Yang Chihao, Li Tao, Liu Yuxing, Gao Qiancheng, Xie Wenping, Yao Rongjiang, Wang Xiangping
State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, 211135, China; University of Chinese Academy of Sciences, Beijing, 100049, China.
State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, 211135, China; College of Resources and Environment, Xinjiang Agricultural University, Urumqi, 830052, China.
J Environ Manage. 2025 Jul 7;391:126459. doi: 10.1016/j.jenvman.2025.126459.
Reducing irrigation water utilization and improving water use efficiency (WUE) are critical for sustainable agriculture in arid areas with saline soils. However, reduced irrigation exacerbates salt stress in saline soils, presenting a paradoxical challenge for increasing WUE. To address this issue, three straw-based composite amendments, including a liquid film combined with a straw layer (LFSG), biochar combined with straw (SBSH), and polyacrylamide combined with straw (PAMSH), were selected to evaluate their effects on saline soil properties and WUE under normal irrigation (NI, 75 % water holding capacity) and deficit irrigation (DI, 55 % water holding capacity) through a pot experiment. The results demonstrated that the LFSG treatment significantly increased WUE regardless of NI or DI, primarily through dual regulation of soil water and salinity redistribution, with minimal association with nutrient availability or enzymatic activities. The spatial‒temporal analysis revealed divergent patterns in the upper straw layer of the LFSG treatment: NI decreased salinity by 25 %, whereas DI elevated both the soil water content and salinity, suggesting buried layer-driven water and salinity mobilization. The SBSH treatment resulted in irrigation-dependent outcomes. Under NI, the SBSH treatment achieved the highest WUE by increasing salinity leaching and improving the soil nutrient transformation efficiency (increasing the activities of C-, N-, and P-related enzymes). Conversely, the SBSH treatment triggered synergistic water and salinity stress under DI, thereby reducing the WUE. The PAMSH treatment significantly increased soil water retention and reduced crop water consumption but paradoxically suppressed WUE, likely due to low water effectiveness and salinity leakage. This adverse effect of PAMSH on WUE under DI was partially mitigated through extended growth cycles. These results show that the effect of amendments on WUE is irrigation-dependent and is governed by competing water-salinity-nutrient interactions. This study emphasizes the importance of integrating amendment selection with hydrological conditions to achieve synergistic water-salinity management and WUE improvement in arid saline soil agroecosystems.
在盐碱地干旱地区，减少灌溉用水并提高水分利用效率（WUE）对可持续农业至关重要。然而，减少灌溉会加剧盐碱地的盐胁迫，这给提高WUE带来了矛盾的挑战。为解决这一问题，通过盆栽试验选择了三种基于秸秆的复合改良剂，包括液膜与秸秆层组合（LFSG）、生物炭与秸秆组合（SBSH）以及聚丙烯酰胺与秸秆组合（PAMSH），来评估它们在正常灌溉（NI，田间持水量的75%）和亏缺灌溉（DI，田间持水量的55%）条件下对盐碱土性质和WUE的影响。结果表明，无论NI或DI条件下，LFSG处理均显著提高了WUE，主要是通过对土壤水分和盐分再分布的双重调节，与养分有效性或酶活性关联最小。时空分析揭示了LFSG处理秸秆上层的不同模式：NI使盐分降低了25%，而DI提高了土壤含水量和盐分，表明埋藏层驱动了水分和盐分的移动。SBSH处理的结果依赖于灌溉。在NI条件下，SBSH处理通过增加盐分淋洗和提高土壤养分转化效率（提高与碳、氮和磷相关酶的活性）实现了最高的WUE。相反，在DI条件下，SBSH处理引发了水分和盐分胁迫的协同作用，从而降低了WUE。PAMSH处理显著提高了土壤保水性并减少了作物耗水量，但矛盾的是抑制了WUE，可能是由于水分有效性低和盐分渗漏。通过延长生长周期，部分缓解了PAMSH在DI条件下对WUE的这种不利影响。这些结果表明，改良剂对WUE的影响依赖于灌溉，并且受水分-盐分-养分相互竞争的相互作用支配。本研究强调了将改良剂选择与水文条件相结合以实现干旱盐碱土农业生态系统中水分-盐分协同管理和WUE提高的重要性。
