Saline water irrigation offers a potential solution for sustaining crop yields under freshwater scarcity. However, it carries risks such as soil structure deterioration and soil organic matter decomposition, which could accelerate nutrient release. Elevated soil salinity further hampers crop growth and reduces nutrient uptake, particularly affecting phosphorus absorption. This study investigated the dynamics of soil pH, electrical conductivity, water content and available phosphorus throughout the entire growth period of oat treated with 1, 3, and 5 g L−1 saline water. It also examined the post-harvest responses of soil aggregates and their associated phosphorus, as well as the above-ground biomass and phosphorus content in various oat organs. The results showed that 1) Compared to the 1 g L−1, 3 and 5 g L−1 treatments significantly increased soil electrical conductivity and water content throughout most of the growth period, with the 5 g L−1 treatment also significantly increasing soil available phosphorus content; 2) The 3 and 5 g L−1 treatments significantly reduced the soil macro-aggregate (>1 mm) proportion by 24.76 % and 36.36 % (p < 0.05), while increasing soil micro-aggregate (<0.053 mm) by 39.41 % and 71.59 % (p < 0.05), along with higher available phosphorus content in the < 0.053 mm fraction; 3) The above-ground phosphorus content in oats decreased by 30.27 % and 35.39 % under the 3 and 5 g L−1 treatments, respectively, compared to the 1 g L−1 treatment. Partial least squares structural equation modeling revealed the different reduction pathways: 3 g L−1 saline water inhibited crop phosphorus absorption by reducing phosphorus concentrations in stem and shell (Path coefficient [PC] = 0.796, p < 0.001), whereas 5 g L−1 reduced it by decreasing the stem and seed biomass (Path coefficient [PC] = 0.816, p < 0.001). This study reveals the effects of saline water irrigation on soil and crop phosphorus availability, providing valuable insights for optimizing saline water use and enhancing phosphorus availability in agricultural systems.

中文翻译：

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盐水浓度决定了燕麦磷吸收的还原途径


盐水灌溉为在淡水短缺的情况下维持作物产量提供了一种潜在的解决方案。然而，它存在土壤结构恶化和土壤有机质分解等风险，这可能会加速养分的释放。土壤盐分升高进一步阻碍了作物生长，减少了养分吸收，特别是影响磷的吸收。本研究调查了 1、3 和 5 g L-1 盐水处理燕麦整个生育期土壤 pH 值、电导率、含水量和有效磷的动态变化。它还检查了土壤团聚体及其相关磷的收获后响应，以及各种燕麦器官中的地上生物量和磷含量。结果表明：1） 与 1 g L-1 相比，3 和 5 g L-1 处理在大部分生育期显著增加了土壤电导率和含水量，5 g L-1 处理也显著增加了土壤速效磷含量;2） 3 和 5 g L−1 处理显著降低土壤大团聚体 （>1 mm） 比例 24.76 % 和 36.36 % （p < 0.05），同时土壤微团聚体 （<0.053 mm） 增加 39.41 % 和 71.59 % （p < 0.05），同时 < 0.053 mm 分数中的有效磷含量更高;3） 与 1 g L−1 处理相比，3 g L−1 处理下燕麦地上磷含量分别降低了 30.27 % 和 35.39 %。偏最小二乘结构方程模型揭示了不同的还原途径：3 g L-1 盐水通过降低茎和壳中的磷浓度来抑制作物磷的吸收（路径系数 [PC] = 0.796，p < 0.001），而 5 g L-1 通过降低茎和种子生物量来降低它（路径系数 [PC] = 0.816，p < 0.001）。本研究揭示了盐水灌溉对土壤和作物磷有效性的影响，为优化盐水利用和提高农业系统中的磷可用性提供了有价值的见解。