The increasing utilization of non-conventional water sources, particularly in arid regions, necessitates strategies for effectively harnessing these resources. This study examines the impacts of using marginal quality waters, including recycled wastewater (RW) and brackish groundwater (BW), compared to those using desalinated brackish water (DW) as a control, on alfalfa cultivation in Fuerteventura, Canary Islands, over four years. Employing a 25 % leaching fraction in addition to organic amendments and gypsum application, the study evaluates the effects on alfalfa biomass production, mineral composition, and soil quality on two soil types (sandy-loam and clay-loam) affected by salinity. Initial and post-treatment analyses of the topsoil and soil profile revealed significant improvements in soil quality such as reductions in electrical conductivity (ECe), sodium absorption ratio and boron content, especially with RW irrigation. For instance, ECe decreased by 51 % and 26 % in the first 30 cm under irrigation with RW and BW, respectively, with regard to its initial soil conditions. Alfalfa yields under RW and BW reached 97 % and 79 % relative to those irrigated with DW in sandy-loam soil, and 92 % and 73 % in clay-loam soil, respectively. This demonstrates the capability of RW to sustain productivity levels close to those achieved with DW, highlighting its potential as a viable irrigation alternative in arid conditions. Nevertheless, irrigation with BW led to a significant reduction in alfalfa yields after the second year, which could become more pronounced over a longer period of use. Mineral analysis of alfalfa showed that irrigation water quality significantly affects the accumulation of nutrients such as iron and boron, which exceeded adequate levels for optimal livestock nutrition. The study's findings underline the importance of tailored water management strategies that optimize the use of marginal waters, ensuring sustainable agricultural practices in water-scarce environments while mitigating potential risks associated with soil salinization and nutrient imbalances.

中文翻译：

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边缘质量水域：在盐碱土壤中可持续生产牧草的充足资源？


非常规水源的利用日益增加，特别是在干旱地区，需要有效利用这些资源的战略。本研究考察了与使用淡化咸水 （DW） 作为对照的水相比，使用边际质量水（包括回收废水 （RW） 和苦咸地下水 （BW））对加那利群岛富埃特文图拉岛紫花苜蓿种植四年的影响。除了有机改良剂和石膏施用外，该研究还使用 25% 的浸出分数，评估了受盐度影响的两种土壤类型（沙壤土和粘壤土）对紫花苜蓿生物质生产、矿物成分和土壤质量的影响。对表土和土壤剖面的初始和处理后分析显示，土壤质量显著改善，例如电导率 （ECe）、钠吸收率和硼含量降低，尤其是在 RW 灌溉的情况下。例如，就其初始土壤条件而言，在用 RW 和 BW 灌溉的前 30 厘米中，ECe 分别减少了 51 % 和 26 %。相对于在沙壤土中用 DW 灌溉的苜蓿产量，RW 和 BW 下的苜蓿产量分别达到 97% 和 79%，在粘壤土中分别达到 92% 和 73%。这表明 RW 能够保持接近 DW 所达到的生产力水平，凸显了它在干旱条件下作为可行的灌溉替代方案的潜力。尽管如此，使用 BW 灌溉导致第二年后苜蓿产量显着降低，随着使用时间的延长，这种产量可能会变得更加明显。 紫花苜蓿的矿物质分析表明，灌溉水质显着影响铁和硼等营养物质的积累，这些营养物质超过了最佳牲畜营养的足够水平。该研究的结果强调了量身定制的水资源管理策略的重要性，这些策略可以优化边缘水域的利用，确保在缺水环境中实现可持续的农业实践，同时减轻与土壤盐碱化和营养失衡相关的潜在风险。