Abstract Unconventional water resources such as treated wastewater (TWW) are being increasingly used for irrigation in regions with limited freshwater availability. Likewise, subsurface drip irrigation (SSDI) has been proposed for improving water use efficiency in arid lands. The combined effects of both factors (SSDI/TWW) on soil health have received little attention. This study assessed the mid-term (6 years) impact of irrigation with TWW apply by SSDI and surface drip irrigation (SDI) on soil chemical properties and enzyme activities under arid climate. The calculation of a numerical index (integrated biological response version 2; IBRv2) for enzymatic activities showed a significant deviation in soils irrigated with TWW with regard to control soils (irrigated with desalinated brackish water–DBW), particularly after SSDI. That combination TWW/SSDI inhibited most of assessed enzyme activities, save for catalase, with respect to the reference treatment (for example in a clay-loamy soil, decrease varied between 69% for esterase and 12% for dehydrogenase). Increased soil salinity (up to EC~15 dS m−1) due to SSDI/TWW appears as one of the potential factors involved. These results suggest that current irrigation strategies in arid lands might accelerate soil degradation processes in regions where desertification is of particular concern.

中文翻译：

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灌溉管理对干旱土壤酶活性的影响

摘要 处理过的废水 (TWW) 等非常规水资源正越来越多地用于淡水供应有限的地区的灌溉。同样，地下滴灌 (SSDI) 已被提议用于提高干旱地区的水资源利用效率。这两个因素（SSDI/TWW）对土壤健康的综合影响很少受到关注。本研究评估了 SSDI 和地表滴灌 (SDI) 应用 TWW 灌溉对干旱气候下土壤化学性质和酶活性的中期（6 年）影响。酶活性的数值指数（综合生物响应版本 2；IBRv2）的计算表明，与对照土壤（用淡化咸水-DBW 灌溉）相比，用 TWW 灌溉的土壤存在显着偏差，特别是在 SSDI 之后。该组合 TWW/SSDI 抑制了大部分评估的酶活性，除了过氧化氢酶，相对于参考处理（例如在粘壤土中，酯酶降低 69%，脱氢酶降低 12%）。由于 SSDI/TWW 导致的土壤盐分增加（高达 EC~15 dS m-1）似乎是所涉及的潜在因素之一。这些结果表明，目前干旱地区的灌溉策略可能会加速荒漠化特别受到关注的地区的土壤退化过程。