Università degli Studi di Bari Aldo Moro, Bari, Italy; Centro de Edafología y Biología Aplicada del Segura (CEBAS-CSIC), Murcia, Spain.
Centro de Edafología y Biología Aplicada del Segura (CEBAS-CSIC), Murcia, Spain.
Sci Total Environ. 2021 Jul 15;778:146148. doi: 10.1016/j.scitotenv.2021.146148. Epub 2021 Mar 2.
Climate change is one of the main challenges facing the agricultural sector as it strives to meet global food needs. In arid and semiarid areas, the scarcity of water imposes the use of alternative sources - such as reclaimed water (RW) or desalinated water (DW) - and of deficit irrigation strategies, such as regulated deficit irrigation (RDI), in order to maintain productivity. The impact of both alternative water sources and RDI strategies on soil microbial communities in conjunction with the crop response has been little studied, and far less in fruit trees. Here, we evaluated the effects of the irrigation water quantity (RDI or the optimal water amount) and quality (DW or saline RW) on: i) the biomass, composition, and activity of the soil microbial community, and ii) the plant agro-physiological response at the level of the water status, nutrients, vegetative growth, and yield of almond trees. The DW-RDI treatment had a lower vegetative growth than the rest, reducing the nutrient requirements and increasing the contents of organic carbon and nitrogen in soil. This coincided with a significant increase in the bacterial biomass and enzyme activities in soil, as well as with a decrease in plant nutrient use efficiencies and yield. Irrigation with RW increased the fungal biomass. When there were no water restrictions (RW-FI), none of the plant agro-physiological parameters were affected; when RDI was applied (RW-RDI), the highest soil sodicity was reached and vegetative growth and yield were negatively affected, although the plant nutrient use efficiencies did not decrease as much as with DW-RDI. In addition, the plant nutrient use efficiencies were negatively correlated with the soil enzyme activities. These results improve our knowledge of the functioning of plant-soil interactions in Mediterranean crops subjected to different irrigation strategies.
气候变化是农业部门面临的主要挑战之一，因为它努力满足全球粮食需求。在干旱和半干旱地区，水资源的稀缺性迫使人们使用替代水源，如再生水（RW）或淡化水（DW），并采用亏缺灌溉策略，如调控亏缺灌溉（RDI），以维持生产力。替代水源和 RDI 策略对土壤微生物群落的影响以及对作物的响应，研究得还很少，在果树上的研究就更少了。在这里，我们评估了灌溉水量（RDI 或最佳水量）和质量（DW 或咸 RW）对以下方面的影响：i）土壤微生物群落的生物量、组成和活性，以及 ii）杏仁树的植物农业生理响应，包括水分状况、养分、营养生长和产量。DW-RDI 处理的营养生长低于其他处理，降低了养分需求，增加了土壤中有机碳和氮的含量。这与土壤中细菌生物量和酶活性的显著增加以及植物养分利用效率和产量的降低相吻合。RW 灌溉增加了真菌生物量。当没有水分限制时（RW-FI），植物的农业生理参数都不受影响；当应用 RDI 时（RW-RDI），土壤的最高碱度达到，营养生长和产量受到负面影响，尽管植物养分利用效率的下降幅度不如 DW-RDI 那么大。此外，植物养分利用效率与土壤酶活性呈负相关。这些结果提高了我们对不同灌溉策略下地中海作物中植物-土壤相互作用功能的认识。
