فعالية الري بالمياه الجوفية الساخنة في الخصائص الفيزيولوجية والفيتوكيميائية لنبات النعناع المائي والنعناع الجبلي ونبات البوقريبة

Abstract

This study aims to evaluate the effectiveness of irrigation using hot groundwater on a range of physiological and phytochemical characteristics in three common medicinal plants: water mint (Mentha aquatica), mountain mint (Mentha longifolia), and Zygophyllum cornutum, under the harsh environmental conditions typical of arid regions such as the Wadi Souf area in southern Algeria. Two irrigation treatments (hot groundwater (50°C) and cooled hot groundwater (30°C) were applied to the studied plants. Various physiological and biochemical indicators were then measured, including chlorophyll content, water content, cellular water capacity, yield, total polyphenols, flavonoids, tannins, and antioxidant activity (using DPPH and FRAP assays). The results revealed significant differences between the treatments. Irrigation with cooled hot groundwater showed a positive effect on most of the indicators compared to direct hot groundwater irrigation, highlighting the role of thermal adjustment in improving plant response and mitigating stress impacts. Conversely, a decline in certain indicators was observed under direct hot water irrigation, indicating a potentially harmful thermal effect in the absence of cooling. Statistical analyses (ANOVA followed by the Least Significant Difference (LSD) test) confirmed statistically significant differences and revealed variability in responses among the three plant species, demonstrating differences in biochemical and physiological tolerance. The study concludes that using hot groundwater after cooling may represent a sustainable alternative for agricultural irrigation in southern Algeria, helping to maintain the quality of plant production, especially in light of current climate challenges and limited surface water resources.