University of Tehran Press Iranian Journal of Soil and Water Research 2008-479X 56 6 2025 08 23 The effect of conservation tillage on soil biological and enzymatic activities and physiological characteristics of corn (Zea mays L.) under drought stress conditions The effect of conservation tillage on soil biological and enzymatic activities and physiological characteristics of corn (Zea mays L.) under drought stress conditions 1571 1592 103839 10.22059/ijswr.2025.394078.669931 FA Nezam Karzani Department of Agriculture, Faculty of Agriculture, University of Ilam, Iran Ehsan Allah Zaid Ali Department of Agriculture, Faculty of Agriculture, University of Ilam, Iran Yaser Alizadeh Department of Agriculture, Faculty of Agriculture, University of Ilam, Iran Hamzeh Ali Alizadeh Department of Water, Faculty of Agriculture, University of Ilam. Iran Ekhlas Amini Ilam Agricultural Jihad Organization. Iran Journal Article 2025 04 28 To investigate the effect of conservation tillage on soil biological and enzymatic activities and physiological characteristics of maize under drought stress conditions, an experiment was conducted based on a split-plot design in a randomized complete block design with three replications and 15 treatments in 2023 at the Ilam University Research Farm. The main therapies included three tillage levels (no-tillage, minimum tillage, and conventional tillage), and the sub-treatments included five irrigation regimes (100, 75, and 50 percent of field capacity with full irrigation and 75 and 50 percent with PRD local root drought method). The results showed that the highest relative leaf water content (85.62%) was observed in the 100 percent field capacity irrigation treatment. The highest proline accumulation (2.06 μmol/g leaf fresh weight) was observed in the 50 percent irrigation level. Catalase activity reached its maximum value (1.93 absorption change/min/mg protein) in the no-tillage treatment with 50 percent PRD irrigation. Malondialdehyde and ascorbate peroxidase also showed the highest levels at the 50% irrigation. In the section on soil enzymatic activities, alkaline phosphatase was recorded at 430.11 and 417.74 μg/g soil in the tillage treatments with 100 and 75% PRD irrigation, respectively. Acid phosphatase, urease, and microbial respiration also had the highest levels in the tillage treatment with full irrigation. The findings indicate that the combination of tillage system with the PRD technique can be used as an effective solution for drought stress management. These methods enhance plant defense responses and provide more favorable biological conditions for soil. To investigate the effect of conservation tillage on soil biological and enzymatic activities and physiological characteristics of maize under drought stress conditions, an experiment was conducted based on a split-plot design in a randomized complete block design with three replications and 15 treatments in 2023 at the Ilam University Research Farm. The main therapies included three tillage levels (no-tillage, minimum tillage, and conventional tillage), and the sub-treatments included five irrigation regimes (100, 75, and 50 percent of field capacity with full irrigation and 75 and 50 percent with PRD local root drought method). The results showed that the highest relative leaf water content (85.62%) was observed in the 100 percent field capacity irrigation treatment. The highest proline accumulation (2.06 μmol/g leaf fresh weight) was observed in the 50 percent irrigation level. Catalase activity reached its maximum value (1.93 absorption change/min/mg protein) in the no-tillage treatment with 50 percent PRD irrigation. Malondialdehyde and ascorbate peroxidase also showed the highest levels at the 50% irrigation. In the section on soil enzymatic activities, alkaline phosphatase was recorded at 430.11 and 417.74 μg/g soil in the tillage treatments with 100 and 75% PRD irrigation, respectively. Acid phosphatase, urease, and microbial respiration also had the highest levels in the tillage treatment with full irrigation. The findings indicate that the combination of tillage system with the PRD technique can be used as an effective solution for drought stress management. These methods enhance plant defense responses and provide more favorable biological conditions for soil. https://ijswr.ut.ac.ir/article_103839_118109c1fa227b7c7d17348bc8e18a2e.pdf