University of Isfahan Journal of Plant Biological Sciences 3041-9603 15 1 2023 05 22 Influence of Soil Application of Natural Zeolite and Farmyard Manure on Physiological Indices of Grapevine under Drought Stress Influence of Soil Application of Natural Zeolite and Farmyard Manure on Physiological Indices of Grapevine under Drought Stress 65 84 28174 10.22108/ijpb.2024.139739.1340 FA Mohamadreza Zokaee Khosroshahi Department of Horticultural and Landscape Engineering, Faculty of Agriculture, Malayer University, Malayer, Iran Rouhollah Karimi Department of Horticultural and Landscape Engineering, Faculty of Agriculture, Malayer University, Malayer, Iran Amin Toranjian Department of Soil and Water Sciences, Faculty of Agriculture, Malayer University, Malayer, Iran Journal Article 2023 11 10 Soil application of farmyard manures and moisture-absorbing materials such as natural zeolite is considered a simple and cheap way to conserve soil moisture in arid areas and light soils. To study the effect of two soil amendments on the physiological properties of “Bidaneh Sefid” grapevines under drought stress, an experiment was conducted in factorial based on a randomized block design in the research vineyard of Malayer University, Hamadan, Iran during the 2022 and 2023 growing seasons. The treatments included two levels of irrigation cycle (7 and 21 d intervals) and four levels of soil amendments (control, 12 kg zeolite vine^-1, 15 kg sheep manure vine^-1, a combination of 12 kg zeolite + 15 kg sheep manure vine^-1). Results showed that the drought stress led to a decrease in chlorophyll content, leaf relative water content, and leaf water potential. Drought stress also led to an increase in electrolyte leakage and the activity of antioxidant enzymes. Application of farmyard manure and zeolite moderated all the investigated indicators, due to their ability to absorb and retain water in the soil. The results of the study showed that it is possible to mitigate the adverse effects of drought stress on grapevine by retaining the moisture of light soils by the application of natural zeolite, alone or in combination with farmyard manure. <strong> </strong> <strong>Introduction</strong> Food production has decreased in more than 20% of the world's agricultural lands due to drought. One of the ways to deal with water scarcity in arid and semi-arid areas is to maintain soil moisture and improve soil water retention. Soil application of farmyard manures and moisture-absorbing materials such as natural zeolite is considered a simple and cheap way to conserve soil moisture in arid areas and light soils.   <strong>Material and Methods</strong> To study the effect of two soil amendments on the physiological properties of “Bidaneh Sefid” grapevines under drought stress, an experiment was conducted in factorial based on a randomized block design in the research vineyard of Malayer University, Hamadan, Iran during the 2022 and 2023 growing seasons. The treatments included two levels of irrigation cycle (7 and 21 d intervals) and four levels of soil amendments (control, 12 kg zeolite vine^-1, 15 kg sheep manure vine^-1, a combination of 12 kg zeolite + 15 kg sheep manure vine^-1). Soil amendments were applied in late winter. Leaf samples (fully expanded healthy leaves at the node of 8–10th from the base of canes of each vine) were collected in late-July, one day before irrigation, and were transferred quickly to the laboratory for measurements. All data were subjected to analysis of variance (ANOVA) using the general linear models (GLM) procedure in SAS software and the means were compared using Duncan’s multiple range test.   <strong>Results and Discussion</strong> Results showed that the drought stress led to a decrease in chlorophyll content (by 21.4%), leaf relative water content (by 21.4%), and leaf water potential (by 12%). Drought stress also led to an increase in electrolyte leakage (by 39.4%) and the activity of antioxidant enzymes. Effect of drought stress on activity of all antioxidant enzymes except guaiacol peroxidase (POD) was significant. Activities of catalase (CAT), superoxide dismutase (SOD), ascorbate peroxidase (APX), and glutathione reductase (GR) enzymes increased by 140.3, 210.6, 153.2 and 26.2%, respectively, as irrigation interval increased from 7 to 21 days. Application of zeolite, sheep manure, and their combination increased leaf chlorophyll content by 16.9, 21.7 and 32.9%, respectively. Under drought conditions the application of soil amendment had a significant effect, so that the leaf RWC of vines treated with zeolite, sheep manure and their combination was 16.1, 22.2 and 20.6% higher than untreated vines, respectively. Soil application of amendments reduced the negative effect of drought stress on leaf water potential, so that the Ψ_Leaf of vines treated with zeolite, sheep manure, and both zeolite and manure were 10.9%, 5.4% and 25.2% higher than untreated vines, respectively. The use of soil amendments significantly reduced EL caused by drought stress, so that the vines treated with sheep manure, zeolite and their combination had a less electrolyte leakage by 14.1, 17.8 and 25.6%, respectively compared to control. Soil application of zeolite and sheep manure had a significant effect on the activity of leaf antioxidant enzymes. In well-watered vines, use of soil amendments led to a significant decrease of CAT, SOD and APX activity, so that the difference between applied treatments and control was significant. POD activity in well-watered vines that received both soil amendments was significantly lower than the control. Also, application of sheep manure led to a significant decrease of GR activity in non-stressed conditions. In drought stress conditions, except for POD, which was not affected by treatments, activity of other enzymes decreased significantly in response to soil application of zeolite, sheep manure and their combination compared to the control. Overall, the results of the present study indicate reduction of antioxidant enzymes activity and H₂O₂ content in grape leaves following soil application of zeolite and sheep manure. These results may be related to an increased soil water retention capacity and thereby, a reduced water deficit because of adding zeolite and sheep manure to the soil.     <strong>Conclusion</strong> The results of the present study suggest that the adverse effects of drought stress on grapevines grown in light-textured poor soils can be diminished by using natural zeolite and farmyard manure as soil ameliorants. Natural zeolites, which have unique characteristics, are found abundantly in many parts of the world including Iran and have a low price. In addition, unlike sheep manure, zeolite does not increase soil salinity. Therefore, the use of natural zeolites combined with animal manures and other organic fertilizers can be one of the possible strategies to cope with drought-related problems in arid and semi-arid regions of the world.           Soil application of farmyard manures and moisture-absorbing materials such as natural zeolite is considered a simple and cheap way to conserve soil moisture in arid areas and light soils. To study the effect of two soil amendments on the physiological properties of “Bidaneh Sefid” grapevines under drought stress, an experiment was conducted in factorial based on a randomized block design in the research vineyard of Malayer University, Hamadan, Iran during the 2022 and 2023 growing seasons. The treatments included two levels of irrigation cycle (7 and 21 d intervals) and four levels of soil amendments (control, 12 kg zeolite vine^-1, 15 kg sheep manure vine^-1, a combination of 12 kg zeolite + 15 kg sheep manure vine^-1). Results showed that the drought stress led to a decrease in chlorophyll content, leaf relative water content, and leaf water potential. Drought stress also led to an increase in electrolyte leakage and the activity of antioxidant enzymes. Application of farmyard manure and zeolite moderated all the investigated indicators, due to their ability to absorb and retain water in the soil. The results of the study showed that it is possible to mitigate the adverse effects of drought stress on grapevine by retaining the moisture of light soils by the application of natural zeolite, alone or in combination with farmyard manure. <strong> </strong> <strong>Introduction</strong> Food production has decreased in more than 20% of the world's agricultural lands due to drought. One of the ways to deal with water scarcity in arid and semi-arid areas is to maintain soil moisture and improve soil water retention. Soil application of farmyard manures and moisture-absorbing materials such as natural zeolite is considered a simple and cheap way to conserve soil moisture in arid areas and light soils.   <strong>Material and Methods</strong> To study the effect of two soil amendments on the physiological properties of “Bidaneh Sefid” grapevines under drought stress, an experiment was conducted in factorial based on a randomized block design in the research vineyard of Malayer University, Hamadan, Iran during the 2022 and 2023 growing seasons. The treatments included two levels of irrigation cycle (7 and 21 d intervals) and four levels of soil amendments (control, 12 kg zeolite vine^-1, 15 kg sheep manure vine^-1, a combination of 12 kg zeolite + 15 kg sheep manure vine^-1). Soil amendments were applied in late winter. Leaf samples (fully expanded healthy leaves at the node of 8–10th from the base of canes of each vine) were collected in late-July, one day before irrigation, and were transferred quickly to the laboratory for measurements. All data were subjected to analysis of variance (ANOVA) using the general linear models (GLM) procedure in SAS software and the means were compared using Duncan’s multiple range test.   <strong>Results and Discussion</strong> Results showed that the drought stress led to a decrease in chlorophyll content (by 21.4%), leaf relative water content (by 21.4%), and leaf water potential (by 12%). Drought stress also led to an increase in electrolyte leakage (by 39.4%) and the activity of antioxidant enzymes. Effect of drought stress on activity of all antioxidant enzymes except guaiacol peroxidase (POD) was significant. Activities of catalase (CAT), superoxide dismutase (SOD), ascorbate peroxidase (APX), and glutathione reductase (GR) enzymes increased by 140.3, 210.6, 153.2 and 26.2%, respectively, as irrigation interval increased from 7 to 21 days. Application of zeolite, sheep manure, and their combination increased leaf chlorophyll content by 16.9, 21.7 and 32.9%, respectively. Under drought conditions the application of soil amendment had a significant effect, so that the leaf RWC of vines treated with zeolite, sheep manure and their combination was 16.1, 22.2 and 20.6% higher than untreated vines, respectively. Soil application of amendments reduced the negative effect of drought stress on leaf water potential, so that the Ψ_Leaf of vines treated with zeolite, sheep manure, and both zeolite and manure were 10.9%, 5.4% and 25.2% higher than untreated vines, respectively. The use of soil amendments significantly reduced EL caused by drought stress, so that the vines treated with sheep manure, zeolite and their combination had a less electrolyte leakage by 14.1, 17.8 and 25.6%, respectively compared to control. Soil application of zeolite and sheep manure had a significant effect on the activity of leaf antioxidant enzymes. In well-watered vines, use of soil amendments led to a significant decrease of CAT, SOD and APX activity, so that the difference between applied treatments and control was significant. POD activity in well-watered vines that received both soil amendments was significantly lower than the control. Also, application of sheep manure led to a significant decrease of GR activity in non-stressed conditions. In drought stress conditions, except for POD, which was not affected by treatments, activity of other enzymes decreased significantly in response to soil application of zeolite, sheep manure and their combination compared to the control. Overall, the results of the present study indicate reduction of antioxidant enzymes activity and H₂O₂ content in grape leaves following soil application of zeolite and sheep manure. These results may be related to an increased soil water retention capacity and thereby, a reduced water deficit because of adding zeolite and sheep manure to the soil.     <strong>Conclusion</strong> The results of the present study suggest that the adverse effects of drought stress on grapevines grown in light-textured poor soils can be diminished by using natural zeolite and farmyard manure as soil ameliorants. Natural zeolites, which have unique characteristics, are found abundantly in many parts of the world including Iran and have a low price. In addition, unlike sheep manure, zeolite does not increase soil salinity. Therefore, the use of natural zeolites combined with animal manures and other organic fertilizers can be one of the possible strategies to cope with drought-related problems in arid and semi-arid regions of the world.           https://ijpb.ui.ac.ir/article_28174_2e604a1a9fef64bd4510c55a61502e71.pdf