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One of the most significant challenges in arid and semi-arid regions is the presence of abiotic environmental stresses, particularly drought stress, which affects the growth and development of plants. Elaeagnus angustifolia, as a species resistant to drought stress, is utilized for revegetation of barren areas, soil conservation, and creation of green spaces. An experiment was conducted in Semnan city to assess the impact of varying levels of drought stress on one-year-old elm seedlings using a completely randomized design. The experiment included four stress levels: control (100% available water), mild stress (75% available water), moderate stress (50% available water), and severe stress (25% available water). The results indicated that there was no significant difference between drought stress levels regarding the height and diameter of seedlings, while significant differences were observed in leaf number, vitality, root dry weight, and stem dry weight. The control group and mild stress conditions exhibited the highest number of leaves (25), freshness (>95%), root dry weight (>5 grams), and stem dry weight (>8 grams). As drought stress levels increased, there was a noticeable decrease in the number of leaves, survival rate, freshness, root dry weight, and stem dry weight. Regarding the vitality of seedlings, it was found that vitality remained at 100% in all drought stress levels except for severe stress, where vitality gradually decreased to zero after 7 months. Generally, the results demonstrated that the best outcome, which included acceptable growth and optimal water consumption, was attainable under mild stress conditions (75% available water). Indeed, this species demonstrated the ability to endure moderate drought stress conditions (50% available water) with a 100% survival rate. Additionally, there was no significant difference in terms of the stem dry weight (7.5 grams) compared to the control sample. This indicates that the elm species is resilient to water stress and can be effectively utilized for planting in green spaces within dry climate regions. [ABSTRACT FROM AUTHOR]

Acer velutinum Boiss. (Persian or velvet maple) is one of the industrial and important species of Hyrcanian (Caspian) forests with wide distribution. This species is rarely seen in the forests of other parts of the world and has only been reported from the forests of the Caucasus. Therefore the information about this species is very limited. This research aims to investigate the response of A. velutinum seedlings to drought stress as one of the consequences of climate change. Seedlings of velvet maple were analyzed in terms of height, basal diameter, leaf area (LA), specific leaf area (SLA), biomass, photosynthesis pigments, relative water content RWC), free proline, malondialdehyde (MDA), superoxide dismutase(SOD), and peroxidase(POD) activities to drought stress. One year old of Potted plants were exposed to four water supply regimes (100, 75, 50, and 25% field capacity (FC); performed as a control, mild, moderate, and severe water stress. The results showed that drought reduced all aspects of growth in the velvet maple. It negatively affected on growth and reduced plant height, stem diameter, biomass, and leaf area, but SLA significantly increased under moderate treatment. Drought stress reduced chlorophyll content, however, no significant difference was found for carotenoids. RWC reduced significantly just under severe drought stress. Proline and MDA content increased significantly when plants were exposed to moderate and severe drought stress. Drought stress induced POD and SOD activity under drought treatments, although the highest activities were measured under mild and moderate treatments. Our data demonstrate that A. velutinum seedlings have relative drought resistance. They used drought avoidance and tolerance mechanisms through changes in morpho-physiological characteristics. The results of this research briefly showed the mechanisms of drought tolerance in A. velutinum and will provide essential information for more research in the future. [ABSTRACT FROM AUTHOR]

Today, by increasing industrial and agricultural activities and the subsequent increase in pollutants, soil and water pollution has become a serious environmental problem. The increase of pollutants in the soil in the conditions of dry climate and drought stress have adverse effects on the biological indicators. In this study the combined effect of cadmium at six levels (0, 5, 10, 20, 40 and 80 mg kg-1 soil) in the form of cadmium sulfate (CdSO4) and three irrigation intervals (2, 4 and 7 days) as a factorial experiment in the form of a completely random basic design with three replications was investigated on spinach (Spinosa oleracea) and lettuce (Lactuca sativa) in calcareous soil with silty clay texture. The obtained results showed that increasing the concentration of cadmium in the soil caused a significant decrease in the average dry weight of leaves and stems of lettuce and spinach. The average dry weight reduction percentage compared to the control at the highest level of cadmium was observed in lettuce leaves and stems as 63 and 46% and in spinach leaves and stems as 54 and 38%, respectively. Increasing the irrigation intervals decreased the dry weight of lettuce and spinach plants significantly compared to the control. The percentage of mean dry weight reduction in 4 and 7 days irrigation intervals compared to 2 days irrigation interval in lettuce leaf and stem was 23, 41, 31 and 63% and in spinach was 19, 39, 24 and 49%, respectively. The increase in cadmium levels increased the concentration of this element in the stem and leaves of lettuce and spinach plants, and by increasing irrigation intervals, the concentration and uptake of cadmium in the leaves and stems of spinach and lettuce decreased. The results of this research showed that the spinach plant absorb and transport cadmium metal more than the lettuce. The stress sensitivity index showed that the moisture stress has reduced the crop tolerance to cadmium. Based on the decrease in dry weight at different levels of cadmium, it can be said that the stem of two plants is more tolerant to cadmium than the leaf. [ABSTRACT FROM AUTHOR]

This study investigates the effects of different tillage systems (no-tillage, minimum and conventional), fertilizers (no fertilizer, vermicompost (V), urea (U) and combined urea and vermicompost (VU) and irrigation regimes on various quantitative and qualitative traits of rapeseed, as well as soil nitrate leaching (NL). Field trials" have been conducted between 2017 and 2019 in the Research Institute of Forests and Rangelands with no significant difference observed for seed and oil yield between the minimum and conventional till systems. However, the nuore-ati lul nsdyeter *omp tvims aml iirnriigmautimon a cnodn cdoitniovnesn tbioonoaslt st ioli ld yeicerldea bsye t2h4e%se, tcraoimtsp aarre d2 2to% * thaen dc o2n1t.r5o%l). oTf hraep ceosemebdi.n Fedu rathpeprlmicoarteio, na corfo>svse armll i't؟iollmagpe٥ tsytpaensd, the highest NL is observed where urea was applied. When compared with urea, V and UV treatments decrease the NL by 67% and 50% in no-till plots, 50% and 36% in minimum till plots, and 49% and 34% in conventional till plots, respectively. Deficit irrigation also reduces linoleic acid by 7.6%. In addition, the highest levels of oleic acid (63.9%) and linoleic acid (20.7%) are observed under residual tillage system with combined fertilizer application and the residual tillage system with vermicompost application, respectively The findings indicate that minimum till in combination with VU treatments supports reduced NL over conventional till and urea fertilization practices, while improving rapeseed quantitative and qualitative traits. [ABSTRACT FROM AUTHOR]