aliashraf amirinejad

The use of chelating agents has been introduced as a suitable strategy to reduce the detrimental effect of heavy metals in plants. To investigate the impacts of aspartic acid (AA) and glutamic acid (GA) in alleviating lead (Pb) stress in lemongrass (Dracocephalum ruyschiana), a factorial experiment was conducted based on a completely randomized design with three replications, in the greenhouse of Razi University, in 2023. The treatments included Pb contamination at three levels (0, 150, and 300 mg.kg-1 soil as Pb (NO3)2), aspartic acid (AA) at three levels (0, 100, and 200 mM), and glutamic acid (GA) at three levels (0, 100, and 200 mM). Both acids were used as foliar application. The results showed that the highest proline content (8.12 μmol.g-1) and soluble sugars (2.94 mg.g-1) were obtained in 300 mg.kg-1 of Pb, without AA and GA, which shows an increase of 320% and 285%, respectively, compared to the control (without Pb and chelating agents). Also, the highest amount of shoot and root dry weights, plant height, root length, and volume were found in the treatment of 200 mM of AA and GA, and without Pb. In general, AA and GA, as foliar spray could significantly reduce the adverse effects of Pb on the crop growth characteristics. Thus, application of these chelating agents is a convenient method to diminish the effect of Pb stress on lemongrass.

Lead (Pb) and cadmium (Cd) are trace elements known for potentially harming plants. Their toxicity can lead to increased oxidative harm, disturbance in plant metabolism, and deformation in plant structure. As a soil amendment, biochar (BC) effectively reduces heavy metal toxicity in polluted soils. To investigate the effects of BC derived from sunflower residues on mitigating the adverse impacts of Pb and Cd in mung bean (Vigna radiata Wilczek), a factorial experiment was conducted based on a completely randomized design with three replications in greenhouse conditions. The factors included Pb at three levels (0, 100, and 200 mg kg-1 as Pb (NO3)2), Cd at three levels (0, 10, and 20 mg kg-1 soil as Cd (NO3)2), and BC at three levels (0%, 1%, and 3% by weight). The results indicated that Pb- and Cd-induced stresses reduced all growth characteristics, such as shoot and root dry weights, and the number of active root nodules. The maximum soluble sugars (0.46 mg kg-1) and proline content (44.7 µmol g-1) were observed in the treatment with 200 mg kg-1 of Pb and 20 mg kg-1 of Cd without BC. Furthermore, applying BC decreased the concentration of Pb and Cd in the shoot by 19.1% and 13.8%, respectively, while enhancing all growth traits. Therefore, applying BC derived from sunflower residues is recommended as a promising and environmentally friendly approach to alleviating Pb- and Cd-induced stress in mung bean.

Heavy metals are non-biodegradable and persistent in nature thereby disrupting the environment and causing huge health threats to humans. Cadmium (Cd) is a toxic heavy metal that enters the environment through various anthropogenic sources, and inhibits plant growth and development. Cadmium toxicity may result from disturbance in plant metabolism as a consequence of disturbance in the uptake and translocation of mineral nutrients. The use of plant hormones has been introduced as a simple and suitable strategy to reduce the effect of heavy metals in plants. A new method for reducing the effect of cadmium on plants is the use of growth regulators such as salicylic acid (SA). Tomato (Lycopersicon esculentum) is an important vegetable that is rich in minerals, various vitamins and antioxidant compounds. Since the cultivation of tomatoe, as an important and highly productive crop, is very common in many parts of Iran, there is a possibility of contamination of the soil under cultivation with cadmium. Therefore, the present study was conducted to evaluate the the effects of foliar spraying of salicylic acid on reducing Cd-induced stress in tomato (Lycopersicon esculentum L.).

A factorial experiment based on a complete randomized design with three replications was conducted in a greenhouse of Razi University. Factors included Cd at three levels (0, 15 and 30 mg kg-1 as Cd(NO3)2) and SA at three levels (0, 250, and 500 μM). The solutions containing Cd-(NO3)2 were sprayed uniformly on the sub-samples separated from the original soil sample according to the desired concentrations. The samples were kept moist for 30 days at moisture conditions close to field capacity. At the four-leaf stage, SA solutions were sprayed three times on the foliage of the plants, until the beginning of flowering. After harvesting, some characteristics including soluble sugars and proline contents, plant height, dry weights of shoots and roots, and root volume and length were determined. All plant parameters were then averaged for each pot. Also, Cd concentrations in extracts obtained from the digestion of leaf tissues, were measured by Varian AA220 atomic absorption spectrophotometer. The analysis of variance (ANOVA) and comparison of means (Duncan's multiple range test) were performed using SPSS-16 software.

The results revealed that Cd stress reduced all plant characteristics, such as plant height, root volume and root length, as well as, dry weights of shoots and roots, and elevated leaf Cd concentration, proline content and soluble sugars in tomato. However, the SA application resulted in improvements in growth parameters. Also, the results showed that the interaction effects of Cd and SA on the most growth characteristics such as plant length, shoot and root dry weights, stem diameter, leaf area, and proline content, soluble sugars and Cd concentration were significant (P <0.01). The highest amount of soluble sugars (0.48 mg kg-1), proline content (26.3 mmol g-1) and Cd concentration (0.685 mg) were obtained in 30 mg kg-1 of Cd and 0 μM SA. Also, the highest amount of soluble sugars (0.53 mg kg-1), plant length (44.6 cm), root length (19.6 cm), shoot dry weight (7.51 g), and leaf area (268.2 cm2) were found in the treatment of 500 μM SA and 0 mg kg-1 Cd.

The application of salicylic acid effectively increased the all measured growth parameters, including plant biomass, and total root volume. Cd stress reduced growth indices and, increased proline content and soluble sugars in tomato. Also, it seems that under Cd-induced stress, SA is an effective approach for improving crop growth by increasing plant resistance. In general, the application of appropriate concentration of salicylic acid (500 μM), as a plant hormone, is an effective, simple and low-cost strategy to reduce the adverse effects of Cd (30 mg kg-1 soil) stress in tomato.

Soil hydraulic conductivity (K) is an important parameter in designing drainage systems and estimating water flow in soils, Although some methods are suggested for direct measurements of saturated hydraulic conductivity (Ks) but they are usually time consuming and costly. Pedotransfer functions (PTFs) is a valuable tool and indirect method to predict the Ks from the available soil data. The purpose of this research was to derive the best PTF that can predict saturated hydraulic conductivity values from the available parameters in Abadan. After basic studies drainage include logging (determination of texture, color, resistance to drilling, stickiness and plasticity) and determination of watertable, saturated hydraulic conductivity was measured on the soil columns using Ernest auger hole method then by exact semidetailed soil survey, morphological characteristics such as structure were specified as well, some physical and chemical properties of soil were measured, Geometric mean diameter (dg) and geometric standard deviation of soil particles (dg) were calculated by the exist equations. The multiple linear and nonlinear regression methods were used to develop the pedotransfer functions by using soil structure class, geometric mean diameter (dg), porosity and depth. From these four pedotransfer functions which were derived , the results indicated that accuracy of the derived PTF with R2=0.955 can predict the saturated hydraulic conductivity well from these four parameters and it can be used for primary estimation in order to design of irrigated poject.

Since gypsum affects on the soil physical¡ chemical and biological properties¡ so the presence of gypsum on soil behavior¡ including soil texture¡ is important. The aim of this study was to compare methods of soil texture determination; touching (field)¡ leaching¡ Hydromer and Hess¡ in the soils of Khoda afarin plain¡ Ardebil province¡ with an area about 21000 ha. For this purpose¡ soil samples collected from 20 soil profiles¡ with three replications and a factorial experiment was conducted in a completely randomized design. The results showed that although the two methods of soil texture determination (leaching and Hess) had similar soil texture classes¡ but in the touching method¡ because large crystals of gypsum (sand sizes)¡ soil texture may be estimated more coarse. Also¡ Hydromer method resulted an error in measuring of soil texture¡ because the flocculation of fine particles. In the measuring by pre-treatment of BaCl2¡ the success of accurate estimation of soil texture depends on gypsum percent and particle size distribution of gypsum crystals. In the gypsum complete leaching method¡ soil texture class was usually heavier than other methods¡ so that¡ the variance analysis table showed that the effects of leaching and particles BaCl2 coating¡ on the soil particles percentage has been significant at 1% level. So¡ removing of gypsum in the precise measurement of soil texture is not correct¡ because gypsum constitute a major component of the solid material and remove it from the gypsic soils does not have a scientific justification and basis.

The calcification of soils and the effects of topography on this process were studied in semi-arid regions of Kermanshah. From a toposequence, based on the previous soil surveys of the region, five profiles were selected, and field studies and laboratory analyses were carried out on soils. Alluvial - colluvial fans, piedmont alluvial plains, and old plateaux were three main physiographies on the selected toposequence. Soil moisture and temperature regimes were Xeric and Thermic, respectively. The results indicate that redistribution of carbonates and soil formation processes may be categorized in four specific stages to be described in the text. Accumulation of calcium carbonates in soil profiles showed two basic forms: one in sandy layers of fine - textured soil profiles under the influence of abrupt textural changes and lower permeability, and the second in subsurface horizons of soils with calcareous parent material. The morphological evidences showed that in addition to translocation from upper horizons of carbonates by solution and suspension, physical movements to subsurface layers of fine calcareous materials have also affected the formation of calcic horizons. In other words, CaCO3 may have moved as fine particles through soil cracks and subsequently accumulated in the lower horizons. Soil mineralogy showed considerable amounts of illite, Chlorite, smectite and palygorskite clay minerals. Some pedogenic transformations of illite and chlorite may have caused formation of smectite and palygorskite.