جستجوی مقالات مرتبط با کلیدواژه « organic matter » در نشریات گروه « آبخیزداری، بیابان، محیط زیست، مرتع »

Perennial shrubs play a crucial role in shaping the soil quality within their habitats, influencing soil characteristics through leaf fall and root interactions. This study focuses on the impact of three native woody species-Acer monspessulanum, Prunus scoparia, and Daphne mezerum—on soil quality parameters in the ecologically sensitive and fragile Korkhangan rangelands of southern Yazd province. Considering the susceptibility of these rangelands to desertification, understanding the effects of woody plant species on soil quality is vital for successful rangeland rehabilitation and improvement projects.

The research investigates the qualitative characteristics of soil under the canopy of the three woody species compared to areas outside the canopy (control) in Korkhangan rangelands. Fifteen sites were selected, and soil samples were collected both under the canopy and outside the canopy at a depth of 0-5 cm. Soil physico-chemical parameters were measured in the laboratory, and statistical analyses (one-way ANOVA and Duncan tests) were employed to compare soil characteristics under the canopy and the control.

The study revealed variations in soil nitrogen, phosphorus, potassium, calcium, magnesium, organic matter, acidity, and electrical conductivity under different woody species. Acer monspessulanum demonstrated a significant influence on soil characteristics, with higher levels of nitrogen, phosphorus, potassium, calcium, magnesium, and organic matter compared to the control. The acidity of soils under D. mezerum, P. scoparia, and A. monspessulanum was lower than that outside the canopy. Additionally, electrical conductivity showed variations between A. monspessulanum, P. scoparia, D. mezerum, and the control.

The research underscores the distinct impact of native woody species on soil properties in the studied rangelands. Acer monspessulanum exhibited a particularly pronounced effect on soil characteristics. Understanding these relationships can inform effective planning for ecosystem improvement and development activities in rangeland areas.

 as one of the most critical environmental challenges in recent decades which has engendered environmental pollution worldwide (33, 3, 2), wind erosion occurs due to increased velocity and turbulence of the wind when blown on a cover-free surface (11), inflicting lots of economic and social damage on various sectors.There are several methods used to reduce wind erosion, including biological methods (seeding and planting), mechanical methods, and the methods used for strengthening the surface cover such as the application of different types of mulch (oil, polymer, biological, and mineral mulches) (21). In this regard, mulching should, as a last resort, be able to pass rainwater, penetrate into the ground, and maintain moisture while having sufficient required adhesive strength.Non-petroleum materials have increasingly been used in recent years to improve the stability of buildings, aggrandize the diameter of soil aggregates, and stabilize the soil against wind erosion. However, choosing a material as a soil stabilizer against wind erosion, replacing new mulch instead of oil mulch while considering the aforementioned factors, and taking the biodegradability of the non-petroleum materials into account are other crucially important factors to note in this regard. Therefore, this study sought to investigate the effect of mineral mulch (a combination of CaCl2 and MgCl2) on soil properties.

 The study area covered the sand dunes of the Rigboland desert located in Aran and Bidgol city, Isfahan. The mineral mulch used in the study was a stabilizing solution obtained from the evaporation of the brine of Iran’s central desert in the Khorobiabank region, known as the SS400 soil stabilizing solution (27). Chemical analysis of the solution indicated that it contained 30% CaCl2, 15% MgCl2, 5% NaCl, KCl, Ca (NO3) 2, and 50% water whose pH ranged between 5 and 6, with an average specific gravity of 1.5 g / cm3.On the other hand, in March 2012, mulch was sprayed directly to the natural field with three replications on three mounds of incomplete Barkhan-type sand dunes in Rigboland Aran and Bidgol regions to evaluate the influence of mineral mulch on soil’s chemical properties (Figure 4). To this end, samples of aeolian deposits were collected from three different depths of the hills in the study area with three replications (0-5 cm for the first replication with and without mulch; 5-10 cm for the second replication; and 10-20 cm for the third replication) prior to performing mulching. Finally, some samples were collected once more at the end of the experiment in May 2014 from the same three depths. It should be noted that 15,000 liters of mulch were applied per hectare.

 The results of paired T-test performed on the characteristics of different soil depths suggested that the mulched aeolian deposits did not differ significantly in both control and treatment groups in terms of N, CaSO4.2H2O, P, Cl, and OM characteristics in at all the depths studies (P> 0.01). However, the application of mineral mulch significantly increased the EC, pH, Ca, K, and CaCO3 at all depths, and N and Mg at the first and second depths (P <0.01).Mulches with different compositions and origins may increase or decrease the root's ability to absorb elements. In this regard, the current study found that mineral mulch significantly increased the soil’s pH (P <0.01), which could be justified if the Na and CaCO3 added to aeolian deposits as a result of applying such a mulch are taken into account.Furthermore, hydrolysis of Na and the dissolution of CaCO3 which eventually lead to the formation of hydroxyl anions could be regarded as the main cause of such an increase in the aeolian deposits’ pH under treatment mulch. Moreover, the comparison of the deposits’ pH made as a result of sampling with and without mulch revealed that the deposits’ pH would be higher if they are sampled with mulch, which can be justified according to the explanations provided above. On the other hand, some studies have reported that the aeolian deposits’ PH increased when treated with mulch (17), which is consistent with the results obtained in this study. However, the finding does not correspond with the results reported by some researchers (20 and 4).The significant increase in EC capability at different depths of the treatment group compared to those of the control group clearly confirms the influence of mulch on increasing the soil’s EC. Moreover, examining the soil’s EC capability at the evaluated depths showed a decreasing trend caused by the washing and transfer of the mulch-included solutes to lower depths, where the rate of ion transfer decreased with an increase in the soil’s depth.Also, mineral mulching significantly increased the soil’s K (P <0.01), which could be justified by considering the type and the origin of the mulch used, taking into account the fact that the initial solution was prepared by using the materials collected from the study area contained high amount potassium, a limited portion of which still remained active even after it was extracted from the solution (what remained from the solution afterward was used as mulch), causing a significant change in the amount of potassium in the soil. This finding is consistent with the results reported by some researchers (10, 13, and 14) who argued that mulch increased P and K in the soil.

 Considering the findings of this study in terms of the influence of mulch on the aeolian deposits’ componential elements and important chemical properties, including the deposits’ response, electrical conductivity, sodium absorption ratio, and the percentage of the exchanged sodium, all of which showed an increasing trend that led to salinization and alkalization of the deposits, and consequently to physiological dryness, and taking into account the fact that the mulch exerted no influence on the percentage of the aeolian deposits’ organic matter as the most important and effective factor in improving the physical, chemical, and biological conditions of the deposits, it could be argued that the mulch used in this study had no positive effect on the aeolian deposits studied. Therefore, this mulch is not recommended for stabilizing sand dunes and controlling dust.

Runoff is one of the major components of the hydrological cycle, which leads to soil loss from steep slopes and sediment production in watersheds. Investigation of effective factors in runoff coefficient is important in watershed management. The aim of this study was to investigate the effect of soil properties on runoff coefficient in Alanagh, Livar and Shekaralichay sub-basins in East Azarbaijan Province. After soil sampling, some physicochemical properties were measured and runoff data were obtained from the relevant stations. Based on the results, runoff coefficient in the studied sub-basins is affected by various soil properties such as particle size distribution, gravel, organic matter, lime, aggregate size and stability, and saturated hydraulic conductivity. As the percentage of sand and gravel increases and the percentage of clay and silt decreases, soil permeability increases and runoff coefficient decreases. Organic matter and lime are two important factors in the aggregate formation and stability, and improving the saturation hydraulic conductivity which plays a key role in reducing runoff production. The results of multiple linear regression analysis showed that runoff production in the Alangh sub-basin has a significant relationship with soil organic matter (r=-0.95, p<0.01) and bulk density (r=0.9, p<0.01). Organic matter content has the main role in runoff production in Livar sub-basin (r=-0.94, p<0.01) and Shekaralichay sun-basin (r=-0.95, p<0.01). Runoff coefficient in all sub-basins in the area is strongly related to organic matter content (r=-0.86, p<0.01), soil structure stability (r=-0.68, p<0.01) and stream density (r=0.49, p<0.01). This study showed that preserving and increasing soil organic matter can be an effective strategy in conserving rainwater and reducing runoff by improving soil structure and permeability.

The use of biochar as a soil amendment is one of the new methods to improve soil properties and increase plant yield. In this study, in order to evaluate the effect of adding natural biochar on soil properties and yield of Pamirian winterfat (Eurotia ceratoides) plant, an experiment in a completely randomized design were performed with 11 treatments by different levels of biochar (0, 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10% by weight) and three replications in greenhouse conditions. After the end of the growing season, some physical and chemical properties of the soil (pH, EC, organic matter (%), lime, bulk deisty, particle density, and porosity percentage), germination percentage, and yield of E. ceratoides were measured. In all the studied traits of the soil (except for the particle density), and the characteristics of the E. ceratoides plant, the statistical difference between the various levels of biochar was significant (a = 0.01). Adding different levels of biochar increased pH, ECy, soil porosity percentage, soil organic matter, whereas decrased bulk density, lime percentage, clay percentage, sand, and silt.

The aim of this study was to investigate the effect of Sufivand-manganese mine (located in Harsin city of Kermanshah province), on some soil characteristics, plant growth and some physiological traits of yellow milk-vetch (Astragalus parrowianus). Soil and plant samples of natural rangeland were taken in May around Sufivand mine at different distances namely in  the 100,500.1000,1500 and 2000 meters far from the mine respectively The statistical design of this project was performed based on a systematic random methodology in the five concentric circles around the Manganese mine. Six samples of soil and Astaragalus plant outside of manganese mine boundary (was not affected by mine) with the same edaphic and topographic conditions were sampled as a control treatment. The results of this project indicated that measured some physiological properties and plant growth were significantly affected by the distance from the Manganese mine. Hence, the maximum rate of root weight to canopy weight (0.85), transfer factor (1.9),    root density factor (4) and proline content (0.8 μmol / g) were significantly observed at (p 0.05) compared to the control treatment at a distance of 100 meters from the mine. The minimum stem length (12 cm), total nitrogen content (3%), essential oil content (0.2%), catalase activity (0.45 Units/mg) and peroxidase activity (0.2 Units/mg) at 100 meters distance from the mine were significantly different from the control at (p 0.05). It is concluded that the closer distance to the mine the more hazard of manganese to the Rangeland plants.

This research investigated the relationship between soil factors and under ground water level with distribution of Halostachys caspica pall. in saline, alkaline and semi-arid rangelands of Gomishan in Golestan Province. So that this region divided into three regions high dense, semi dense and without precence. In each region, 3 transects (100m) provided randomly. Then soil profiles were holed on onset, midle and the end of the transect in 0-30 and 30-60 cm systematically. Also under ground water level determined by digging some holes in three regions. Soil physicochemical factors and under ground water level compared in three regions high dense, semi dense and without precence by One-Way Anova and Duncan test. Also contrastive effect of depth and three regions analyzed by GLM test. The result indicated that there was a significant relationship on 1% level between three regions of high dense, semi dense and without precence of H. caspica in terms of sand, EC, pH, CaCo3, OM and SAR. Also there was a significant relationship on 1% level between soil physicochemical factors (exept CaCo3) in two depth. The result showed that all the soil physicochemical factors have significant contrastive effect on 1% level. Also the result showed that there was a significant relationship on 1% level between under ground water level in three regions. So that under ground water level in high dense region was more than the other two regions. On the whole the result showed that distribution of H. caspica would be more by increasing of sand percentage, EC, pH, CaCo3, OM, SAR and under ground water level.