تعیین شایستگی مرتع با استفاده از شرایط محدود کننده روش فائو، به لحاظ تعدد عوامل و اینکه در برخی از موارد نیاز به عملیات آزمایشگاهی و تهیه نقشه دارد، زمان بر بوده و امکان قابلیت کاربرد آن توسط تمامی کارشناسان، وجود ندارد. از اینرو دستورالعمل طبقه بندی شایستگی مرتع برای چرای انواع دام در مناطق مختلف آب و هوایی، از طرف دفتر فنی مرتع پیشنهاد شد. بر اساس دستورالعمل پیشنهادی، شایستگی مرتع برای چرای انواع دام، از تلفیق سه معیار پوشش گیاهی (20 امتیاز)، آب (15 امتیاز) و فرسایش خاک (15 امتیاز) حاصل می شود. جهت ارزیابی قابلیت دستورالعمل ذکر شده در منطقه نیمه خشک، پژوهش حاضر در فصل رویش سال 1396 در مراتع کوهستانی امام کندی ارومیه انجام و نتایج حاصل از تعیین شایستگی تیپ های گیاهی بر مبنای دستورالعمل پیشنهادی با نتایج حاصل از روش شرایط محدود کننده فائو، توسط آزمون غیرپارامتری ویلکاکسون، مورد مقایسه قرار گرفت. نتایج نشان داد که در روش شرایط محدود کننده فائو، در 83 درصد موارد، معیار تولید علوفه، در 46 درصد، معیار حساسیت خاک به فرسایش، در 11 درصد، معیار منابع آب، به عنوان معیارهای کاهش دهنده شایستگی تیپ های گیاهی می باشند. ولی در دستورالعمل پیشنهادی، تنها حساسیت خاک به فرسایش، سبب کاهش امتیاز شاخص ها و در نتیجه، طبقات شایستگی شده است. نتایج نشان داد که تفاوت معنی داری بین دو روش از نظر طبقات شایستگی نهایی وجود ندارد (P≤0.05)، و بیش از 85 درصد از مراتع منطقه، در دو روش به صورت یکسان طبقه بندی شدند. بنابراین دستورالعمل پیشنهادی، قادر به شناسایی و تفکیک مناطق مستعد و غیرمستعد از نظر چرای گوسفند می باشد و کارایی آن در مقایسه با روش شرایط محدود کننده فائو، با توجه به صرفه جویی در هزینه و سادگی، قابل توجه است. این دستورالعمل، کارشناسان را قادر خواهد ساخت که در هنگام تهیه طرح های مرتعداری چند منظوره (تلفیقی)، با روشی ساده و کاربردی در عرصه، به تناسب استفاده از مراتع جهت چرای دام پی ببرند. پرونده مقاله

Rangeland degradation is one of the global concerns affecting the pastoralists and those who suffer from its negative environmental consequences. Grazing exclosure has been extensively used among the techniques implemented by the government to protect the fertility of threatened rangelands. The impact of exclosure has been a controversial issue; therefore, it is important to understand its effectiveness in restoring the degraded rangeland ecosystems. The goal of the present study was to evaluate the changes in some physico-chemical properties of soils following the grazing exclusion as compared to the adjacent grazed areas in three winter rangelands in Golestan province, Iran in 2011-2012. In each rangeland, ten soil samples were taken at the depth of 0–20 cm. Then in the laboratory, some soil properties such as soil texture, bulk density, porosity, saturated humidity, pH, EC, OM, total N, lime content, the amount of exchangeable Na+, K+, Mg++ and Ca++ were measured. Data of exclusion and grazed areas were analyzed using the independent T test in SPSS18 software. The results demonstrated that the establishment of exclosure had positive significant effects on the soil physico-chemical properties in Gomishan and Inchehbroun rangelands. So, a significant increase in the mean value of porosity, saturated humidity, OM and total nitrogen (p<0.05) as well as the significant decrease in bulk density and lime content (p<0.05) was observed in these rangelands. According to the results, the application of exclosure is recommended in Gomishan and Inchehbroun rangelands. پرونده مقاله

Plants may induce small-scale heterogeneity in soil nutrients, forming fertile islands. However, this process may depend on plant spices, plant developmental stages and habitat conditions. Vegetation cover in arid and semi-arid regions is mostly in the form of plant patches and bare soil of inter-patch areas, this form of vegetation cover can be useful to study plants impact on soil to get applicable knowledge for predicting plants efficiency in restoration projects. This study was conducted in 2016 to study some soil properties in vegetation patches of some halophytes from Urmia Lake, Iran. The results showed that soil EC decreased from10.32 (mS.cm-1) in bare soil to 4.92 (mS.cm-1) in vegetated areas. Also significant increase of soil pH and phosphorous content was observed in vegetation patches soil that were 8.73 and 29.61 (ppm) respectively in compare with bare soil that were 8.51 and 12.81 (ppm). As vegetation patches caused decrease in soil evaluated cations, so the main shoot succulent halophytes of Salsola dendroides, S. nitraria, S.iberica and Halocnemum strobilaceum which can uptake these ions were selected to measure their above ground biomass and root tissues content of these salts, the results showed significant difference between plant species in their salt uptake and accumulating ability. Halocnemum strobilaceum had the higher amount of sodium and magnesium in shoots that were 9.73 and 2.96 (mg.kg-1) respectively so it had the most ability to absorb these salts by roots and transporting them to shoots. In overall these plants can improve soil nutrients and chemical condition in their rhizosphere. پرونده مقاله

Most of rangeland soils are limited in their ability to supply adequate nutrients to plants. Soil conditioners have been shown to alter soil fertility and plant characteristics. This investigation aimed to evaluate the influence of two soil conditioner on nutrition value of N. schoberi and A. podolobus. For this, two separate experiments for each species were carried out in greenhouse using completely randomized design with three replications during 2018 and 2019. Treatments were four levels of wheat straw Biochar (WSB), as well as, lignite at rates of 0, 1.25%. 2.5% and 3.75% w/w added to clay loam soil. In the end of vegetative stage and before flowering, plant samples were taken and their Crude protein (CP) and Acid detergent fiber (ADF) content were measured and then Dry matter digestibility (DMD) and Metabolizable energy (ME) were calculated. Data were analyzed by One-way analysis of variance (ANOVA) and the means were compared using Duncan's test. The results demonstrated that WSB addition had no effect on nutrition value of both species. By application of Lignite, CP content of N. schoberi enhanced up to 44.45%, than that for control. The effect of lignite addition on nutrition value traits was high for N. schoberi. But this material had no effect on A. podolobus quality traits. Based on our findings, application of Lignite at 3.75 (w/w) recommended to improve soils of rangeland for cultivation of N. schoberi in dry-lands plantation projects or the conversion of dry lands to arable pastures. پرونده مقاله