Iranian Jornal of Watershed Management Science&Engineering

fa بررسی اثر کاربرد کوتاه‌مدت ترکیبی و جداگانه کمپوست، پلی‌آکریل‌آمید و پلی‌وینیل‌استات بر برخی ویژگی‌های خاک و تغییرات رواناب- رسوب نهشته‌های لسی Investigating the Effect of Combined and Separate Short-Term Application of Compost, Polyacrylamide and Polyvinyl acetate on some Soil Characteristics and Runoff-Sediment Changes in Loess Deposits تخصصي Special پژوهشي Research  فرسایش خاک از مهم‌ترین عوامل تهدید کمیت و کیفیت خاک محسوب می‌شود که پیامدهای ناخواسته آن را می‌توان به عنوان یکی از بزرگ‌ترین مشکلات امروزی زیست‌بوم‌های مختلف تلقی نمود. از مهمترین عوامل کنترلکننده رواناب و فرسایش خاک، کاربرد افزودنیهای خاک است.  بنابراین پژوهش حاضر، با هدف بررسی عملکرد جداگانه و ترکیبی از تأثیر کمپوست و پلی‌آکریل‌آمید و پلی‌وینیل استات بر برخی ویژگیهای شیمیایی، فیزیکی و زیستی خاک و همچنین تغییرات رواناب و رسوب نهشتههای لسی در آزمایشگاه شبیهساز باران انجام شد. برای انجام پژوهش حاضر تیمارهای حفاظتی در شرایط آزمایشگاهی و با استفاده از شبیهساز باران با شدت بارندگی 84 میلی‌متر بر ساعت و با تداوم نیم ساعته و کرتهای 2×1 متر با شیب نه درصد حدوداً متناسب با شرایط عمومی منطقه بر خاک لسی اراضی مرتعی منطقه قزقان دره شهرستان درگز  استفاده شد. نتایج نشان داد که استفاده از تیمارهای حفاظتی باعث افزایش زمان شروع رواناب، کاهش حجم رواناب و رسوب شده است که بیشترین کاهش حجم رواناب در تیمار ترکیبی کمپوست و پلی آکریل آمید به میزان 48 درصد مشاهده گردید. بیشترین و کمترین غلظت رسوب به ترتیب در دو تیمار شاهد و ترکیب کمپوست+پلی وینیل استات به ترتیب با مقادیر 267 و 5/48 گرم در لیتر مشاهده شد. بیشترین افزایش پارامتر بیومس میکروبی در تیمار ترکیبی پلی وینیل استات و کمپوست به مقدار 32 درصد میباشد در مجموع میتوان اظهار داشت که استفاده از کمپوست، پلی‌وینیل استات و پلی‌آکریل‌آمید آنیونی به صورت جداگانه و ترکیبی با هدف بررسی اثر آنها در حفاظت خاک و آب و خصوصیات شیمیایی و فیزیکی خاک، میتواند راهکاری مفید، کارا و مؤثر باشد.    Extended Abstract Introduction <pre style="text-align:justify">  Soil erosion is one of the most important threats to soil quantity and quality, and its unintended consequences can be considered one of the biggest problems facing various ecosystems today. The results of studies in Iran also indicate a high rate of soil erosion. Measurements and estimates show that the amount of water erosion in Iran is between one and four billion tons per year. Therefore, applying appropriate management methods to control soil erosion is of great importance in the management and conservation of natural resources. Since biological control and management of soil erosion and the use of native or non-native vegetation cover are very difficult or impossible in critical conditions and areas prone to erosion, among the various management measures available, it is necessary to use methods that can protect the soil in its place and in the first steps of the impact of erosive factors. One of the most important factors controlling runoff and soil erosion is the use of soil amendments. Therefore, the present study was conducted with the aim of investigating the separate and combined effects of compost, polyacrylamide, and polyvinyl acetate on some chemical, physical, and biological properties of soil, as well as changes in runoff and sedimentation of loess deposits in a rain and soil erosion simulator laboratory.</pre> <pre style="text-align:justify"> </pre> Materials and methods <pre style="text-align:justify"> The soil used in this research was collected from the surface layer (zero to 10 cm) of the loess soil of the pasture lands of Ghozghan Valley, Daregaz city which is sensitive to erosion. After being transferred to the laboratory, to maintain the relative stability of the soil grains, they were passed through a 4 mm sieve. Plots with width, length and height of one, two and 0.25 meters were used for this research. The desired slope of 9% was used, which is roughly proportional to the general conditions of the region. Then, to create an impermeable layer, the plots were filled with mineral pumice to a depth of 15 cm. In order to carry out the present research, compost treatment was used as an organic soil amendments, and polyacrylamide and polyvinyl acetate were used as inorganic soil amendments. Protective treatments were applied in laboratory conditions using a rain simulator with a rainfall intensity of 84 mm/h and with a duration of half an hour and plots of 1*2 m with a slope of 9%. In the review of sources from the researches, anionic polyacrylamide is used in the amount of six grams per square meter and in powder form due to its effect in reducing runoff and sediment, as well as polyvinyl acetate in the amount of six grams per square meter. Compost was used in the amount of 30 grams per square meter. </pre> <pre style="text-align:justify"> </pre> <pre style="text-align:justify"> Results and Discussion</pre> <pre style="text-align:justify"> The use of protective treatments prevented runoff from flowing on the surface of loess soil, resulting in an increase in runoff initiation time and a decrease in runoff and sediment volume. The highest reduction in runoff volume was observed in the combined compost and polyacrylamide treatment at 48%. The highest and lowest sediment concentrations were observed in the two control treatments and the compost  polyvinyl acetate combination, respectively, with values of 267 and 48.5 g/l. The results of the study treatments showed that the use of organic and inorganic compounds also had an effect on the biological properties measured, and these effects were both decreasing and increasing. The use of organic treatments such as compost had a positive effect on the biological properties of the soil due to its high organic matter content and it increases the activity of microorganisms and consequently increases parameters such as microbial biomass carbon, the largest increase being in the combined treatment of polyvinyl acetate and compost at 32%. The combination of compost can lead to improvement of the physicochemical and microbiological properties of the soil. The loss of three nutrients, nitrogen, phosphorus, and potassium, increased, especially in organic treatments compared to the control. Based on the results of this study, the best treatment was the simultaneous use of polyvinyl acetate and compost.</pre> <pre style="text-align:justify"> </pre> <pre style="text-align:justify"> Conclusion</pre> <pre style="text-align:justify"> The results of the treatments studied in this study showed that in general, applying organic and inorganic amendments separately and simultaneously reduced the amount of sediment. In general, regarding the effect of the treatments used in this study on the amount of soil loss, it can be said that modifying the physical and even chemical properties of the soil increases its resistance to erosion and erosive agents. Regarding the importance of physical and chemical properties of soil, it can be said that physical properties are more important and their modification is more important in reducing erosion; however, changing and modifying the chemical properties of soil by using various organic additives can also play a role in reducing erosion by affecting physical properties. Each of the organic and inorganic amendments studied was able to affect and change most of the measured parameters, while the simultaneous use of these compounds improved the effectiveness of these compounds in most cases. In summary, it can be stated that the use of compost, polyvinyl acetate, and anionic polyacrylamide, individually and in combination, with the aim of investigating their effects on soil and water conservation and soil chemical and physical properties, can be a useful, efficient, and effective solution. Finally, since the results of these experiments on a laboratory scale show good results, it can be suggested to carry out these treatments on a wider and farm scale.</pre> افزودنی‌های خاک, حفاظت خاک, رواناب, قزقان دره, خاک لسی. Soil amendments, Soil conservation, Runoff, Ghozghan Valley, Loess soils 1 16 http://jwmsei.ir/browse.php?a_code=A-10-1593-2&slc_lang=fa&sid=1 Aylin Pourazad آیلین پورآزاد aelin1385@gmail.com 100319475328460018956 100319475328460018956 No Ali Najafinejad علی نجفی نژاد najafinejad@gmail.com 100319475328460018957 100319475328460018957 Yes Department of Rangeland and Watershed Management, Faculty of Natural Resources, Gorgan University دانشگاه منابع طبیعی گرگان Maryam Azarakhshi مریم آذرخشی azar39m@gmail.com 100319475328460018958 100319475328460018958 No Department of Rangeland and Watershed Management, Faculty of Natural Resources دانشگاه تربت حیدریه Ali Mohammadian Behbahani علی محمدیان بهبهانی behbahani1383@yahoo.com 100319475328460018959 100319475328460018959 No Department of Rangeland and Watershed Management, Faculty of Natural Resources, Gorgan University دانشگاه منابع طبیعی گرگان