زمينه و هدف: فرسايش‌پذيري ذاتي خاک در برابر باد (SIWE)، حساسيت ذاتي ذرات تشکيل دهنده خاک در مقابل کنده شدن و انتقال، در مقابل فرسايش است. اندازه‌گيري فرسايش‌پذيري ذاتي خاک در برابر باد مي‌تواند به وسيله دستگاه تونل باد صورت بگيرد، که عموما پرهزينه، مشکل و زمان‌بر است. از طرف ديگر به دليل تغيير مداوم شرايط مختلف زراعي و اقليمي اين ويژگي نيز داراي تغييرات زماني و مکاني مي‎باشد. بنابراين برآورد SIWE به وسيله ابزار هوش مصنوعي مي تواند گامي مهم در برنامه ريزي عرصه هاي تحت فرسايش بادي باشد. در اين تحقيق، برآورد اين شاخص به کمک مدل الگوريتم ژنتيک در ترکيب با شبکه عصبي مصنوعي بررسي شد. روش پژوهش: در منطقه مورد مطالعه که بخشي از دشت الله آباد در استان قزوين در مجاورت استان البرز است، 72 نمونه از عمق 10 -0 سانتي‌متري سطح خاک برداشته شد. شاخص جزء فرسايش‎پذيري بادي خاک (EF) که درصد خاک‎دانه هاي با قطر کوچک تر از 84/0 ميلي متر است در نمونه‌ها تعيين شد. همچنين بافت خاک (درصد رس، شن و سيلت)، pH، EC و کربنات کلسيم معادل اندازه-گيري شدند. نمونه‌هاي خاک برداشته شده از مزرعه بعد از هواخشک شدن از الک 75/4 ميلي‌متري عبور داده شده و بر روي سيني دستگاه تونل باد بصورت صاف ريخته شد. سپس دستگاه تونل باد، بادي با سرعت ثابت 18 متر بر ثانيه و به مدت 10 دقيقه ايجاد نمود. با استفاده از وزن رسوبات جمع آوري شده در انتهاي تونل بعد از انجام آزمايش، SIWE تعيين شد. مدل الگوريتم ژنتيک در ترکيب با شبکه عصبي مصنوعي بر طبق الگويتم آموزشي لونبرگ - مارکوارت با توجه به متغيرهاي داراي همبستگي مثبت با SIWE به عنوان ورودي مدل، تهيه و تحليل شد. يافته ها: مقدار pH خاک بين 00/7 تا 81/8 متغير بود. مقادير قابليت هدايت الکتريکي از 84/0 تا 3/49 دسي زيمنس بر متر (dS/m) متفاوت بود. داده هاي اجزاء بافت خاک، نشان دهنده مقدار بيشتر رس در مقايسه با اجزاء سيلت و شن در خاک‌ها مي باشد. حداقل آهک (CCE) در خاک، 15/3 درصد و حداکثر آن، 52/30 درصد بود. فرسايش پذيري ذاتي خاک در برابر باد فقط با دو متغير قابليت هدايت الکتريکي و EF همبستگي معني دار داشت. مدل الگوريتم ژنتيک هيبريد با شبکه عصبي مصنوعي با دو متغير ورودي EF و EC تهيه شد. بررسي صحت و دقت مدل نشان داد که مقدار R2 در داده هاي سري آموزش 9 درصد با داده هاي سري آزمون اختلاف داشت و مقدار خطا (RMSE)،kg s m-4 62/1 بود. در داده هاي سري آموزش، R2 نتايج بدست آمده از مدل (805/0) بيشتر از داده‎هاي نتايج بدست آمده از سري آزمون (714/0) بود. اگرچه داده هاي آموزش از R2 بيشتري برخوردار بودند، لذا خطاي (RMSE) نتايج داده هاي آموزش از آزمون بيشتر بود و در سري آزمون، مدل داراي پراکندگي (GSDER) کمتري بود. نتيجه گيري: از نتايج بدست آمده مي‌توان نتيجه گرفت که شوري خاک و فاکتور جزء فرسايش‌پذير خاک از ويژگي‌هاي مهم خاک هستند که مي‌توانند به عنوان تخمين‌گر مناسب وارد مدل‎هاي برآورد فرسايش‌پذيري خاک شوند. همچنين دقت تخمين مدل تلفيقي الگوريتم ژنتيک با شبکه عصبي مصنوعي براي داده‌هاي سري آموزش نسبت به دقت مدل براي داده‎هاي سري آزمون بيشتر است. اما مدل براي داده‎هاي سري آموزش از خطاي بيشتري برخوردار است. مقايسه خطا، دقت و صحت مدل در برآورد فرسايشپذيري ذاتي خاک در برابر باد در مقايسه با مطالعات مختلف فرسايش خاک و خصوصيات فيزيکي و شيميايي خاک، مدل تلفيقي الگوريتم ژنتيک و شبکه عصبي از صحت و دقت مناسبي در پيشبيني و برآورد فرسايشپذيري ذاتي خاک در برابر باد برخوردار است. پرونده مقاله

پرونده مقاله

In this study, we investigated the effects of organic waste and moisture superabsorbent on the amount of available water and delay in moisture equivalent of permanent wilting point (PWP) in soil. In the first phase (soil incubation phase), 12 treatments were studied in a completely randomized design at the Soil Science Laboratory of Science and Research Branch, Tehran. The treatments consisted of 5 and 10% compost (mixture of municipale waste compost and cow manure); 5, 15 and 30 g/kg soil of zeolite and 2, 4 and 8 g/kg soil of moisture superabsorbents (A200). In the second phase (greenhouse phase), three treatments with the highest delay in permanent wilting point with a control treatment were selected as planting media and in a factorial experiment based on randomized complete block design, we studied the effect of planting substrate (four substrates) and irrigation period at three levels (48, 72 and 120 hours) on Aloysia citrodora growth. The results showed that the highest amount of FC moisture equivalent was related to the treatment with 8 g superabsorbent per kg soil. The highest delay in the permanent wilting point was for 8 g superabsorbent per kg of soil with a delay of 682 h. The highest total fresh weight of plant was observed in the treatment of 10 g of zeolite per kg of soil and 48 hours irrigation round with a mean of 9.47 g. In the superabsorbent treatment, leaf dry weight was higher than the control in 3 irrigation rounds. In general, the results showed that the addition of superabsorbent to the soil by delaying the plant's wilting point could save water use by increasing irrigation rounds. پرونده مقاله

Due to the econemic and envaironmental limitiation in the use of peat moss as a growth medium of ornamental plants, researchers seek an apporiate alternative in flower and plants industry. Zeolite because of the high capacity of water holding and cations enchange, has an ability in the replacement of peat moss. At this research, the posibility subtitution of peat moss by zeolite as a growth medium of Dracaena marginata was investigated. The control medium was a ratio 2:1 of peat: perlite that six levels of zeolite (0, 10, 20, 30, 40 and 50 % v/v) in replacement with peat were used in a compeletly randomized design. Some chemical and physical charactristics of growth media were measured including EC, pH, total nitrogen, organic carbon, C/N ratio, available phosphorus, potassium, calcium, magnesium, bulk density, porosity and field capacity. The plant growth parameters were also measured including height, stem diameter, leaf number, fresh weight of leaves, root and stem. The results showed the highest height of stem obtained in 10% v/v treatment of zeolite and stem height had not significant difference in compared with control in 40 and 50% v/v zeolite. Fresh weight of leaves was more than in the control in all zeolite treatments, and in other growth indices, 10% v/v treatment caused a better response of plant. The bulk density increased and the porosity decreased proportional to the increase in zeolite. Prosty, EC, aeration porosity and field capacity had the highest effect on the growth indices in 10-20% v/v zeolite. پرونده مقاله

Excessive accumulation of azolla in the wetlands of Guilan is currently an environmental problem. To this aim, a study was conducted to investigate the effect of Azolla compost on the growth medium of Zinnia ornamental plant. The treatment was a sandy loam soil and Azolla compost was replaced with 10, 20, 30, 40 and 50% by volume. The research was performed based on a completely randomized design with three replications and 54 pots. The chemical properties of the substrate including electrical conductivity, acidity, nitrogen content and phosphorus and potassium levels were measured. Growth indices including fresh and dry weight of leaves, stems, roots and flowers, and leaf chlorophyll content were also measured. Nutrient concentrations of nitrogen, phosphorus and potassium in the leaves of zinnia plant were measured. The results showed that the highest growth rate was observed in 20 and 30 % treatments of Azolla compost and the lowest growth rate was observed in control treatments. Azolla compost increased the concentration of nitrogen, phosphorus and potassium in the leaves, which indicated an increase in the quality of plant nutrition. Higher amounts of compost (40 and 50%) reduced plant growth indices compared to 20 and 30% compost treatments, but in the same treatments, plant growth was significantly higher than the control. In general, it can be concluded that Azolla compost can be used as a suitable organic matter in zinnia medium. پرونده مقاله

One of the important issues in sustainable agricultural management is the proper yeid of the agricultural products under environmental stress conditions. Naturally, in the dry country of Iran, lack of moisture is one of the main challenges of agriculture. Proper plant nutrition can moderate the effects of drought stress. To investigate the effects of drought stress on plant yield, Zinnia was used as a test plant. For this purpose, the growth of Zinnia plant in response to drought stress at different levels of potassium fertilization was investigated in a factorial experiment based on a randomized completely block design with two factors. The first factor: Three periods of irrigation including 2 days, 4 days, one week and the second factor: Four levels of potassium fertilizer including: 1) Use of potash fertilizer as base, 2) Use of potash fertilizer as base and during the growth period, 3) Use of potassium fertilizer as a base and during the growth period + 2 times foliar spraying, 4) Using potash fertilizer as base and during the growth period + 4 times foliar spraying. The cultivation medium was used in a 2:1 ratio of soil and manure in each pot. After the end of the growth period, the vegetative indicators include fresh and dry weight of aerial organs (shoot), plant height, number of lateral branches, number of flowers, flower weight, length of the longest branch were measured. The highest growth indices were: Fresh and dry shoot weight in treatment 4 and 2 days irrigation equal 2.36 and 0.33 g, respectively; plant height in treatment 4 and 2 days irrigation; the number of lateral branches in treatment 4 and 2 days irrigation equal 8; and the length of the longest branch in treatment 4 and 2 days irrigation equal 9 cm. The growth conditions in the fertilizer treatments were better than the control and this shows that potassium has increased the resistance of the plant to drought stress. پرونده مقاله