دانشگاه کاشان مهندسی اکوسیستم بیابان 2538-6336 15 50 2026 05 22 Investigation of the Effects of Mulch and Windbreak on Sorghum Growth and Weed Control Under Drought Stress بررسی تأثیر مالچ و بادشکن بر رشد و کنترل علف‌های هرز سورگوم تحت تنش خشکی 85 100 115449 ‎10.22052/deej.2026.258322.1138 FA جمشید شهاب دانشجوی دکتری مدیریت کنترل بیابان، دانشکده منابع طبیعی، دانشگاه یزد، یزد، ایران حمید سودائی زاده گروه مدیریت مناطق خشک و بیابانی، دانشکده منابع طبیعی، دانشگاه یزد، یزد ، ایران سید ابراهیم سیفتی گروه مدیریت مناطق خشگ، دانشکده منابع طبیعی، دانشگاه یزد، یزد، ایران کاظم کمالی گروه مدیریت مناطق خشک و بیابانی، دانشکده منابع طبیعی، دانشگاه یزد، یزد، ایران محمد علی حکیم زاده گروه مدیریت مناطق خشک و بیابانی، دانشکده منابع طبیعی، دانشگاه یزد، یزد، ایران Journal Article 2026 02 21 Introduction Sorghum is a highly productive forage crop, recognized for its adaptability to a wide range of soils and climatic conditions, its drought tolerance, and its suitability for use as both fresh and dry forage. Abiotic stresses, particularly drought, significantly limit agricultural productivity, especially in arid and semi-arid regions. To mitigate the effects of drought, strategies such as the use of drought-resistant species and mulching can be employed. Furthermore, the construction of windbreaks can help moderate the effects of strong winds. According to our background review, no research has been conducted on the simultaneous effects of mulch and windbreaks in reducing the negative impacts of drought stress on sorghum growth and weed control. The aim of this study is to investigate the effect of mulch and windbreaks on mitigating the negative effects of drought on sorghum, to classify different mulches based on their ability to alleviate stress-related damage, and to evaluate their role in weed control. Materials and Methods Seeds of the forage sorghum variety 'Speed Feed' were obtained from a reputable agricultural supplier. Sorghum was sown in early May 2025. Pre-planting mulch treatments—including black plastic, white plastic, straw, cardboard, and a control with no mulch—were applied. Drip irrigation was used throughout the experiment. Drought stress was applied at the six-leaf stage by maintaining soil moisture at three levels: 90%, 50%, and 25% of field capacity. To mitigate wind effects, sunflower windbreaks were planted one month before sorghum sowing and positioned perpendicular to the prevailing wind direction around the plots. Considering that the protective effect of grass windbreaks typically extends to 5–10 times their height, the distance between the sunflower row and the first sorghum plot was set at one times the final plant height in order to maintain the protective effect while minimizing shading and competition. Weed control was performed on three dates: 16 May 2025, 14 June 2025, and 9 July 2025. Forage sorghum was harvested at the soft-dough seed stage. Average plant height was measured in centimeters using a ruler. The fresh and dry weights of both shoots and roots were measured using a precision balance with an accuracy of 0.01 g. All data were analyzed using analysis of variance (ANOVA) in SPSS software, and means were compared using Duncan's multiple range test at a 5% probability level (α = 0.05). Result Mulch application, particularly white and black plastic mulch, significantly reduced weed density. Under severe drought stress conditions and in the absence of windbreaks, white plastic mulch reduced weed counts by 99.5%, 96.5%, and 98.68% on the three sampling dates, respectively, compared to the no-mulch control. Plastic mulches also produced the greatest reduction in weed biomass across all sampling dates. Plant height was likewise influenced by mulch type. Under severe drought stress and without windbreaks, white and black plastic mulches increased sorghum height by 37% to 76% across the five growth stages relative to the unmulched control. In addition, mulch treatments enhanced sorghum biomass. Under severe drought and without windbreaks, white plastic mulch increased shoot fresh and dry weight by 69% and 72%, respectively, compared to the control. Cardboard mulch also increased root fresh and dry weight by 72.9% and 72%, respectively. Overall, mulch application effectively alleviated the negative effects of drought stress by reducing weed infestation and significantly increasing sorghum height, as well as the fresh and dry weight of both shoots and roots. Discussion Drought stress significantly reduced both weed density and biomass. This effect was further amplified by mulch application, which significantly reduced weed density and biomass across all sampling dates, likely due to a shading effect that limits weed establishment and growth. Plant height also decreased significantly with increasing drought stress, likely as a consequence of reduced meristematic cell production under limited water availability. However, mulch application mitigated this effect and significantly increased plant height. By conserving soil moisture and improving water availability to plants, mulch enhances physiological processes critical for growth, such as cell turgor and cell division. Furthermore, plant height was greater in plots protected by windbreaks than in unprotected plots. Similarly, drought stress significantly reduced the fresh and dry weight of both roots and shoots by limiting plant-available water. Mulch application counteracted this reduction by reducing evaporation from the soil surface, thereby maintaining a more favorable soil moisture regime for sustained plant growth این تحقیق به‌منظور بررسی تأثیر کاربرد مالچ‌های سلولزی و پلاستیکی و بادشکن زنده بر کاهش اثرات منفی ناشی از تنش خشکی بر گیاه سورگوم و کنترل علف‌های هرز در شرایط مزرعه انجام شد. آزمایش به‌صورت فاکتوریل در قالب طرح بلوک‌های کامل تصادفی با سه تکرار طی سال 1404 اجرا شد. فاکتورهای مورد بررسی شامل سه سطح تنش خشکی (90، 50 و 25 درصد ظرفیت مزرعه) و 5 مالچ (شاهد، مالچ کاه، مالچ کارتن، مالچ پلاستیک سفید و مالچ پلاستیک سیاه) و دو تیمار بادشکن شامل بادشکن و بدون بادشکن بودند. نتایج بررسی نشان داد کاربرد مالچ به‌خصوص مالچ پلاستیکی تعداد علف‌های هرز را کاهش داد به‌طوری‌که مالچ پلاستیک سفید در 3 تاریخ مختلف تعداد این گیاهان را 5/99%، 5/96%، 68/98% نسبت به تیمار بدون مالچ تحت تنش خشکی شدید و در تیمار عدم وجود بادشکن کاهش داد. استفاده از مالچ‌های پلاستیکی سفید و سیاه در تیمار تنش خشکی شدید و عدم وجود بادشکن، ارتفاع سورگوم را در پنج مرحله از رشد بین 37 تا 76 درصد در مقایسه با تیمار بدون مالچ افزایش داد. مالچ پلاستیک سفید وزن‌تر و خشک گیاه را به‌ترتیب 69% و 72% و مالچ کارتن وزن‌تر و خشک‌ریشه را به‌ترتیب 9/72 % و 72% نسبت به تیمار شاهد (بدون مالچ) تحت تنش خشکی شدید و عدم وجود بادشکن افزایش داد. به‌طورکلی کاربرد مالچ اثرات منفی ناشی از تنش خشکی را کاهش داده و ضمن کنترل علف‌های هرز، منجر به افزایش ارتفاع، وزن‌تر و خشک اندام هوایی و ریشه سورگوم گردید.

https://deej.kashanu.ac.ir/article_115449_f0bc2c081a78a5f74dff995930f74a16.pdf