نوع مقاله : مقاله پژوهشی

نویسندگان

گروه علوم و مهندسی آب، واحد تبریز، دانشگاه آزاد اسلامی، تبریز، ایران

چکیده

تبخیر از سطح خاک را می‌توان عمده‌ترین بخش از اجزای بیلان بخصوص در مناطق خشک و نیمه‌خشک تلقی نمود که باعث هدررفت آب می‌شود. از طرفی کاربرد مالچ می‌تواند روشی مناسب در کاهش تبخیر و اصلاح الگوی مصرف آب بخصوص در فضای سبز شهری قلمداد شود. در تحقیق حاضر، اثر کاربرد لایه مالچ در سطح خاک به‌صورت لایه ضد تبخیر در سه خاک‌ با بافت متفاوت از سه نقطه از فضای سبز شهر تبریز بررسی شد. خاک‌ها درون لایسیمترهای کوچک با قطر و ارتفاع cm30 شامل cm 25 خاک و cm 3 مالچ قرار گرفتند. آزمایش در قالب طرح بلوک‌های کاملاً تصادفی با 5 تیمار، شامل تیمار شاهد یا فاقد لایه مالچ سطحی و چهار نوع پوشش مالچی شامل؛ شن ریز، کود دامی، تراشه‌های چوبی و ضایعات پتروشیمی در سه تکرار و به مدت day 20 روز انجام گرفت. نتایج حاصل از تجزیه واریانس در همه خاک‌ها نشان-دهنده اثر معنی‌دار در سطح یک درصد لایه مالچ سطحی بر مقدار تبخیر سطحی از لایسیمترها بود. همچنین نتایج نشان داد در خاک‌های لوم شنی منطقه عباس میرزا و خاوران، تیمار مالچ شنی به ترتیب با 2/69 و 9/66% و در خاک لوم رسی منطقه عینالی، تیمار خرده چوب با 70% باعث کاهش در تبخیر شدند و تیمار ضایعات پتروشیمی کمترین تأثیر را در کاهش مقدار تبخیر در هر سه نوع خاک مورد آزمایش نشان داد.

کلیدواژه‌ها

موضوعات

عنوان مقاله [English]

Effect of Mulch Types on Maintaining Soil Moisture in Different Areas of Landscape of Tabriz City

نویسندگان [English]

  • Ahad Molavi
  • Shahram Shahmohammadi-Kalalagh
  • Manouchehr Abdolmanafi

Department of Water Sciences and Engineering, Tabriz Branch, Islamic Azad University, Tabriz, Iran

چکیده [English]

Introduction: In arid and semi-arid regions, evaporation from the soil surface represents the major water balance component that causes losses of water. Reducing surface evaporation using mulches in surface soil can significantly help reduce irrigation losses and protect water resources. The aim of this study was to investigate the four types of mulch cover including fine sand, manure, wood chips and petrochemical waste in surface soil as an anti-evaporation layer in soils with different textures from three regions of Tabriz including Abbas Mirza Park in the south, Einali in the north and Khavaran in eastern Tabriz.

Methods: To investigate the evaporation rate, the soils were filled into small Lysimeters with a height and diameter of 30 cm (25 cm of soil and 3 cm of mulch). Lysimeters were inserted into the soil of the study area. The amount of evaporation was calculated in terms of changes in the weight of the micro-Lysimeter under field capacity condition. The amount of drained water from micro-Lysimeters (if any) was also collected and measured by the containers placed under them.

Results: By applying mulch on the soil surface, water consumption is significantly reduced due to the lack of contact of dry air and solar radiation to the soil surface. Also, due to the effects of flow slope, moisture movement from the depth to the soil surface, soil moisture in the presence of mulch is transferred to the soil surface by capillaries at a slower speed and as a result the moisture distribution in the soil is more uniform and the soil is more uniform. In the experimental period for all three soil types, the amount of evaporation was obtained in the following order: soil without surface mulch or control> petrochemical waste mulch> manure > wood chip > fine sand. The results of analysis of variance show a significant effect (at the level of 1%) of surface mulch layer on the amount of surface evaporation from Lysimeters all three types of soil. The average evaporation of Lysimeters with different surface mulch layer had a significant difference (Duncan test at 5% level) and the types of mulch reduced the average evaporation of Lysimeters in all three types of soil compared to the control treatment.

Conclusion: During the 20-day test period, the highest amount of cumulative evaporation from clay loam soil was 213 mm and sandy loam soils (Khavaran and Abbas Mirza parks) were in the next ranks with 148 and 143 mm evaporation, respectively. The reason for more evaporation in clay loam soil can be due to the stronger capillary effect and better supply of moisture to the evaporation surface (soil surface) in this soil. In the sandy loam soil of Abbas Mirza Park and Khavaran region, the maximum evaporation reduction in fine sand mulch was 69.2% and 66.9%, respectively. While in the clay loam soil of Einali region, the greatest amount of evaporation occurred in the surface mulch of wood chips and as much as 70%. In other words, among the studied treatments, sand mulch and petrochemical waste treatments had the highest and lowest efficiencies in reducing evaporation from soils with different textures, respectively.

Keywords: Fine sand; Manure; Petrochemical waste; Surface evaporation; Wood chips.

Acknowledgment: We are immensely grateful to “anonymous” reviewers for their comments on an earlier version of the manuscript.

Conflicts of interest: The authors of this article declared no conflict of interest regarding the authorship or publication of this article.

کلیدواژه‌ها [English]

  • Fine sand
  • Manure
  • Petrochemical waste
  • Surface evaporation
  • Wood chips