نقش مقادیر مختلف سنگریزه بر برخی شاخص‌های کیفیت فیزیکی یک خاک لوم سیلتی

نوع مقاله: مقاله پژوهشی

نویسندگان

1 استادیار گروه علوم خاک دانشگاه ارومیه

2 دانشجوی کارشناسی ارشد گروه علوم خاک دانشگاه ارومیه

چکیده

در این پژوهش نقش مقدار سنگریزه‌ خاک بر شکل منحنی‌های مشخصه رطوبتی و مقاومت فروروی خاک بررسی شد. همچنین ارتباط شاخص‌های کیفیت فیزیکی خاک با مقدار سنگریزه مورد بررسی قرار گرفت. کلاس بافت خاک مورد مطالعه لوم سیلتی با 5 درصد وزنی سنگریزه اولیه با قطر 5 تا 20 میلی‌متر بود. از گلدان‌های بزرگ مجهز به سیستم زهکشی با ابعاد 50×40 و عمق 50 سانتی‌متر استفاده شد. آزمایش با 6 تیمار و 3 تکرار در قالب طرح کاملاً تصادفی در گلخانه دانشگاه ارومیه انجام شد. تیمارها شامل شش سطح 5، 10، 15، 20، 25 و 30 درصد وزنی سنگریزه با اندازه 5 تا 20 میلی‌متر بود. بعد از کشت گندم گلدان‌ها در فضای باز قرار گرفته و در طول آزمایش تمام تیمارها آب کافی از طریق آبیاری و بارندگی دریافت کردند. مقدار رطوبت خاک در نقاط مهم پتانسیلی خاک در تیمارهای مورد بررسی تفاوت معنی­داری داشت. بیش­ترین (cm3 cm-3 322/0) و کم­ترین (cm3 cm-3 269/0) مقدار رطوبت در مکش ماتریک hPa100 به ترتیب برای مقدار سنگریزه معادل با 10 و 30 درصد به دست آمد. افزایش سنگریزه باعث شد که مقاومت فروروی MPa 2 به عنوان مقدار بحرانی برای رشد ریشه گیاهان در رطوبت­های کمتری اتفاق بیفتد. رابطه معنی­داری بین مقدار رطوبت در مقاومت فروروی MPa 2 و مقدار سنگریزه بدست آمد. افزایش مقدار سنگریزه از مقدار طبیعی (5 درصد) به 30 درصد به ترتیب موجب افزایش بیش از 11 و 254 درصدی چگالی ظاهری (BD) و مدت زمان نفوذ آب در خاک (TI) شد.

کلیدواژه‌ها

موضوعات


عنوان مقاله [English]

Effect rock fragment Content on Some physical quality indices of a silt loam Soil

نویسندگان [English]

  • Hosein Asgarzadeh 1
  • Farrokh Asadzadeh 1
  • Parvin Khaleghi 2
1 University of Urmia
2 University of Urmia
چکیده [English]

This study was conducted to investigate the role of rock fragment content on water retention and soil penetration resistance curves as well as determining the correlation of soil physical quality indices with therock fragment content of the soil.A silt loam soil, containing 5% w/w 2 to 5 mm in diameter rock fragments, was used for this study. Experiment was carried out based on completely randomized design atsix treatmentsand three replications. The treatments including six levels of 5, 10, 15, 20, 25, and 30% w/w 2 to 5 mm in diameter gravel. Large drainable soil bins (40 cm × 50 cm with 50 cm depth) were used in this study. The bins were put outside (under natural conditions) after sowing of wheat (Triticum aestivumL.) and received enough amounts of water using irrigation and rainfall.There were significant differences (p<0.05) between the soil water content values in important matric suctions. The highest (i.e., 0.322 cm3 cm-3) and the lowest (i.e., 0.269 cm3 cm-3) means of water content at matric suction 100 hPa were obtained for the 10 and 30 percentage of the rock fragment content, respectively.Increase in rock fragment content of the soil significantly reduced the water content that the critical penetration resistance(2 MPa) happened. There was significant relationship between the water content of 2 MPa and rock fragment content of the soil. Increasing of the rock fragment from the normal value (5%) to 30% was causedthatthe bulk density and the infiltration time increase more than 11 and 254, respectively.

کلیدواژه‌ها [English]

  • gravel content
  • water retention curve
  • soil penetration resistance curve
  • soil physical quality indices
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