نوع مقاله : مقاله پژوهشی

نویسندگان

1 دانشجوی کارشناسی ارشد گروه علوم خاک دانشکده کشاورزی دانشگاه ارومیه

2 دانشیار گروه علوم خاک، دانشکده کشاورزی دانشگاه ارومیه

3 استادیارگروه علوم خاک، دانشکده کشاورزی دانشگاه ارومیه

چکیده

به­منظور مقایسه رفتار جذب پتاسیم در خاک­های زراعی و غیر زراعی در منطقه خوی، آزمایشات جذب به­صورت بچبا 10 نمونه خاک زراعی و 10 نمونه خاک غیرزراعی در سری غلظتی پتاسیم mg L-1)150-0) در قدرت یونی 01/0 مولار CaCl2 انجام گرفت. پس از تعادل، مقدار پتاسیم باقی­مانده در محلول اندازه­گیری و منحنی­های کمیت به­ شدت (Q/I) رسم و پارامترهای ظرفیت بافری بالقوه پتاسیم ((PBCK، نسبت فعالیت تعادلی پتاسیم (AReK)، پتاسیم آسان قابل تبادل (∆K0)، نیاز استاندارد پتاسیم (SKR)، غلظت تعادلی پتاسیم (EKC)، پتاسیم سخت قابل تبادل (KX) و انرژی تبادلی پتاسیم (EK) از روی منحنی­های کمیت-شدت (Q/I) محاسبه شدند. نتایج مقایسه میانگین پارامترهای خاک­های زراعی و غیرزراعی نشان داد که مقادیر پارامترهایEKC، AReK و ∆K0 در خاک­های زراعی نسبت به مقدار آن­ها در خاک­های غیرزراعی مجاور کاهش معنی‌داری (p≤0.01) داشتند، به طوری که با روند کشت، میانگین مقدار AReK از 0188/0 به 0048/0  0.5(mol.L-1) و میانگین ∆K0 از 117/0 به 057/0 cmolc.kg-1 کاهش یافتند. مقدار متوسط پارامتر EKC در خاک­های غیرزراعی و زراعی به­ترتیب 91 و 34 میلی­گرم بر لیتر  و میانگین  PBCKبرای خاک­های زراعی 8/11 و غیرزراعی 7/7  cmolc.kg-1/(mol.L-1)0.5 به­دست آمد. در نهایت می­توان نتیجه­گیری کرد که خاک­های منطقه مورد مطالعه، به­طور نسبی دارای پتاسیم بالایی می­باشند، ولی مدیریت کشت منطقه و نحوه مدیریت کودی زارعین منجر به کاهش میزان پتاسیم در خاک و در نتیجه افزایش پارامترهای جذب در خاک‌های زراعی شده است.

کلیدواژه‌ها

عنوان مقاله [English]

Comparison of potassium sorption characteristics of cultivated and virgin soils in Khoy region

نویسندگان [English]

  • Hasan Peyghami Khoshemehr 1
  • Ebrahim Sepehr 2
  • HamidReza Momtaz 3

1 MSc Student, Department of Soil Science, Urmia University, Iran

2 Associate Professor, Department of Soil Science, Urmia University, Iran

3 Assistant Professor, Department of Soil Science, Urmia University, Iran

چکیده [English]

The present study was conducted to study of potassium sorption behavior of soil in Khoy region. Sorption isotherm was constructed in the laboratory by equilibrating and shaking 2.5 g soil with 25 ml of 0.01 mM CaCl2 containing 0-150 mg K L-1 as KCl for 24 h. After equilibrium, remaining concentration of potassium measured and potassium Quantity-Intensity (Q/I) curves and their parameters such as potassium buffering capacity (PBCK،( potassium activity ratio at equilibrium (AReK), readily exchangeable K (∆K0), standard potassium requirement (SKR), equilibrium potassium concentration (EKC) and energy of exchange (EK) were calculated. Mean comparison of paired soil samples indicated that the AReK, EKC and ∆K0 values of cultivated soils were significantly (p≤0.001) lower than those of virgin soils, indicating decreasing of potassium in the cultivated soils. As with cultivation, AReK mean decreased from 0.0188 to 0.0048 (mol.L-1)0.5 and ∆K0 mean decreased from 0.117 to 0.057 cmolc kg-1. Mean of equilibrium potassium concentration (EKC) in virgin and cultivated soils was 91 and 34 mg.l-1 respectively and PBC mean for cultivated and virgin soils measured 11.8 and 7.7 cmolc.kg-1/(mol.L-1)0.5 respectively. It was concluded that soils of studied region have relatively sufficient potassium for plants but cultivation and fertilizer management lead to a reduction in the amount of potassium in soils and increasing the adsorption parameters.

کلیدواژه‌ها [English]

  • Adsorption isotherms
  • Potassium
  • Quantity – intensity relationship
  • Potassium buffering
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