اثر کربنات کلسیم و pH بر سینتیک تثبیت فسفر در خاک های مختلف

نوع مقاله : مقاله پژوهشی

نویسندگان

1 دانشیار، دانشکدة مهندسی و فناوری کشاورزی، پردیس کشاورزی و منابع طبیعی، دانشگاه تهران

2 دانشجوی دکتری، دانشکدة مهندسی و فناوری کشاورزی، پردیس کشاورزی و منابع طبیعی، دانشگاه تهران

چکیده

در این بررسی آثار کربنات کلسیم و pH بر سینتیک تثبیت فسفر در چهار خاک غیرآهکی تیمار‌شده با سطوح متفاوت کربنات کلسیم خالص، همچنین، در شش خاک تنظیم‌شده با pH 5 تا 9 مطالعه شد. خاک‌ها قبل از آزمایش با K2HPO4 به میزان mgP/kg45 تیمار شد. سپس، در اینکوبیتور به مدت صد روز در دمای C○25 نگهداری شد. در زمان‌های مشخص از خاک‌ها نمونه‌گیری و غلظت فسفر در آن‌ها به روش Olsen اندازه‌گیری شد. نتایج نشان داد که واکنش فسفر با خاک‌‌ها دو فازی و متشکل از دسته‌ای از واکنش‌های سریع و دسته‌ای از واکنش‌های کند است. سرعت کاهش فسفر قابل‌استفاده (Olsen-P) در طول روز اول خیلی سریع، سپس تا پنجاه روز به تدریج کاهش یافت. بعد از آن در بسیاری از خاک‌ها به سمت صفر میل کرد. به‌علاوه، با افزایش درصد کربنات کلسیم در خاک‌ها، میانگین بازیابی فسفر به طور معناداری (در سطح 5 درصد) افزایش یافت. اما این اثر در همة خاک‌ها یکسان نبود، به‌طوری که در یک خاک افزایش درصد کربنات کلسیم تا 35 درصد هیچ تأثیری بر بازیابی فسفر نداشت. اثر pH بر قابلیت استفادة فسفر از روند معینی پیروی نکرد. در بعضی خاک‌ها افزایش pH از 2/5 به 8/8 اثر معناداری بر قابلیت استفادة فسفر نداشت، در حالی‌که در خاک‌های دیگر میزان Olsen-P در pHهای بالا به‌طور معناداری کمتر یا به‌عکس، بیشر از pH پایین بود. این آثار متفاوت pH در خاک‌ها را می‌توان به این صورت توضیح داد که تغییر pH در خاک باعث تغییر هم‌زمان چند عامل مرتبط با قابلیت استفاده از فسفر شامل حلالیت کانی‌های فسفر، ویژگی‌های باری سطوح جامد خاک، گونه‌گونه‌شدن فسفر محلول و تغییر نسبت غلظت یا فعالیت این گونه‌های فسفر و سرعت معدنی‌شدن فسفر آلی در خاک می‌شود. اثر خالص این تغییرات با تغییر pH در خاک‌های مختلف متفاوت است.

کلیدواژه‌ها

عنوان مقاله [English]

Effect of Calcium Carbonate and pH on the Kinetics of P Fixation in Different Soils

نویسندگان [English]

  • Hasan Towfighi 1
  • Mustafa Shirmardi 2
1 Ph.D. Candidate, Soil Science Engineering, Faculty of Agricultural Engineering and Technology, University of Tehran
2 Associate Professor, Soil Science Engineering, Faculty of Agricultural Engineering and Technology, University of Tehran
چکیده [English]

Effects of calcium carbonate and pH on the kinetics of P fixation were studied on four non-calcareous soils treated with different levels of pure CaCO3, and also on six soils which were adjusted for pH within the range of 5 to 9. Soils were also treated with K2HPO4 at the rate of 45 mg P/kg before they were incubated for a period of 100 days at 25○C. Soil samples were taken at certain predetermined times and the concentration of P measured through Olsen method. It became evident that the reaction of P with soil was biphasic, composed of a set of fast reactions vs a set of slow ones. The rate of reduction in available P (Olsen-P) was very fast during the first day, and then it gradually diminished for duration of 50 days, thereafter approaching zero in most of the soil samples. In addition, an increase in the level of CaCO3 content of the soils resulted in a significant (5% level) increase in the mean P recovery from the soils, however, the effect was not observed as the same in all the soils. It occurred that in one of the soils, an increase in CaCO3 up to 35% had no effect on P recovery. The effect of pH on P availability was not the same in different soils. In some soils an increase in the pH from 5.2 to 8.8 had no significant effect on P availability, while in others; the amount of Olsen-P was either higher or lower at higher pH values. The different effects of pH on P availability was explained by the variable effects of a change in pH on such available-P related parameters as solubility of P minerals, charge characteristics of the soil surface, speciation of soluble P and change in concentration or activity of P species and as well the rate of organic P mineralization. It was finally proved that the net effect of these changes, as a result of a change in pH, could be different in various soils.

کلیدواژه‌ها [English]

  • Available phosphorus
  • Calcium Carbonate Equivalent
  • Olsen
  • Recovery

مراجع

Afif, E., Matar, A., and Torrent, J. (1993). Availability of phosphate applied to calcareous soils of West Asia and North Africa. Soil Science Society of America Journal, 57, 756–760.
Anderson, G. (1980). Assessing organic phosphorus in soils. In The Role of Phosphorus in Agriculture. Eds. F E Khasawneh, E C Sample and E J Kamprath, pp 411-431. American Society of Agronomy, Madison, Wisconsin.
Awan, A. B. (1964). Effect of lime on availability of phosphate in Zamorano soils. Soil Science Society of America Proceedings, 28, 672-673.
Barrow, N. J. (1984). Modelling the effects of pH on phosphate sorption by soils. Journal of Soil Science, 35, 283-297.
Barrow, N. J. and Shaw, T. C. (1975). The Slow Reactions Between Soil and Anions: 2. Effect of Time and Temperature on the Decrease in Phosphate Concentration in the Soil Solution. Soil science, 119, 167-177.
Bertrand, I., Holloway, R. E., Armstrong, R. D., and McLaughlin M. J. (2003). Chemical characteristics of phosphorus in alkaline soils from southern Australia. Australian Journal of Soil Research, 41, 61-76.
Borrero, C., Pena F., and Torrent, J. (1988). Phosphate Sorption by Calcium Carbonate in some Soils of the Mediterranean Part of Spain. Geoderma, 42, 261-269.
Bouyoucos, G. J. (1962). Hydrometer  Method  Improved  for  Making Particle  Size  Analyses  of  Soils. Agronomy Journal, 54, 464-465.
Bubba, M. O., Arias, C. A., and Porix, H. (2003). Phosphorus adsorption maximum of sands for use as media in subsurface flow cultivated reed beds as measured by the Langmuir adsorption isotherms. Water Research, 37, 3390-3400.
Chen, Y. R., Butler, J. N., and Stumm, W. (1973a). adsorption of phosphate on alumina and kaolinite from dilute aqueous solutions. Journal of Colloid InterfaceScience, 43, 421-436.
Chen, Y. R., Butler, J. N., and Stumm, W. (1973b). Kinetic study of phosphate reaction with aluminum oxide and kaolinite. Environmental Science Technology, 7, 327-332.
Cole, C. V., Olsen, S. R., and Scott, C. O. (1953). The nature of phosphate sorption by calcium carbonate. Soil Science Society of America Proceedings, 17, 352-356.
Freeman, J. S. and Rowell, D. L. (1981). The adsorption and precipitation of phosphate onto calcite. Journal of Soil Science, 32, 75–84.
Griffin, G. F. (1971). Effect of liming on soil test level of phosphorus as determined by three methods. Soil Science Society of America Proceedings, 35, 540-542.
Griffin, R. A. and Jurinak J. J. (1973). The Interaction of Phosphate with Calcite. Soil Science Society of America Journal, 37, 847-850.
Havlin, J. L., Beaton, J. D., Tisdale, S. L., and Nelson, W.L. (1999). Soil Fertility and Fertilizers: an Introduction to Nutrient Management. 6th edition. Prentice Hall, Inc. Saddle River, New Jersey.
Haynes, R.J. (1982). Effects of liming on phosphate availability in acid soils. A critical review. Plant and Soil. 68: 289-308.
Holford I. C. R and Mattingly, G. E. G. (1975). The high- and low-energy phosphate adsorbing surfaces in calcareous soils. Journal of Soil Science, 26, 407-417.
Ibrahim, H. S. and Pratt, P. F. (1982). Effects of Rate of Application and Time on Phosphorus Sorption by Soils. Soil Science Society of America Journal, 46, 926-928.
Janghorbani, M., Roberts, S., and Jackson, T. L. (1975). Relationship of exchangeable acidity to Yield  and Chemical  Composition  of  Alfalfa. Agronomy journal, 67, 350-354.
Martini, J. A., Kochman, R. A., Siqueira, O. J., and Borkert, C. M. (1974). Response of soybeans to liming as related to soil acidity, AI and Mn toxicities and P in some oxisols of Brazil. Soil Science Society of America Proceedings, 38, 616-620.
Mokwunye, U. (1975). The influence of pH on the adsorption of phosphate by soils from the Guinea and Sudan savannah zones of Nigeria. Soil Science Society of America Proceedings, 39, 1100-1102.
Munns, D. N. and Fox, R. L. (1976). The slow reaction which continues after phosphate adsorption. Kinetics and equilibrium in some tropical soils. Soil Science Society of America Journal, 40, 46-51.
Murphy, J. and Riley, J. P. (1962). A modified single solution method for determination of phosphate in natural waters. Analytica Chimica Acta, 27, 31–36.
Murrmann, R. P. and Peech, M. (1969). Effect of pH on labile and soluble phosphates in soils. Soil Science Society of America Proceedings, 33, 205-210.
Nelson, R. E. (1982) Carbonate and Gypsum. P. 181-197. In Page, A. L. (ed.). Methods of Soil Analysis. Part 2. (2nd ed.). Agron. Mongor. 9. ASA and SSSA, Madison, WI.
Nelson, D. W. and Sommers, L. E. (1996). Total Carbon, Organic Carbon, and Organic Matter: Loss-on Ignition Method. P. 1004. In Sparks, D. L. et al.. (eds.). Methods of Soil Analysis. Part 3. 3rd ed. American Society of Agronomy, Madison, WI.
Olsen, S. L. and  Sommers, L. E. (1982). Phosphorus. P. 403–427. In: Page, A. L. (ed.). Methods of soil analysis, 2nd ed. ASA, Madison, Wisconsin, USA.
Oustan, Sh. and Towfighi, H. (2003). Prediction of Residual Available Phosphorus in Some Soils of Iran. Iranian Journal of Agricultural Sciences, 35,531-540.
Prasad, P. and Power, J. F. (1997). Soil Fertility Management for Sustainable Agriculture. CRC Press, New York, USA. pp. 171-209.
Rajan, S. S. S. and Fox, R. L. (1972). Phosphate adsorption by soils 1. Influence of time and ionic environment on phosphate adsorption. Communications in Soil Science and Plant Analysis, 3, 493-503.
Rennie, D. A. and Mckercher, R. B. (1959). Adsorption of phosphate by four Saskatchewan soils. Canadian Journal of Soil science, 39, 64-75.
Rhoades, J. D. (1978). Salinity: Electerical Conductivity and Total Dissolved Solids. P. 417-435. In Sparks, D. L. et al. (eds.). Methods of Soil Analysis. Part 3. (3rd ed.). American Society of Agronomy, Madison, WI.
Ryan, J. and Smillie, G. W. (1975). Liming in relation to soil acidity and P fertilizer efficiency. Communications in Soil Science and Plant Analysis, 6, 409-420.
Ryan, J., Hasan, H. M., Baasiri M., and Tabbara H. S. (1985). Availability and Transformation of Applied Phosphorus In Calcareous Lebanese Soils. Soil Science Society of America Journal, 49, 1215-1220.
Ryden, J. C., McLaughlin, J. R., and Syers, J. K. (1977). Time dependent sorption of phosphate by soils and hydrous ferric oxides. Soil Science, 28, 585-595.
Samadi, A. and Gilkes, R. J. (1999). Phosphorus Transformations and Their Relationships with Calcareous Soil Properties of Southern Western Australia.  Soil Science Society of America Journal, 63, 809–815.
Sharpley, A. N., Jones, C. A., Gray C., and Cole C. V. (1984). A Simplified Soil and Plant Phosphorus Model: II. Prediction of Labile, Organic, and Sorbed Phosphorus. Soil Science Society of America Journal, 48, 805-809.
Solis, P. and Torrent, J. (1989). Phosphate Sorption by Calcareous Vertisols and Inceptisols of Spain. Soil Science Society of America Journal, 53, 456-459.
Sparks, D.L. (1995). Environmental Soil Chemistry. Harcourt Brace and Company, San Diego, CA.
Stum, W. and Leckie, J. O. (1970). Phosphate exchange with sediments: its role in the productivity of surface waters. Proc. 5th International Water Pollution Research Conference (San Francisco) Rergamon Press. 1971.
Talibudeen, O. (1974). The nutrient potential of soil. Soil Fertility, 37, 41-45.
Wild, A. (1950). The retention of phosphate by soil. A review. Journal of Soil Science, 1, 221–238.
 

فایل ها

هم رسانی

ارجاع به این مقاله

آمار