Document Type : Research Paper
Authors
1 PhD Student, Faculty of Agricultural Engineering and Technology, University of Tehran, Iran
2 Associate Professor, Faculty of Agricultural Engineering and Technology, University of Tehran, Iran
Abstract
High soil phosphorus (P) can increase the amount of runoff P and cause pollution of P in water bodies. In this paper, to select the best method between laboratory extracting and rainfall simulator method for determining environmental threshold level of P concentration was compared. For this purpose, surface soil was sampledfrom 30 points of Talkherood Watershed inEastern Azerbayjan with widely available P contents. After determining some of general properties, four soil P tests comprising Olsen, Mehlich-3, Iron oxide, and Soltanpour were used. Water soluble P in lab was measured and runoff soluble P of soils was determined with using rainfall simulator by applying 75 mm h-1 rainfallfor 30 minutes. Relationship between P concentrations determined by four methods with a) water soluble soil P, as P loss index, and b) runoff soluble P, showed that environmental soil P concentration can be estimated by both lab extracts and rainfall simulation methods for lime soils of this region. As the lab extracts method are easier and less time-consuming, this method is recommended for threshold concentration estimation. Since in iron oxide method, slope difference between the two split-lines was greater than other methods and high correlation coefficients were obtained for all of the methods, as a result iron oxide method is better than others for threshold concentration estimation of available P concentration. Since changing point for dissolved reactive P was seen in 0.36 mg l-1 concentration, as a result this concentration is lower than environmental P concentration for eutrophication phenomenon.
Keywords
- Hansen, N.C., C. Daniel, A.N. Sharpley and J.L. Lemunyon. 2002. The fate and transport of phosphorus in agricultural systems. Journal of Soil and Water Conservation, 57: 408-417.
- Hesketh, N. and P.C. Brookes. 1995. Development of an indicator for risk of phosphorus leaching. Journal of Environmental Quality, 29: 105–110.
- Ige, D.V., O.O. Akinremi, D.N. Flaten, B. Ajiboye and M.A. Kashem. 2005. Phosphorus sorption capacity of alkaline Manitoba soils and its relationship to soil properties. Canadian Journal of Soil Science, 85: 417–426.
- Kleinman, P.J.A., A.N. Sharpley, T.L. Veith, R.O. Maguire and P.A. Vadas. 2004. Evaluation of phosphorus transport in surface runoff from packed boxes. Journal of Environmental Quality, 33: 1413–1423.
- McDowell, R.W. and L.M. Trudgill. 2000. Developing a predictor for phosphorus loss from soil. In L.D. Currie (ed.) Best soil management practices for production pages 153–164. Fertilizer and Lime Res. Centre, 12th Annual Workshop, Palmerston North, New Zealand. 10–13 Feb. 1999. Massey Univresity, Palmerston North, New Zealand.
- McDowell, R.W. and A. N. Sharpley. 2001. Approximating phosphorus release from soils to surface runoff and subsurface drainage. Journal of Environmental Quality, 30: 508–520.
- Mehlich, A. 1984. Mehlich III soil test extractant: a modification of Mehlich II extractant. Communications in Soil Science and Plant Aanalysis, 15: 1409-1416.
- Murphy, J. and H.P. Riley. 1962. A modified single solution method for the determination of phosphate in natural waters. Analytica Chimica Acta, 27: 31-36.
- Nair, V.D., G.H. Willie and D. Chakraborty. 2013. An indicator for risk of phosphorus loss from sandy soils. IFAS Extension, 2: 1-3.
- Oliveira, M. and A.V. Machado. 2013. The role of phosphorus on eutrophication: a historical review and future perspectives. Environmental Technology Reviews, 2: 117-127.
- Olsen, S.R., C.V. Cole, F.S. Watanabe and L.A. Dean. 1954. Estimation of available phosphorus in soils by extraction with sodium bicarbonate. Environmental Science, 939: 1-19.
- Olsen, S.R. and L.E. Sommers. 1982. Phosphorus, in methods of soil analysis, Part 2. Madison, pages 403–430.
- Pote, D.H., T.C. Daniel, D.J. Nichols, A.N. Sharpley, P.A. Moore, D.M. Miller and D.R. Edwards. 1999. Relationship between phosphorus levels in three Ultisols and phosphorus concentrations in runoff. Journal of Environmental Quality, 28: 170–175.
- Pote, D.H., T.C. Daniel, A.N. Sharpley, P.A. Moore, D.R. Edwards and D.J. Nichols. 1996. Relating extractable soil phosphorus to phosphorus losses in runoff. Soil Science Society of America Journal, 60: 855–859.
- Sharpley, A.N. 1995. Dependence of runoff phosphorus on extractable soil phosphorus. Journal of Environmental Quality, 24: 920-926.
- Smith, D.R., K.W. King and M.R. Williams. 2015. What is causing the harmful algal blooms in Lake Erie? Journal of Soil and Water Conservation, 70: 27a-29a.
- Sims, J.T. 2002. Environmental soil testing for phosphorus. Journal of Production Agriculture, 6: 501–507.
- Soltanpour, P.N. and A.P. Schwab. 1977. A new soil test for simultaneous extraction of macro and micro-nutrients in alkaline soils. Communications in Soil Science and Plant Analysis, 8: 195-207.
- Thomas, G.W. 1996. Soil pH and soil acidity. Methods of soil analysis: part 3, chemical methods. 475–490 pages.
- Walkley, A. and L.A. Black. 1934. An examination of the Degtjareff method for determining soil organic matter and a proposed modification of the chromic acid titration method. Soil science, 37: 29-38.
- Wang, Y.J., T.Q. Zhanga, I.P. O'Halloranb, Q.C. Hua, C.S. Tana, D. Speranzini, I. Macdonalde and G. Patterson. Agronomic and environmental soil phosphorus tests for predicting potential phosphorus loss from Ontario soils. Geoderma, 241–242: 51–58.
- Wang, Y.T., I.P. OHalloran, T.Q. Zhang, Q.C. Hu and C.S. Tan. 2015. Phosphorus sorption parameters of soils and their relationships with soil test phosphorus. Soil Science Society of America Journal, 79: 672- 680.
- Yli-Halla, M., H. Hartikainen, P. Ekholm, E. Turtola, M. Puustinien and K. Kallio. 1995. Assessment of soluble phosphorus load in surface runoff by soil analyses. Agriculture Ecosystems and Environment, 56: 53–62.
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