Stratification, forms, and mobility of phosphorus in the topsoil of a Chromosol used for dairying
W. J. Dougherty A B F , D. M. Nash C , D. J. Chittleborough A , J. W. Cox D and N. K. Fleming EA Soil and Land Systems, School of Earth and Environmental Sciences, The University of Adelaide, SA 5005, Australia.
B New South Wales Department of Primary Industries, Locked Bag 4, Richmond, NSW 2753, Australia.
C Department of Primary Industries and eWater CRC, RMB 2460, Ellinbank, Vic. 3820, Australia.
D CSIRO Land and Water and eWater CRC, PMB 2, Glen Osmond, SA 5064, Australia.
E South Australian Research and Development Institute, GPO Box 397, Adelaide, SA 5001, Australia.
F Corresponding author. Email: warwick.dougherty@dpi.nsw.gov.au
Australian Journal of Soil Research 44(3) 277-284 https://doi.org/10.1071/SR05076
Submitted: 10 June 2005 Accepted: 10 February 2006 Published: 5 May 2006
Abstract
The forms and stratification of soil phosphorus (P) and their relationship to mobile forms of P were investigated in soils collected from a subcatchment used for grazing of dairy cattle in the Adelaide Hills, South Australia. Phosphorus in the soils was highly stratified. The concentration of calcium chloride extractable P in the 0–0.01 m increment was, on average, 5.7 times greater than in the 0.05–0.10 m increment. Organic P (% of total P) in the top 0.01 m was significantly (P < 0.001) related to soil P content such that low P soils (total P of ~600 mg/kg) had high proportions of Po (~65%), whereas high P soils (total P of ~2000 mg/kg) had low proportions (~25%) of Po. Runoff P from these soils was predominantly (86%) dissolved (i.e. <0.45 μm). There was a significant (P < 0.001) exponential relationship between Olsen P in the top 0.01 m and dissolved P concentration in runoff. The form of dissolved P in runoff from soil in repacked trays was also significantly (P < 0.001) related to soil P. Runoff from low P soils (high Po) had high proportions (>50%) of dissolved unreactive P (DUP), whereas runoff from high P soils (low Po) had low proportions of DUP (<10%). Ultrafiltration of runoff samples revealed that 94 and 65% of the dissolved reactive P and DUP, respectively, was subcolloidal (i.e. <1 nm). These results highlight the relationship between soil fertility, the forms of soil P, and the concentrations and forms of P mobilised in runoff. Such relationships need to be considered in further studies of P mobilisation and the subsequent development of strategies designed to reduce runoff P concentrations.
Additional keywords: organic P, pasture, colloid, Australia, ultrafiltration.
Acknowledgments
This research was funded by Dairy Australia. The suggestions of 2 anonymous reviewers are gratefully acknowledged.
Colwell JD
(1963) The estimation of phosphorus fertilizer requirements of wheat in southern New South Wales by soil analysis. Australian Journal of Experimental Agriculture and Animal Husbandry 3, 190–198.
| Crossref | GoogleScholarGoogle Scholar |
Curtin D,
McCallum FM, Williams PH
(2003) Phosphorus in light fraction organic matter separated from soils receiving long-term applications of superphosphate. Biology and Fertility of Soils 37, 280–287.
Fleming NK, Cox JW
(1998) Chemical losses off dairy catchments located on texture-contrast soil: carbon, phosphorus, sulfur, and other chemicals. Australian Journal of Soil Research 36, 979–995.
| Crossref | GoogleScholarGoogle Scholar |
Halliwell D,
Coventry J, Nash D
(2000) Inorganic monophosphate determination in overland flow from irrigated grazing systems. International Journal of Environmental Chemistry 76, 77–87.
Haygarth PM,
Hepworth L, Jarvis SC
(1998) Forms of phosphorus transfer in hydrological pathways from soil under grazed grassland. European Journal of Soil Science 49, 65–72.
| Crossref | GoogleScholarGoogle Scholar |
Heathwaite AL,
Haygarth P,
Matthews R,
Preedy N, Butler P
(2005) Evaluating colloidal phosphorus delivery to surface waters from diffuse agricultural sources. Journal of Environmental Quality 34, 287–298.
| PubMed |
Hens M, Merckx R
(2002) The role of colloidal particles in the speciation and analysis of ‘dissolved’ phosphorus. Water Research 36, 1483–1492.
| Crossref | GoogleScholarGoogle Scholar | PubMed |
Jones OL, Bromfield SM
(1969) Phosphorus changes during the leaching and decomposition of hayed-off pasture plants. Australian Journal of Agricultural Research 20, 653–663.
| Crossref | GoogleScholarGoogle Scholar |
McDowell RW,
Monaghan RM, Morton J
(2003) Soil phosphorus concentrations to minimise potential P loss to surface waters in Southland. New Zealand Journal of Agricultural Research 46, 239–253.
McDowell RW, Sharpley AN
(2001) Approximating phosphorus release from soils to surface runoff and subsurface drainage. Journal of Environmental Quality 30, 508–520.
| PubMed |
McLaughlin MJ,
Baker TG,
James TR, Rundle JA
(1990) Distribution and forms of phosphorus and aluminium in acidic topsoils under pastures in south-eastern Australia. Australian Journal of Soil Research 28, 371–385.
| Crossref | GoogleScholarGoogle Scholar |
Mundy GN,
Nexhip KJ,
Austin NR, Collins MD
(2003) The influence of cutting and grazing on phosphorus and nitrogen in irrigation runoff from perennial pasture. Australian Journal of Soil Research 41, 675–685.
| Crossref | GoogleScholarGoogle Scholar |
Murphy J, Riley JP
(1962) A modified single solution method for the determination of phosphate in natural waters. Analytica Chimica Acta 27, 31–36.
| Crossref | GoogleScholarGoogle Scholar |
Nash D, Murdoch C
(1997) Phosphorus in runoff from a fertile dairy pasture. Australian Journal of Soil Research 35, 419–429.
| Crossref | GoogleScholarGoogle Scholar |
Nash DM, Halliwell DJ
(1999) Fertilisers and phosphorus loss from productive grazing systems. Australian Journal of Soil Research 37, 403–429.
| Crossref | GoogleScholarGoogle Scholar |
Nelson PN,
Cotsaris E, Oades JM
(1996) Nitrogen, phosphorus, and organic carbon in streams draining two grazed catchments. Journal of Environmental Quality 25, 1221–1229.
Pote DH,
Daniel TC,
Nichols DJ,
Sharpley AN,
Moore PA,
Miller DM, Edwards DR
(1999) Relationship between phosphorus levels in three Ultisols and phosphorus concentrations in runoff. Journal of Environmental Quality 28, 170–175.
Saunders WM, Williams EG
(1955) Observations on the determination of total organic phosphorus in soil. Journal of Soil Science 6, 254–267.
Shand CA,
Smith S,
Edwards AC, Fraser AR
(2000) Distribution of phosphorus in particulate, colloidal and molecular-sized fractions of soil solution. Water Research 34, 1278–1284.
| Crossref | GoogleScholarGoogle Scholar |
Sharpley AN
(1995) Dependence of runoff phosphorus on extractable soil phosphorus. Journal of Environmental Quality 24, 920–926.
Sharpley AN
(2003) Soil mixing to decrease surface stratification of phosphorus in manured soils. Journal of Environmental Quality 32, 1375–1384.
| PubMed |
Steward JH, Oades JM
(1972) The determination of organic phosphorus in soils. Journal of Soil Science 23, 38–49.
Turner BL,
Kay MA, Westermann DT
(2004) Colloidal phosphorus in surface runoff and water extracts from semi-arid soils of the western United States. Journal of Environmental Quality 33, 1464–1472.
| PubMed |
Turner BL, Leytem AB
(2004) Phosphorus compounds in sequential extracts of animal manures: chemical speciation and a novel fractionation procedure. Environmental Science & Technology 38, 6101–6108.
| Crossref | GoogleScholarGoogle Scholar | PubMed |
Turner BL,
Mahieu N, Condron LM
(2003) The phosphorus composition of temperate pasture soils determined by NaOH-EDTA extraction and solution P-31 NMR spectroscopy. Organic Geochemistry 34, 1199–1210.
| Crossref | GoogleScholarGoogle Scholar |