Soil Test Phosphorus and Clay Content Effects on Runoff Water Quality

Abstract

Dissolved phosphorus (P) in runoff increases with an increase in soil test P, but slopes found for this relationship vary by an order of magnitude. A difference in clay content contributes to this variation. Experiments were conducted on Ultisols of 5 and 32% clay by incorporating poultry (Gallus gallus domesticus) litter and triple superphosphate (TSP) to create a wide range in Mehlich 3‐extractable phosphorus (M3P). Mehlich 3 P increased similarly for the two sources with rate of P applied, but the increase was greater as clay content decreased. Total P in runoff was measured and it was related primarily to the quantity of sediment. Dissolved P (mg L−1) was measured with simulated rainfall and it increased with an increase in M3P (mg dm−3 in the surface 15–20 cm of soil). The slope of dissolved P versus M3P was 0.0040 for the 5% clay soil and 0.0014 for the 32% clay soil. With these relationships, M3P would need to be 250 mg dm−3 at 5% clay and 714 mg dm−3 at 32% clay to result in 1.0 mg L−1 dissolved P in runoff. Dissolved P in samples of runoff collected from natural rainfall with automatic samplers was substantially less than that with simulated rainfall. Thus, there was a marked difference due to method of measurement as well as the difference noted due to day content. Both factors should be considered if attempting to predict the level of dissolved P in runoff from soil test data.

Relationships Between Agronomic and Environmental Soil Test Phosphorus in Three Typical Cultivated Soils in China

“…Several studies have shown that dissolved P (DP) concentrations in runoff were highly related to soil P levels that were determined using the agronomical soil tests Sharpley et al, 1994;Kleinman et al, 1999;Cox and Hendricks, 2000). Andraski and Bundy (2003) reported that agronomic soil P tests, that are already widely available, could provide an adequate indication of DP concentration in runoff, and that specialized environmental soil P tests were usually not necessary.…”

Distributed hydrological modeling of total dissolved phosphorus transport in an agricultural landscape, part II: dissolved phosphorus transport

“…The fate and transport of P in the soil environment has been shown to be responsive to a broad range of abiotic and biotic processes (Frossard et al,2000), including: soil test P (Cox and Hendricks, 2000;McDowell and Sharpley, 2001); landuse (Beauchemin et al, 1996); tillage (Kingery et al, 1996); soil mineralogy and particle size distribution (Cox and Hendricks, 2000); erosion ; manure application (Beauchemin et al, 1996;Kleinman et al, 1999; Published by Copernicus GmbH on behalf of the European Geosciences Union. 264 W. D. Hively et al: Phosphorus transport in an agricultural landscape Kleinman and Sharpley, 2003); grazing (Smith and Monaghan, 2003); plant uptake (Koopmans et al, 2004); P mass balance and soil accumulation (Cassell et al, 1989); soil moisture and hydrology (McDowell and Sharpley, 2002b); soil type (Needelman et al, 2004) and management (Ginting et al, 1998;Klatt et al, 2003;Sharpley and Kleinman, 2003); temperature and precipitation (Correll et al, 1999); sorption kinetics (Morel et al, 2000;Schoumans and Groenendijk, 2000); and preferential flow and soil structure (Akhtar et al, 2003).…”

Environmental Mehlich-III soil phosphorus saturation indices for Quebec acid to near neutral mineral soils varying in texture and genesis

“…Several studies showed that soil texture, soil pH, soil genesis as related to mineralogy, Fe and Al oxyhydroxides, soil organic matter accumulation, as well as depth of water table could influence soil P sorption capacity, and quality of runoff and drainage water (Juo and Ellis 1968;Laverdière and Karam 1984;Giroux and Tran 1985;Breeuwsma and Silva 1992;Breeuwsma and Reijerink 1993;Simard et al 1994Simard et al , 2000Sharpley 1995;Sims et al 1998;Djodjic et al 1999;Cox and Hendricks 2000;Leclerc et al 2001). A useful environmental soil test P (STP) for assessing P accumulation should extract all or a representative amount of the P fraction in soils that is susceptible to surface runoff, leaching, or dissolution from eroded sediments, and be rapid, accurate, inexpensive and reliable (Moore et al 1998).…”