Riddle, Matthew
- Department of Soil and Environment, Swedish University of Agricultural Sciences
Phosphorus derived from agricultural systems has been found to cause eutrophication of surface waters. To combat this, the specific location of soil profile P release is necessary for development of effective mitigation strategies. This paper describes a P leaching study of two Swedish arable soils, an organic (Typic Haplosaprist) and a mineral soil (Typic Hapludalf), both with high P content. Undisturbed soil columns isolated 0- to 20-, 20- to 40-, 40- to 60-, and 60- to 80-cm depth intervals. These were placed in a rainfall simulator and subjected to four 50-mm rainfall events to identify the origin of P leachate as a function of soil depth interval and physicochemical properties. Phosphorus losses were greatest from the two uppermost layers of both soils after 200 mm of artificial rainfall was applied at 5 mm h(-1). Total P concentration in leachate from the 0- to 20-cm layer ranged from 2.1 to 8.8 mg L-1 for the mineral and 3.7 to 10.3 mg L-1 from the organic soil, with most (95-100%) in dissolved reactive P form. Degree of P saturation correlated well with total P leaching losses from the organic soil (R = 0.84) but not the mineral soil (R = 0.69), suggesting that the presence of Al and Fe (hydr) oxides has a stronger influence on P leaching in the organic soil. Results indicate that both soils have the potential to contribute concentrations of P above those known to cause eutrophication of surface waters.
Journal of Environmental Quality
2018, volume: 47, number: 3, pages: 487-495
Publisher: AMER SOC AGRONOMY
Soil Science
https://res.slu.se/id/publ/96652