Phosphorus Leaching from an Organic and a Mineral Arable Soil in a Rainfall Simulation Study

Abstract

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. Total P concentration in leachate from the 0- to 20-cm layer ranged from 2.1 to 8.8 mg L for the mineral and 3.7 to 10.3 mg L 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 ( = 0.84) but not the mineral soil ( = 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.

Effect of anisotropy on solute transport in degraded fen peat soils

“…For most soil cores from the drained site, a high phosphate concentration (approximately 2 mg P l −1 ; Figure ) was observed in the leachate. The high P leaching concentrations are in consistent with recent studies by Parvage, Ulén, & Kirchmann () and Riddle et al (), who observed a range of phosphate concentrations in the effluent from 0.36 to 10.3 mg P l −1 for organic soils. For the studied fen peat, the redox sensitive P accounts for only <4% of total P, which is a small fraction if compared to values reported in other studies (>15%; Forsmann & Kjaergaard, ).…”

Phosphorus Speciation in Long-Term Drained and Rewetted Peatlands of Northern Germany

“…The lower concentration of plant available P at the subsurface than surface horizons and lack of significant differences at the subsurface horizons indicated that P translocation from the surface to the subsurface horizons was negligible or the leached P lost from the soil profiles. Other researchers reported the danger of P leaching from the surface to subsurface horizons of peat soils upon rewetting [14,40]. The disagreeing results can be attributed to variations in current land use, soil organic matter content, and predominant P species or experimental approaches, and peatland types.…”

“…Many previous studies reported that rewetting increased P solubility and mobility in soils [13,14,40]. These studies, however, investigated the effect of anaerobic conditions on degraded fen peat that was previously P-enriched by fertilization.…”

Understanding Organic Nonpoint‐Source Pollution in Watersheds via Pollutant Indicators, Disinfection By‐Product Precursor Predictors, and Composition of Dissolved Organic Matter

“…Nonpoint‐source pollution based on rural and agricultural organic matter receives less attention than pollution caused by point sources such as domestic sewage and industrial wastewater and from nutrients such as nitrogen and phosphorus (Sun et al, 2016; Riddle et al, 2018). Rivers in rural and agriculture‐dominated watersheds collect various pollutants, especially organic matter, from diverse sources.…”