Abstract
The sorption and desorption of phosphorus (P) from eroding soil particles in land runoff are important processescontributing to agriculturally-driven eutrophication. We investigated the P-exchange properties and related
chemical characteristics of contrasting European agricultural soils and sediment material eroded from them under indoor (small-scale) and outdoor (larger-scale) rainfall simulations. Quantity-intensity (Q/I ) relationships
revealed large variation in equilibrium P concentrations at zero net P sorption (EPC0) (0–10.3 mg l−1) and instantly labile P (−Q0, the amount of P to be desorbed to obtain a P equilibrium concentration of 0 mg l−1) (2–75 mg kg−1), both correlating closely with Al-bound P and the P saturation degree of Al oxides (DPSAlox).Maximum P sorption (Qmax) (43–515 mg kg−1) also correlated most closely with Alox. The indoor and outdoor rainfall simulations produced sediments with different P sorption properties: in the indoor simulation (less
kinetic energy, constant slope), the sediments had larger EPC0 values, and usually larger −Q0 values, than the sediments in the outdoor simulation (greater kinetic energy, variable slopes). Furthermore, the P exchangeproperties of the sediments differed from those of the bulk soil depending on the enrichment of soil P-sorption components (Fe/Al oxides, clay). The outdoor simulation indicated that sites with gentle slopes produced sediments that were more enriched with Alox, Feox, Mnox and organic C than those with steeper slopes. In this
study, when the bulk soil had an initial EPC0 greater than 1.3 mg l−1, the outdoor rainfall simulation produced sediment with smaller EPC0 and vice versa, indicating that, depending on the P status of the bulk soil, the sediment material was acting as source or sink for P during transport. However, on the basis of their EPC0 values, most eroding sediments might be expected to desorb, rather than adsorb, P when entering surface water.
chemical characteristics of contrasting European agricultural soils and sediment material eroded from them under indoor (small-scale) and outdoor (larger-scale) rainfall simulations. Quantity-intensity (Q/I ) relationships
revealed large variation in equilibrium P concentrations at zero net P sorption (EPC0) (0–10.3 mg l−1) and instantly labile P (−Q0, the amount of P to be desorbed to obtain a P equilibrium concentration of 0 mg l−1) (2–75 mg kg−1), both correlating closely with Al-bound P and the P saturation degree of Al oxides (DPSAlox).Maximum P sorption (Qmax) (43–515 mg kg−1) also correlated most closely with Alox. The indoor and outdoor rainfall simulations produced sediments with different P sorption properties: in the indoor simulation (less
kinetic energy, constant slope), the sediments had larger EPC0 values, and usually larger −Q0 values, than the sediments in the outdoor simulation (greater kinetic energy, variable slopes). Furthermore, the P exchangeproperties of the sediments differed from those of the bulk soil depending on the enrichment of soil P-sorption components (Fe/Al oxides, clay). The outdoor simulation indicated that sites with gentle slopes produced sediments that were more enriched with Alox, Feox, Mnox and organic C than those with steeper slopes. In this
study, when the bulk soil had an initial EPC0 greater than 1.3 mg l−1, the outdoor rainfall simulation produced sediment with smaller EPC0 and vice versa, indicating that, depending on the P status of the bulk soil, the sediment material was acting as source or sink for P during transport. However, on the basis of their EPC0 values, most eroding sediments might be expected to desorb, rather than adsorb, P when entering surface water.
| Translated title of the contribution | Eurooppalaisten maiden ja niistä peräisin olevan sedimenttiaineksen fosforinvainto-ominaisuudet |
|---|---|
| Original language | English |
| Journal | European Journal of Soil Science |
| Volume | 61 |
| Pages (from-to) | 1033-1042 |
| Number of pages | 10 |
| ISSN | 1351-0754 |
| DOIs | |
| Publication status | Published - 2010 |
| MoE publication type | A1 Journal article-refereed |
Fields of Science
- 411 Agriculture and forestry
- 117 Geography, Environmental sciences