Phosphorus sorption, accumulation and leaching

摘要: Arable land is a major diffuse source of P loads to surface waters. The main processes for losses from agricultural fields are erosion, runoff and subsurface leaching. To identify soils vulnerable losses, it necessary understand the behind these losses. This thesis mainly concerns influencing Phosphorus sorption accumulation were studied in laboratory evaluate how affect release P, which potentially can be leached. Furthermore, leaching undisturbed soil cores exposed natural conditions was studied. All studies performed on Swedish long-term fertility experiment, includes types common southern central Sweden, each with four levels. capacity ranged 6.0 12.2 mmol kg-1 correlated amounts oxalate extractable Fe Al soils. test values (STP) individual soils, but STP could not explain when different capacities considered. Instead, estimates saturation using ratio proved useful assessing release. Long-term inorganic fertilization 42 49 kg ha-1yr-1 more than 30 years caused down 40 cm depth profiles. Below this no differences properties found between fertilized non-fertilized Total lysimeters 0.03 1.09 either or saturation. greatest macropore flow dominated water transport, irrespective STP. In another soil, low capacity, high highest treatment. remaining subsoils influenced seemed act as sink reduced treatments.