The hydrological pathways enabling transport of potentially mobile phosphorus from agricultural land to receiving waters are examined. While surface runoff remains an important pathway of phosphorus loss, recent research demonstrates the potential for subsurface transport of phosphorus in macropore flow and from drained land. The forms of mobilized phosphorus differ according to the transport pathway. For grassland, dissolved phosphorus is transported in surface runoff but particulate phosphorus is proportionately more important in macropore and drainflow, especially during storm events. Tilled land generally shows high particulate phosphorus transport. Where livestock intensification has increased the rate of manure returns to land, there is clear evidence of enhanced phosphorus transport, both as incidental losses in surface runoff and through matrix or preferential now in subsurface pathways. Abbreviations: TP, total P; TPP, total particulate P; POP, particulate organic P; PIP, particulate inorganic phosphorus (adsorbed onto Fe/Al complexes and as Ca/Mg phosphate); TDP, total dissolved P; DIP, dissolved inorganic phosphorus (molybdate reactive phosphorus); DOP, dissolved organic phosphorus (may include phosphorus oxides); CSAs, critical source areas; VSAs, variable source areas; PSAs, partial source areas; FYM, farmyard manure; MAFF, Ministry of Agriculture, Fisheries, and Food.
Pathways of phosphorus transport
Times Cited: 0 Sharpley, AN Conference on Agriculture and Phosphorus Management - The Chesapeake Bay APR, 1998 PENN STATE UNIV, UNIVERSITY PK, PA