Phosphorus, nitrogen and sediment losses from irrigated cropland and pasture grazed by cattle and sheep

Abstract

Grazing forage crops during winter can lead to soil physical damage and contaminant losses especially on Pallic soils prone to compaction and structural degradation. A site in North Otago (Timaru silt loam) with 2 years sheep and cattle grazing on winter forage crops and pasture was used to measure phosphorus (P) and nitrogen (N) losses in sub-surface (leachate from shallow lysimeters) flow and P losses in overland flow. Keywords: phosphorus, nitrogen, sediment, irrigation, overland flow, treading, grazing, pasture, crop land