Abstract

Urine from farmed livestock contributes significant quantities of nitrate nitrogen (N) to water bodies, resulting in elevated phytoplankton and nuisance plant growth. Heavily nitrate-contaminated groundwater can impair animal and human health. Ammonia and nitrous oxide also emit from urine patches, especially in anaerobic soil conditions (Ledgard and Luo, 2008). Several N leaching mitigation treatments are being evaluated in the Lake Taupo catchment (Ledgardet al., 2007) with salt, fed as a diuretic to cows during winter, showing most promise in modelling research (Bryantet al., 2007). This is probably because leaching losses from urine patches decrease exponentially as the load of N in urine patches decreases (Ledgard, 2001).

DA, Costall, and K Betteridge

Proceedings of the New Zealand Society of Animal Production, Volume 70, Palmerston North, 296-298, 2010