Park, G. B.2025-07-152025-07-151994https://hdl.handle.net/10182/19217Pig slurry contains valuable nutrients which are beneficial to pasture growth. However environmental pressure has forced pig production units to determine whether or not the disposal of piggery wastes is polluting the groundwater or the atmosphere. Therefore this study was conducted to calculate the application rate of nitrogen per hectare and the quantities of lost via leaching, volatilisation and denitrification from a case study farm. The amounts of other nutrients being applied were calculated to ascertain whether long term applications of pig slurry increase the soil and plant nutrient status. This was achieved by taking a single slurry sample and analysing it for the N concentration. Using field measurements during application, the amount of slurry being applied per hectare was calculated. Then using the results from the slurry analysis and from other literature the application rate of nitrogen. Phosphorous, potassium and sulphur was also calculated. Values from the literature were used to calculate the quantity of N lost via leaching, volatilisation and denitrification. By conducting soil and plant analysis of five plots which had received slurry for 18, 10, 8, 2 and 0 years I was able to identify the effects of slurry on soil fertility and plant nutrition. I discovered that the case study farm applied on average 166 kg N/ ha, 70 kg P/ha, 118 kg K/ ha and 16 kg S / ha. Losses were calculated to be 5% (8 kg N/ ha) via leaching in the form of nitrate, 11% (18 kg N/ ha) via volatilisation in the form of ammonia gas and up to 35% (58 kg N/ ha) via denitrification in the form of nitrous oxide; these losses were below the acceptable levels at present . It was also found that soil retention of slurry N is around 12-15%. I discovered that losses may be able to be reduced by lowering the application rates to 80 kg N/ha and 100 kg N/ ha when pasture production is low in winter and summer respectively and maintain the application rate (160 kg N/ ha) when pasture production is high in either spring or autumn.enhttps://researcharchive.lincoln.ac.nz/pages/rightspig slurrypig productionnitrogen applicationDissertationDigital thesis can be viewed by current staff and students of Lincoln University only. If you are the author of this item, please contact us if you wish to discuss making the full text publicly available.ANZSRC::300407 Crop and pasture nutritionANZSRC::300302 Animal managementANZSRC::300411 Fertilisers (incl. application)