The potential effectiveness of eco-n nitrification inhibitor in reducing nitrification rates in a range of key New Zealand dairy pasture soils: A dissertation submitted in partial fulfilment of the requirements for the degree of Bachelor of Agricultural Science with Honours

Increasing public concern over nitrate leaching from intensive agriculture, has led to a demand for accurate scientific research into nitrate leaching losses and the development of mitigation strategies to inhibit the detrimental effects of nitrate leaching on the environment and human health. Recent research has focussed on nitrification inhibitors as an on-farm mitigation tool to reduce nitrate leaching. This study looks at the potential effectiveness of the nitrification inhibitor eco-n at reducing nitrification rates in six different soil types from key dairying regions of New Zealand (Northland, Waikato, Bay of Plenty, Taranaki, West Coast of the South Island and Southland) when incubated at 10°C. Incubation vessels (10 cm diameter by 15 cm height) were packed with 4 mm sieved soil from the different regions and treated with plus or minus eco-n nitrification inhibitor. The experiment included five replicates of each treatment for each soil type, with the Northland soil type experiment also replicated at 15°C. Eco-n application had a highly significant (P