Presentation on theme: "Reducing Nitrogen Losses from Agriculture Using a Nitrification Inhibitor (eco-n) Professor Keith Cameron, Professor Hong Di and Dr Jim Moir Centre for."— Presentation transcript:
Reducing Nitrogen Losses from Agriculture Using a Nitrification Inhibitor (eco-n) Professor Keith Cameron, Professor Hong Di and Dr Jim Moir Centre for Soil and Environmental Quality Lincoln University, Canterbury New Zealand
Two main nitrogen losses from agriculture Nitrate leaching in drainage water causes pollution of surface and groundwater Nitrous oxide (N 2 O) is given off by soil and is a potent greenhouse gas. NZ agricultural greenhouse gases
How do you measure nitrate leaching losses from a grazed pasture?
Underground laboratory constructed to house lysimeters under typical soil and environmental conditions
Surface of lysimeters level with surface of paddock. Typical rainfall, temperature, irrigation, fertiliser, pastures, and urine applied.
Going downstairs into the underground laboratory
Drainage water is collected in the underground laboratory to measure nitrate leaching losses directly from soils.
Robotic cow hoof used to simulate trampling during grazing
Results show that in dairy farming urine patches are the main sources of nitrate leaching and nitrous oxide emissions
Most nitrate leaching comes from urine patches not from fertiliser Ledgard et al, 2005
Improved nitrogen management is now possible with the newly developed eco-n nitrification inhibitor.
NH 4 + - - NO 3 - Cation exchange Nitrate ions (NO 3 - ) are not held by soil particles and can easily be leached when drainage occurs The Nitrogen Cycle (McLaren & Cameron, 1996)
NH 4 + - - NO 3 - Cation exchange Nitrification inhibitor ‘eco-n’ slows down the rate of nitrate production and thus reduces the nitrate leaching loss The Nitrogen Cycle (McLaren & Cameron, 1996)
The inhibitor temporarily reduces the activity of the nitrosomonas bacteria in the soil (Bacteriostatic effect)
Nitrification inhibitor (‘eco-n’) is applied as a fine suspension spray to improve soil N cycle efficiency and reduce the risk of nitrate leaching
Eco-n is applied in May and July/August because most losses occur between late autumn and early spring Drainage eco-n
HAMILTON: Mean Soil Temperatures (at 10 cm) and Estimated Drainage (mm) 0 20 40 60 80 100 120 JanFebMarAprMayJunJulAugSepOctNovDec Months Estimated Drainage (mm) 0 2 4 6 8 10 12 14 16 18 20 Soil Temperature ( 0 C) Drainage Soil Temp (C) Drainage eco-n In North Island Eco-n is applied in May and July because leaching also occurs in the winter/early spring
Decrease in nitrous oxide emissions Increase in annual farm pasture production Decrease in nitrate leaching Research results show:
Eco-n is based on New Zealand research trials published in internationally peer reviewed science journals 1.Di HJ and Cameron KC (2002) Soil Use and Management 18: 395-403. 2.Di HJ and Cameron KC (2003) Soil Use and Management 19: 184-290. 3.Di HJ and Cameron KC (2004a) Soil Use and Management 20: 2-7. 4.Di HJ and Cameron KC (2004b) NZ Journal of Agricultural Research 47: 351-361. 5.Di HJ and Cameron KC (2004c) Australian Journal of Soil Research 42: 927-932. 6.Di HJ and Cameron KC (2005) Agriculture, Ecosystems and Environment 109: 202-212. 7.Di HJ and Cameron KC (2006) Biology and Fertility of Soils 42: 472-480. 8.Di HJ, Cameron KC and Sherlock (2007) Soil Use and Management 23: 1-9. 9.Moir JM, Cameron KC and Di, HJ (2007) Soil Use and Management 23: 111-120. 10.Clough TJ, Di HJ, Cameron KC, Sherlock, RR, Metherell AK, Clark H and Rys, G (2007) Nutrient Cycling in Agroecosystems 78: 1-14. 11.Di HJ and Cameron KC (2007) Nutrient cycling in Agroecosystems 79,281-290. 12.Di HJ and Cameron KC (2008) Australian Journal of Soil Research 42: 927-932.
Lincoln University would like to thank Ravensdown Fertiliser Co-operative Ltd, and the Pastoral Greenhouse Gas Research Consortium (PGGRC) for funding this research.