Plan now to reduce nitrate leaching
With droughts affecting many parts of the country, the thought of nitrate leaching is probably the furthest thing on the
mind of farmers right now; however, once the rain arrives and soil moisture levels are restored, nitrate leaching will
soon become a problem.
Ballance Agri-Nutrients Head of Agro-Sciences, Warwick Catto, says that a range of methods can be used to reduce the
accumulation of nitrate in the soil and subsequently reduce the loss of nitrogen through leaching, such as the use of
feed pads, wintering barns and the popularly promoted option of nitrification inhibitors, such as DCn.
‘Nitrification inhibitors – granular and liquid – are currently being incorporated into the latest version of Overseer,
the software program that is used to prepare nutrient budgets, providing farmers with documentation of the remedial
effect of using such products.
‘However, all this is pointless if nitrification inhibitor applications are poorly timed,’ he says.
There has been significant money invested into the development of nitrification inhibitors, and Ballance has
commissioned AgResearch scientists to investigate the best ways of using these products in different parts of the
country.
‘One of the outcomes of this research has been the discovery that to get optimal results, you need to time product
application in line with your geographical location. This is related to the timing of the significant drainage events
in the district, and to the stock management practices in different parts of the country.’
Most nitrogen leaching occurs from May to September. Research indicates that on well-drained soils, for best results
DCn should be applied in April/May and July/August to cover the high-risk leaching period over winter and retain autumn
nitrogen in the system. On wetter soils best results are achieved from two applications of DCn around March and May, or
one application in April
Mr Catto explains that in Southland and Otago, the main nitrate leaching events tend to occur earlier in the year than
they do in Canterbury and the North Island. As a result, nitrification inhibitors should be applied earlier in order to
maximise the benefit from them.
For more information phone your local Ballance technical sales representative on 0800 222 090.
ENDS