In the cold of winter, when feed is short, it's tempting to throw on a bit of nitrogen to make the grass grow.

However, unless conditions are suitable for grass growth, it will be money wasted as nitrogen is a growth accelerator, says Balance Agri-nutrients research and development manager Warwick Catto.

'Nitrogen will not start grass growth, it will only boost growth that is already occurring. Soil temperature, soil moisture, and soil structure must all support growth if nitrogen fertiliser is going to have any real benefit,” says Warwick.
'For late winter use, wait until soil temperatures exceed 5 degree Celsius before considering nitrogen fertiliser, and allow six weeks for the pasture to respond.”
He advises against applying nitrogen fertiliser to water-logged soils or when heavy rains are due. If the soil is saturated, the grass will not be growing. And, if a lot of rain is expected, the nitrogen fertiliser can simply be washed away through leaching.
'It is also important to remember that more is not necessarily better when it comes to nitrogen applications.
'For pasture, 30 kg N/ha is normally a suitable rate to apply, especially where growth rates are low.
'Winter is also when nitrate leaching becomes a concern.”
Most of the nitrate in the soil has come not from fertiliser applications, but from animal urine, so stock management practices play an important part in minimising leaching. Restricted or on-off grazing, using feed pads and wintering barns will all help to reduce the nitrogen loading on the soil, and so help reduce nitrate leaching.”
Having a nutrient management plan in place, as part of good agricultural practice, is one of the best things a farmer can do to understand where the losses come from and options to manage that nitrogen loss. This includes rates and timing of nitrogen, spelling intervals, on-off grazing strategy and how that influences nitrogen loss, Warwick says.
While farms probably won't be able to use the DCD nitrogen inhibitor this coming spring, Warwick says DCD is just one of the tools in the toolbox for managing nitrogen losses, and through investment in research and development, the company is exploring further mitigation tools.