Possible Place For Nitrogen

Press, Volume CIX, Issue 32303, 22 May 1970, Page 6

Possible Place For Nitrogen

That there could be a place for use of artificial nitrogen fertiliser in New Zealand was clearly indicated by Dr L. Corkill, director of the Grasslands Division of the Department of Scientific and Industrial Research when he spoke to, the annual conference of the New Zealand Grassland Association at Lincoln College this week. But he added that in the main, and in the foreseeable future, it was probable that the grass-legume association would be thp basis of the country’s pastures for the clover plant had some advantages over grasses in nutritive value and was a relatively cheap source of nitrogen. “Even the best of our present pasture legumes may be incapable of supplying adequate nitrogen to enable associated grasses to reach the highest yield levels of which they are capable," said Dr Corkill. “To reach these levels, artificial nitrogen may be necessary. “Its use has been demonstrated where the requirement is increased pasture production during the winter and early spring, but it may have much wider, application. No doubt higher and more sustained pasture yields could be obtained by the use of artificial nitrogen

with grass alone, for, in general the better grasses are capable of higher sustained yields than the legumes—an exception to this generality is the high yield potential of lucerne in parts of Canterbury. “In the past very little work has been done in New Zealand on the role of artificial nitrogen in pastures because of its relatively high cost. However, with world production of nitrogen fertilisers increasing and prices decreasing, there is greater accent on their use. "Although it is well established that, in the short term, yields of grass-clover pastures can be raised by appropriate use of artificial nitrogen, there is need for basic work on the longterm effects of applied nitrogen on yield, pasture composition and rhizobial nitrogen production. “Information is needed on the pattern of response to nitrogen at different times of the year over a number of years, and on the integration of the use of artificial and rhizobial nitrogen to obtain maximum and well distributed pasture yields.”