Stage Set For Greater Production

Press, Volume CVIII, Issue 31832, 9 November 1968, Page 9

Stage Set For Greater Production

In a world in which first-grade cropping land was in very short supply it did not seem reasonable that a specialist agricultural country like New Zealand could afford to use its first-class land almost entirely for pastoral production, said Professor F. C. Crofts, professor of agronomy at the University of Sydney, in Christchurch this week, discussing the possible role of nitrogenous fertilisers in this country.

That New Zealand had been •ble to do this was a tribute to the high level of efficiency achieved in the production of animal products, but it was unlikely that even a high level of efficiency in this field could be a permanent substitute for more intensive production from cropping. Professor Crofts, who is at Massey University, said that since he had arrived in New Zealand in August he had been travelling in both the North Island and the South Island trying to get some idea of current productivity and of the potential for Increased production with the use of more intensive prac-

tices, such as increased use of nitrogen fertilisers and irrigation. In the most recent season, which had been a poor one for spring growth, Professor Crofts said, he had noticed that spring pasture growth had been severely limited by nitrogen deficiency as was the case in Australia. It was nevertheless, appreciated that the problem of economically correcting this deficiency by obtaining higher animal production, from pastures was a problem that was specific to each particular agricultural environment and because of this there was no simple means by which New Zealand could cash in on low cost supplies of nitrogen that were becoming available. He was, however, sure that further research on the possible use of nitrogen fertilisers would delineate avenues where they could be used, along with other essential nutrients to greatly increase the output of grass and meat and dairy products. It also appeared that the scope for nitrogen in making more intensive cropping possible and profitable without reducing soil fertility was very great indeed. Nevertheless the need for nitrogen with crops appeared to be closely related to the intensity of cropping desired by the farmer.

There was no doubt that legume-based pastures provided adequate nitrogen for one or two crops in a rotation but it could well be more profitable for many fanners to increase their level of cropping with the aid of fertilisers and reduce the time under pastures and still maintain high 1c els of soil fertility. This was being done very widely in Australia at the present time and the quick change in this direction had been brought about partly by the lower wool prices but also by the efforts of graiiers to recover some oTthe losses they had incurred during the severe drought of the last two years. It seemed that the same general situation applied in

New Zealand, but the New Zealand farmer was more fortunate in that he bad not had the pressure of drought to make him consider the use of more intensive land use systems.

But, regardless of whether or not it was in the individual interest of the New Zealand fanner or of the national economy to intensify cropping, it was clear that both the nation and the individual farmer should have the knowledge of how to make this transformation when the occasdemanded. Professor Crofts, when questioned about the likelihood of overseas supplies of nitrogen fertilisers becoming cheaper, said the increase in world nitrogen production over the last few years had been tremendous, but the increase in consumption had kept up with this movement. However, the large new plants that were now being constructed, based on waste products from both oil wells and oil refineries, suggested that there must be some kind of surplus during the next few years.

refining of ores. There would, therefore, be an exportable surplus from Australia for at least a limited period. “I feel that the fact that New Zealand has achieved very high yields in pastures and crops from the legumebased pastures should not stand in the way of imklnt use of this new nitrogen technology, if and when it is profitable to do co,” Professor Crofts said.

The big agricultural revolution of this age was the realisation that with fertilisers and herbicides and other agricultural chemicals it was possible to continuously crop a piece of land and at the same time increase the organic matter level of the soil in which the crop grew. This meant that while in the past Intensive cropping was generally regarded as being synonymous with soil exploitation, this need not now be the case.

Because of this, the decision as to whether a farmer should pursue an intensive cropping regime or a less Intensive one associated with pastures, was a decision which could be based on simple economic considerations and not on emotion. ' .

In the big, new plants, he said, the cost of nitrogen fixation had been reduced to a fraction of what it was 20 years ago and countries using a large quantity of this commodity, such as the United States, predicted that the “on farm” nitrogen price in 1970 would be about half that of 1965.

Professor Crofts said that Sydney University had done the first whole farm trial in the intensive use of nitrogen fertilisers in Australia in 1958. It had demonstrated it for one set of conditions—an irrigated dairy farm on whole milk supply. It had been possible to increase production by 50 per cent and lower feed costs by 75 per cent. This had been done by producing forage on the farm with water and nitrogen instead of buying in concentrates. Since 1958, he said, almost every farmer in the county of Cumberland, near Sydney, had gone into the use of nitrogen fertiliser with irrigation. Some work had also been done on the tablelands of New South Wales to increase the autumn and winter feed

It did, therefore, seem clear that regardless of whether there was a great surplus in supplies or not, the world price of nitrogen would be reduced through the lower cost of new production processes and ultimately the benefit must be pasesd on to all technically advanced nations. In Australia nitrogen production was expected to exceed demand for the next five years with the establishment of two large plants—one based on natural gas and the other on by-products of the

«, It had been possible w that winter carrying capacity had been increased fourfold by sowing four bushels of grazing oats to the acre, with nitrogen fertiliser also being used. In both of these exercises it had been necessary to make sure that the practices used had a direct relationship to the particular feed problem on the farm. There could be no generalisations in regard to the use of nitrogen fertilisers ’or Increasing animal production from fodder crops or pastures. Each case bad to be treated individually. Another example of the intensive use of nitrogen was on k'kuyu-domlnant pastures of the far northern coast of New South Wales and southern Queensland. Some dairy farmers here had been able to obtain as much as 5001 b of butterfat an aere by applying large quantities of nitrogen fertiliser with up to 2501 b of nitrogen to the acre a year. Nevertheless, in all of these instances the time of application, rate of application and time and method of utilisation of increased growth were all vital to the profitable use of nitrogen. In all cases rewards could only be reaped from the use of nitrogenous fertilisers if they were used in such a way as to secure a high return of digestible organic matter for each pound of nitrogen applied and that the forage produced was efficiently used by the grazing animal. There was no profit in producing grass or forage crops just to go to waste. 1