PASTURE SEEDING RATE STUDIES DISCUSSED

Press, Volume XCVIII, Issue 28832, 28 February 1959, Page 9

PASTURE SEEDING RATE STUDIES DISCUSSED

On the basis of trials carried out at the Department of Agriculture’s research station at Invermay in the 1956-57 and 1957-58 seasons on fertile, plain’s soil and less fertile hill soils using pasture mixtures containing varying rates of perennial ryegrass and short rotation ryegrass with constant rates of cocksfoot, timothy, white clover and Montgomery red clover, Mr N. A. Cullen, a research officer at the station, told the last New Zealand Grassland Association that it was obvious that the use of high seeding rates of ryegrass, could result in severe suppression of slower establishing species, particularly cocksfoot timothy and white clover. Red clover was less sensitive to competition and was not affected to the same degree. With lighter ryegrass rates this competition was less intense and as a result sward composition was likely to be superior while production, except for the. initial phase, was comparable.. In the trials the rates of perennial ryegrass varied from 0 to 201 b an acre in the first year and from! 0 -to 151 b in the next, with the! short rotation ranging from 0 to151b in each series and the cocksfoot in each trial was 51b, timothy 31b, white clover 31b and Montgomery red clover 31b. Two Advantages Mr Cullen said that a high seeding rate had two main advantages. That was to suppress weeds and give quick initial ground coverage and consequent higher production at that time. Where these factors were of cortsiderable importance, such as on weedy soils and in marginal land development, the heavier, seed mixtures should be sown.

Under most conditions pastures in Otago and Southland were sown in the spring and early summer. At this time there was usually adequate feed available for grazing and hence the profuse growth resulting from a high seed sowing could be an embarrassment and be inadequately controlled as a result. For this reason lighter seed rates, were'.little disadvantage at this time. By the spring following sowing when maximum production was desirable .the initial advantage from the high rates would have Been largely lost and the lighter mixtures were likely to be comparable in yield and superior in composition. In the long term light seed rates

had many advantages, particularly In regard to composition. The violent change from complete ryegrass dominance to complete clover dominance was largely avoided and seasonal growth was more even, Summer growth, in particular, was usually higher and this might be of advantage where lamb fattening was Important These trials had been sown without a cover crop. Where rape was included tne effects and results were likely to be different as the lighter seed rates mixture could suffer severely from the rape competition.

Mixtures including short rota--tion ryegrass had the important advantage of relatively high production in the winter and early spring and for this reason short rotation ryegrass was worthy of inclusion. However, it was apparent from the results of these trials that the amount of short rotation should be kept to a minimum so that the suppression effects were comparatively small. In the trials the amount of cocksfoot, timothy and clover sown had been constant. Other ‘work indicated that increasing the ! rate of seed of these species would not compensate for the suppression effects of the high ryegrass seed rates. In the discussion which followed, the presentation of Mr Cullen’s paper, successes with sowing rates much lower than those mentioned by the research officer, were quoted, but Mr L. W. Blackmore, an instructor with the Department of Agrii culture at Dannevirke, warned that there had been cases where farmers had been advised to reduce their sowing rates with unsuccessful results. Poor cultivation, lack of consolidation and poor techniques of sowing had existed. He felt that the work at Invermay had been done under ideal conditions and some degree of caution should be exercised In applying it to general farm practice.

Lucerne And Grass

Lucerne is not a strong competitor with other plants but it can be grown in combination with a palatable grass, provided the rate of sowing of the companion grass is kept to a minimum and the stand is managed to keep the grass from dominating the lucerne. With the more aggressive grasses this can be achieved best by hard winter grazing. Becent work by the Department of Agriculture indicates that this winter grazing should be undertaken during early winter—up to mid June —if the subsequent spring growth of the lucerne is not to be affected. The grasses most commonly included are cocksfoot, Phalaris tuberosa, timothy and prairie grass.

What We Eat

“In a recent publication it was reported that an American reaching the age of 70 has consumed during his lifetime 150 cattle. 225 lambs, 20 , sheep, 310 pigs, 2400 chickens, 26 acres of grain and 50 acres of fruit and vegetables,” said Dr. Peter Sears, Director of the Grasslands Division of the Department of Scientific and Industrial Research, in a recent address. "If we add milk, cheese and butter to this, and make adjustments between chicken and lamb and also of course add an appropriate acreage for barley to cover essential beverages, we would undoubtedly get a similar set of figures for New Zealand or any other country enjoying high living standards. Compare this with low acreages of rice, wheat, or millet and the fish diets of people on low living standards and we can readily see the gap available for filling by New Zealand produce. . .