“Ryegrass Top High Producing Pasture"

Press, Volume C, Issue 29524, 27 May 1961, Page 7

“Ryegrass Top High Producing Pasture"

It is becoming popular to criticise ryegrass, and in particular perennial ryegrass, for stock problems but Dr. P. D. Sears, director of the Grasslands Division of the Department of Sientific and Industrial Research, told the farmers’ conference at Canterbury Agricultural College last week that ryegrass was New Zealand’s No. 1 high producing pasture and people in this country would have to learn to get used to living with the pastures and practices that we nowhave. One of the main reasons that Dr. Sears put forward for the pre-eminent position of ryegrass in this country was that stock were outside all the year round. That meant that pasture species

had to be bred and selected to stand up to heavy traction. The compaction of the hooves of a cow were eight times those of a well-known, type of tractor. “The cow’s hooves are like stiletto heels of the modern woman," Dr. Sears said as an aside. Results of investigations into the effects of treading had shown quite clearly that only ryegrass, timothy and white clover could stand up to heavy traffic. That was the reason why New Zealand pastures must develop into essentially ryegrass and white clover swards. Dr. Sears indicated that the nitrogen enriched pastures of England and Holland were not without their troubles too. They had problems of magnesium deficiency and grass staggers. At the other end of the scale in the Argentine people did not believe in fertilisers. They believed that the soil that God had given them was good enough. This country was a good example for those who. wanted to get weeds into their pastures to promote stock health. “It does not really matter much when your animals are dying of foot and mouth disease,” said Dr. Sears referring to problems of foot and mouth disease and contagious abortion in this country.

Nitrogen Cycle To promote the nitrogen cycle in .New Zealand, Dr. Sears suggested that the important starting point was to select the right clover and inoculum and then the right fertiliser to get the best results out of the grass-clover combination. Dr. Sears traced the process of bringing in new country to pasture from tussock and danthonia and low scrub where stock literally died of starvation. When a start was made to develop this country by ploughing or using superphosphate, Dr. Sears said that trace element problems were encountered. Early pastures were clover dominant and there was trouble with sleepy sickness in stock. In the red clover phase there was bloat and feed flavours and estrogen problems. At this stage a lot of people turned in the fight and made silage out of the clover and ploughed the area up again to start all over again. But here the aim should be to keep stock on and as stocking intensity built up because of their ability to stand up to treading " ryegrass and white clover became dominant. From then on problems of ryegrass dominance and mainly perennial dominance showed up. These were ryegrass staggers and facial eczema and high nitrate. That could be overcome by ploughing up a bit of the high fertility pasture. The essential thing in this process was to keep sheep on in the middle part of the

programme, he said. At the grass dominant phase the pasture could be used for milk production. It was hoped that the new long rotation ryegrass would carry the pasture on further in the ryegrass dominant phase. To a questioner he said that outstanding features of it were its persistency, resistance to Argentine stem weevil and outstanding ability to stand up to summer heat in addition to increased palatability. It would also give about one and a half times the winter growth of perennial although not so much as short rotation. Hills On the hill country Dr. Sears said he regarded the fencing of the country on the basis of climatic variability as the job of prime importance. He also favoured the application of fertilisers on the weakest areas—the valleys—with stock being held there. Was not Dr. Sears running away from the goal of high production in suggesting the use of high fertility pastures for cropping, Professor A. H. Flay asked. Could there not be high production pastures and stock health simultaneously? Dr. Sears said that at the high fertility stage there was a ehance of getting a payable crop and at the same time reducing stock troubles on this country. He preferred to plough when a pasture was good enough to plough and to put stock on in the earlier stages. Professor Flay said that surely scientific investigation of hill country which could not. be ploughed was of importance for the future. Dr. Sears replied that his division was stocking six sheep to the acre on hill country. He said he preferred to put fertiliser into the valleys rather than on the tops in an effort to make best use of limited resources.

Timothy Asked about species other than ryegrass. Dr. Sears said that timothy would stand up to heavy traffic but it did not grow much in the winter. Dr. Sears said that on-e high fertility and high stocking was achieved the essential development was into ryegrass and white clover and the aim of his division was to breed a strain of ryegrass that would get over present problems. “I do not think that because you get into trouble with ryegrass you should switch straight to timothy,” said Dr. Sears. It would not carry the stock in the winter. Nevertheless the aim was to produce a timothy and cocksfoot with winter production, though no doubt there would be problems with them also when they came along. With introductions from Spain, Dr. Sears that they were seeking more winter growth in clover. The idea was to build up the clover function so that the period of clover dominance was hastened and led more quickly into the grass dominant phase.