LUCERNE AS PASTURE BASE

Press, Volume CI, Issue 29940, 29 September 1962, Page 7

LUCERNE AS PASTURE BASE

Use of lucerne as the legume base far pastures as an alternative to. white clover is being investigated by the Lincoln substation of the Grasslands Division of the Department of Scientific and Industrial Research. At a field dajr held this week by the Halswell branch of Federated Farmers, Dr. K. F O'Connor, officer in charge of the sub-station, said that under dry land conditions with medium moisture holding characteristics, lucerne had outyielded pure white clover by two or three times and the question was whether there would be a similar advantage • with a lucerne grass sward, particularly in a summer drought. Lucerne was a slow starter in establishing, and for that reason it was choked out by ryegrass, which gave its best yield in the first year and then ran out of nitrogen in its second year. Overdrilling, he said, offered an opportunity of overcoming this obstacle by establishing the lucerne and grass at different times It also provided the opportunity for winter use of the pasture by cereal introduction to pay for the nitrogen if it was needed for grass establishment. Apart from prairie grass and short rotation ryegrass, he said, there would be no immediate response from grasses in the way of winter feed from nitrogen. Discussing trials on the property of Mr H. R. Williams in Woreleys road. Cashmere. where overdrilling of grasses into lucerne is being studied, Dr. O’Connor said that there had been fair establishment of grasses even where they had been intro-

duced into fairly grassy lucerne. Little difficulty, he said, had been experienced in getting new long rotation ryegrass established in first - year lucerne, and while as yet it had not been proved that they could be managed and the stage had not yet been reached where any recommendation could be made, it seemed that this grass would be a good companion for lucerne under Canterbury conditions. Dr. O'Connor suggested that lucerne- might initially be sown under a crop like maize, which Mr Williams had found successful, with grass and a cereal, perhaps oats, being overdrilled in the following autumn. If the oats were grazed at the right time he said that the pasture would be clear of them before the spring. Mr D J. G. Davies, an instructor in agriculture with the Department of Agriculture in Christchurch, said that with the increasing depredations of eelworms in lucerne on particularly wetter soils the introduced grass might well take the place of th lucerne as it thinned out On the property of Mr C. A. Jamieson in Junction road, Halswell. Dr. O’Connor stressed the shading effect on pasture growth under conditions of reduced light intensity in the winter so that under normal conditions clover and grass swards ceased growing in June if they were not grazed and if anything there was then a loss of dry matter by rotting through until August. On this property in trial plots short rotation ryegrass was introduced into a clover dominant sward at the end

of March along with oats and rates of nitrogen varying from nil to 1201 b to the acre. Dr. O'Connor said that plots which were in grass and clover alone had reached a peak of production by June with 8501 b of dry matter to the acre. With nitrogen they were up to 1200 to 13001 b to the acre by the end of June and remained at about that level until August Oats'and grass with nitrogen reached a peak at 1800 to 20001 b in June, a. level which would 'not have been reached without nitrogen until August "If you want to convert a clover seed sward into a good pasture you overdrill it in grass—in this case short rotation ryegrass was used. If you want Short rotation in August you use 301 b of nitrogen. If you want it by June you use 601 b. ‘ If you want maximum feed in June and early 'spring as well, you overdrill with oats and grass using 30 to 601 b of nitrogen. If you want feed only in August you overdrill with oats and grass With little or no nitrogen." Dr. O’Connor emphasised that use of nitrogen for winter feed could really only be justified where there were the mouths to eat it. Indicating that where there were winter active species in the sward, nitrogen would pay, Dr. O’Connor said that at the Grasslands substation 15001 b of extra dry matter had been obtained with 501 b of nitrogen on short rotation ryegrass. As this provided about 50 cow days of feed for the use of about 11b of nitrogen a cow day, the cost using nitrogen in the form of urea, was about 9d a cow day.

In time of reduced light intensity. Dr. O’Connor stressed the advantages of frequent defoliation or grazing to prevent undue shading —a recommendation being to keep grass at no more than shin height and greenfeed at no more than calf height. Where there was nitrogen usage he said that there was no undue suppression of clover by frequent defoliation. Dr. O'Connor’s advice was to overdrill with winter active grasses and cereals, and use nitrogen and graze frequently. “Overdrilling with short rotation ryegrass and cereals with nitrogen looks like being the way of getting over the winter trough in growth,” he said. Trials inspected during the day included some in which the Grasslands Division and Department of Agriculture and the department and Mr H. W. Mclntosh, consulting officer of the Dairy Production and Marketing Board, are associated, ■in co-opera-tion with fanners.