TRIALS WITH LUCERNE

Press, Volume XCV, Issue 28180, 19 January 1957, Page 9

TRIALS WITH LUCERNE

HEAVY GRAZING AT LINCOLN requirements for ESTABLISHMENT need for manuring INDICATED Because there has been a strong growth of most pasture plants this summer, attention has temporarily been diverted from the importance of lucerne as a fodder crop. Last year, under conditions of intense drought, lucerne was about the only crop that continued to make growth. At Canterbury Agricultural College, Lincoln, under the direction of Mr C. E. Iversen, senior lecturer in field husbandry, a series of trials laid down m October and November of 1955 promises to give more valuable information about this important crop. As yet the trials, which will probably be continued for about five years, are at too early a stage for concrete conclusions to be drawn, but in their establishment and the subsequent growth of lucerne on low fertility and high fertility areas, there have been some interesting developments. In one of the tria’s the standard New Zealand variety, Marlborough, is being tested for survival, productivity and season of growth against creeping lucerne or Glutinosa, a variety that has been found at Lincoln to be a good grazer, and Rhizoma. a Canadian selection with a high reputation. These varieties are being given both a severe ana a lenient grazing treatment. Mr Iversen says that farmers would normally graze their stands leniently, but if most of the grazing areas of a farm was under lucerne the plant had to be capable of standing up to harder conditions.

Some farmers are satisfied with the performance of Marlborough and do not feel that there is need to search for a better variety, but Mr Iversen feels that Glutinosa may prove superior. If, however, Marlborough can do well under conditions of severe grazing, there will be no need for a change. Heavy Grazing At intervals of about six weeks 75 adult sheep are being introduced to the l-20th of an acre plots for a period of 24 hours. This is the equivalent to 1500 sheep to the acre or four sheep to the acre for a year. Under these conditions the stands have been bared to the ground, but this week a stand of Marlborough treated in this way when it was at a height of about 27 inches was again up to almost knee level, and was rich and stronglooking after a spell of three days short of a month. To Mr Iversen, this remarkable recovery suggests that perhaps farmers do not manure their lucerne enough, and that the concentrated grazing with its application of animal manure and urine has been a factor in the revival.

This same thought has been reinforced by the experience in another trial where good responses have been obtained to the application of nitrogen and potash, though with low nitrogen potash has not appeared to have had any effect. In the trials with Marlborough, Glutinosa and Rhizoma, Mr Iversen is also using three companion grasses—cocksfoot, meadow fescue and Bromus inermis to determine their effect on the survival productivity and season of growth of the lucernes and to compare their suitability as companions for lucerne.

Ten varieties are also being tested to determine their survival and productivity under intense grazing. So far, a variety from northern France known as Du Puits is showing the tallest growth, with another French variety, Provence,, showing similar growth. Both Hunter River and a Californian breed, Caliverde, which were promising in the spring and autumn, are low looking less healthy. Hay Production Ten lucernes are also being studied for hay productivity and season of growth and in these trials Hunter River, Provence and Caliverde have fared best as early varieties. The trials are being carried out on areas both of high and low fertility and a striking result on the low fertility land has been that establishment has been very slow with plants yellowing and poor, but heavy stocking is giving promise of better results and plants treated in this way are showing much healthier growth. Mr Iversen said that when lucerne was sown a distinction had to be made between germin-

ation and establishment. Good germination could be obtained under a wide variety of conditions, but good establishment could not be achieved unless there was a good take of the inoculation. Requirements for a good take were (1) adequate moisture—one way to ensure that was to sow in a good seed bed and deep enough to see that the young plant was still able to reach the moisture—: (2) adequate nutrients to feed the host plant, including nitrogen tor the initial phase until the inoculant started to make nitrogen; and <3) adequate organic matter, which was important because of its link with moisture retention but was still more important because of the part it played in developing the inoculant.

Most of the faulty establishment was due to failure of the inoculation to take, said Mr Iversen, and one of the reasons for that could quite well be that the inoculant was faulty when purchased.

If land was fertile Mr Iversen said that it would have moisture, nitrogen, nutrients and organic matter, but if it was of low fertility, naturally or as a result of overcropping, then something had to be done to build it up or lucerne establishment would be difficult and slow. On lighter land the best way to do this was by leaving it in subterannean clover for five or six years and on heavier land through green feed crops. Two Failures On one area of land in the experimental area at Lincoln. Mr Iversen has failed twice to get lucerne established. The plants came through the ground, became yellow and disappeared. This land was under wheat for six or seven years previously, and now Mr Iversen has added to it the equivalent of 60 tons of poultry, sheep and cow manure to the acre. He is confident that this will be the answer to the past failures, where the inoculation has been unsuccessful. To pinpoint the actual reason, some of the soil has been taken to the glasshouse for further study.

Interesting results have also been observed in a trial where methods of sowing and rates of sowing have been tested. Drillings have been made at widths of seven inches and three and a half inches, and the seed has also been broadcast. The wider drillings have obviously given the best results and the broadcast plots are the worst. Seeding rates have varied from 41b and 81b to 121 b and 161 b to the acre, but Mr Iversen says that the rate does not seem to have made much difference—the plant production has been from about 21b of seed. Application of nitro lime, at the rate of two hundredweight to the acre, on the weak yellowish broadcast plants has in the space of only three weeks resulted in a transformation to green healthy plants. Trials with boron, molybdenum and magnesium have shown some evidence of a molybdenum response, but there has been no reaction with the other two trace elements.

REPORT ON WHEAT CROP According to a statement issued by the Department of Agriculture in Christchurch at the end of the week, wheat yields are expected to be satisfactory but some samples of grain will be affected by the incidence of fungus diseases. An officer said that there was probably a greater incidence of mildew than usual, which was associated in the first place with seasonal growing conditions and secondly with the fact that as the wheat acreage declined the crop was now being grown on the better class of land and the varieties being used did not react as favourably to the higher fertility. Some of the new varieties were more encouraging in that respect, he said. There was also a fair incidence of sharp eye spot, also a fungus disease. In cases of second crops on the same land the incidence of the disease was high. On some of the heavier land root rots had also occurred. In odd areas crops have been struck by hail and some damage has been severe. As is usual in a season of changeable weather, the department says that there has been a tendancy to harvest crops out of condition.

“Quite a high incidence” of diamond back moth has been reported in feed crops of rape. The incidence of aphis is lower than it was last year, but it is still making its presence felt in some crops on dry land which are now ready to feed. More particularly in South Canterbury and North Canterbury, springtails have been responsible for some damage in crops in the seedling strike stage, but the department states that it is safe to say that on an average crops are better than normal.