Review Of Work By Institute

Press, Volume CVI, Issue 31339, 8 April 1967, Page 9

Review Of Work By Institute

“To develop techniques of revegetating eroded surfaces in the high country is a formidable task,” says the latest annual report of the Tussock Grasslands and Mountain Lands Institute in reviewing progress with the four main objects laid down for the institute when it was established in 1960.

One of the objects laid down for the institute was to develop techniques to promote a more protective and stabilising cover of vegetation, so as to mitigate soil erosion and the choking of river channels with detritus to minimise flooding and to safeguard production.

“On eroded areas above 3000 ft, climate is severe and soil fertility low.” says the report. “Technically to put a plant cover on such areas is difficult Moreover, any technique must be reasonably cheap to be practical. In the foreseeable future, New Zealand will not be able to afford to , spend vast sums to revegetate eroded surfaces merely for watershed protection. “For these reasons the institute has used in this field plants which will cover the ground quickly and which can be established from seed. A revegetotion method suitable for aerial application would be extremely valuable.

“In November, 1965, three field experiments were laid down on eroded surfaces above 3000 ft. Ten herbaceous species were tested with and without a complete fertiliser. Growth was poor without fertiliser and virtually no plants survived the 1966 winter. Plants sown with fertiliser, on the other hand, grew very well and survived the 1966 winter with very little damage from frost lift” In discussing these trials recently, the director of the institute, Dr. S. N. Adams, said that they had showed that it was soil fertility and not climate that was the factor restricting growth of vegetation in these areas.

Subsequent pot and field trials, said the annual report, had been designed to sort out the specific nutrients required to produce good growth of grasses and clovers on such eroded sites. The work had been expanded to 10 high altitude areas from Black Birch, Marlborough, to the Takitimu range, Southland.

Dr. Adams said it had been found that it was not only nitrogen and phosphorus that were deficient, but there was also a widespread magnesium deficiency, j “The persistence of the plants in the 1965 field trials through winter and their growth in the second summer is encouraging,” says the annual report. “In the long term, however, the vegetative cover may not survive without repeated and uneconomic fertiliser appUeattons unless low fertility demanding perennials take over. To see if this process can be hastened seeds of several species were

sown in the plots in the spring of last year. . . .”

At the same time the institute was interested in studying the effects of insects on revegetation of these depleted areas, as there was reason to believe that they might be playing an important rale in preventing the establishment of vegetation, and it was hoped to soon make an appointment of an entomologist to the institute’s staff, Dr. Adams said. The report notes that the first object laid down for the institute was to investigate the various aspects of management of the tussock grasslands and mountain lands.

When the institute was formed one of the first policy decisions of the committee had been to examine the present state of the tussock grasslands and this wish had been partly met by general management recording. However, this year it was decided to try to gather stock production and winter feed statistics from every back country run in the South Island. This would mean that for the first time there would be accurate data about the numbers, kinds and performance of stock in the high country, and about the wool, sheep and cattle it produced. Other information about hay, crops, topdressing and labour was also being gathered.

The 290 runs chosen for this survey Included all those generally called high country and others adjacent to them or managed in a similar way. The management officer (Mr J. G. Hughes) had completed visiting these runs for the 196546 season figures.

In elaboration of this activity, Dr. Adams said recently that the information

obtained in such surveys would be fed back to the individual' runholder, which would enable him to make a comparison between his own performance and that on a wider area of similar country and this could be the basis of attempts to improve production. It would also aid Mr Hughes in his advisory work.

The regular collection of this sort of information could also be a stimulus to runholders to keep better records. "We are sure that the results of this survey will bene-

fit the whole pastoral industry and those organisations which work in the region,” says the annual report.

It was also noted in the report that a map of pastoral runs had been prepared as a base for gathering statistical and management information from the tussock grasslands. It had won been realised, however, that it would have much wider use and interest and the initial 250 sets of the larger two-colour size map had been sold out by November. A second revised edition of this had been printed, but copies of a smaller map were still avail- | able. The report on the Walmaka- | riri catchment (undertaken iby the institute's planning officer, Mr J. A. Hayward) had been completed in October last year and it was expected that it would be published in June. “The 300 page report describes the present systems of land use, reviews the present state of scientific knowledge with regard to both pastoral production and watershed protection, assesses the potential of the region and makes recommendations regarding future land use and research.” Dr. Adams said that Mr G. A. Dunbar, the institute’s agronomist, had four fertiliser and grazing demonstration trials in the Canterbury back country. The idea behind these was that not all runholders appreciated that if oversowing and topdressing was done it was also necessary to utilise the feed grown. The aim was to establish good clover pasture on each of these 10 acre areas with oversowing and topdressing and then to maintain these with adequate stocking. The annual report says that all areas had received maintenance topdressings of 2 cwt of superphosphate to the acre in the early spring. Small trials established within each block had showed in the main that clover needed the maintenance dressing, even in one case where 4 cwt of fertiliser had been applied two years previously. The present aim was to continue these demonstrations for another season. A further objective laid down for the institute was to provide a centre to facilitate the co-ordination of all research aimed at protecting and improving the tussock grasslands and mountain lands and to make this inf ormation readily available to all interested people and organisations.

The annual report says on this point that coordination of research has proceeded through informal contacts between institute staff and research workers, and the institute with its wide contacts in the mountain lands was frequently able to put re-

search workers in touch with other scientists and with runholders to the mutual benefit of all.

The main vehicle for the distribution of information was the institute's journal “Review”. The circulation of this journal had increased by some 200 in the last 18 months, Dr. Adams said, and was now 1800.

The final object was to foster and undertake research where necessary in any appropriate fields not otherwise covered.

In tills respect the Institute had continued its policy of making research grants to outside bodies for high country research which might otherwise not be undertaken the report says. Some £1420 had been distributed during the year.

These grants had been made to Professor I. E. Coop and Mr V. R. Clark, of Lincoln College, to study the growth of weaned lambs in the high country, to Dr. G. T. Daly and Professor R. H. M. Langer, of Lincoln College, to study matagouri, to the Grasslands Division of the Department of Scientific and Industrial Research for ecological studies at the Glentanner fitid station, to Mr I. E. Owens, of the geography department of Canterbury University, to assist the Chilton valley microclimate and micro - geomorphic project, and to Drs. L D. Blair and J. G. H. White, of Lincoln College, for studies designed to extend the growth of clovers and lucerne in the South Island tussock country.

In dealing with Dr. White’s work, the repent says that a field trial on an acid soil at Mesopotamia station showed that seed inoculation increased nodulation of white clover but that pelleting gave no further gain. Without lime no lucerne became nodulated unless the seed was inoculated and pelleted. The best pelleting material waa finely divided lime.

Dr. White bad also showed at Mesopotamia that rod-seed-ing of pelleted lucerne gave much better establishment than surface broadcasting. August or early September sowings were better than October. In the field of hydrotogicti research. Dr. Adams said that Mr Hayward has started a study of the validity of runoff plots sa a measure of soil loss in eroded areas.

Mr D. McLeod, of Grassmere, Case was re-elected chairman of the management committee of the institute at its annual meeting this week.