Role Of Drainage In Southland

Press, Volume XCIX, Issue 29401, 31 December 1960, Page 9

Role Of Drainage In Southland

Farming (By a Special Correspondent] QOUTHLANDERS listen with wry humour to the oft-quoted description of their territory by the first exploring surveyor Tuckett in 1863. Tuckett reached as far as the present site of Invercargill and reported that the mere bog was totally unfit for human habitation. Human industry, drainage, and the twentieth century technology have proved- him wrong. The background of productive wealth from farming in Invercargill’s hinterland was brought out in two recent events, the conference of the New Zealand Grassland Association in that city and the opening of Southland’s new port at Bluff. Production In the course of his paper to the conference, Mr W. Faithful, instructor in agriculture, metioned that the annual Southland wool clip is more than 50,000,000 lb —returning nearly £10,000,000 last year—and the annual throughput of lambs in the four freezing works of the province is approaching the 4,000,000 mark. Mr Faithful outlined reveral of the features of farming development that have brought about this spectacular level of production after so dismal a prospect. Drainage, especially where channel improvement and outfall drainage works have gone hand in hand with farmlands drainage practices, has given to Southland a new unsquelching landscape. The results of drainage are so seldom measured by research or experiments in the same precise way as the results of topdressing with superphosphate or nitrogen or even of irrigation, that we seldom pay any real heed to the essential character of drainage for much of our land development in the past. Under th! red tussock

sponge of the primitive Southland landscape the soil did not have sufficient strength to support even a fraction of the animal burden it is at present carrying. Soil Strength A very interesting and well illustrated paper by Mr D. B. Edmond, of Grasslands Division. Palmerston North, brought home to many at the conference the importance of soil strength in maintaining high production under pastoral use with sheep. In addition to showing how, for example, ryegrass and timothy were greatly superior to some other strains, such as Yorkshire fog, in ability to withstand winter treading at heavy stocking rates, Mr Edmond also demonstrated how damage was increased with increasing surface wetness and how the ability of soil to drain away surface water was impaired by this heavy treading under wet conditions. Failure to drain effectively where drainage was necessary eould, therefore, not only lead to lower production and some pasture deterioration. It could also lead to a more serious need for mechanical drainage. Anyone who is familiar with the hinterland of North Canterbury will know that we in Canterbury have many opportunities for development of red tussock land. Southland has given a good example. This pattern of drainage as an essential in such development was illustrated by the farm of Mr G. Fougere, at Springhills, which was visited on the field tour. On a farm of 279 acres developed with Marginal Lands loan assistance to a level of nearly four ewes to the acre, drainage costs—and the farmer still counted the job incomplete—have already totalled £2BOO. Catchment Board The contribution of the Catchment Board to drainage in Southland since 1945 did not pass without notice at the conference. The

rationalisation of drainage schemes is not a merely administrative virtue. If the Catchment Board had not taken a strong initiative in channel and outfall improvement many of the drainage improvements undertaken by farmers would not have been physically possible nor would they have been able to engender financial suppgrt for themselves. Drain age works of a major character are now extending into the difficult peat lands close to the south coast. Recreation Areas The enthusiasm with which enterprises in Southland are carried on obliges any authority concerned with land use to make decisions early or lose the chance of making any change later, With some wisdom as well as caution therefore, Mr E. J. B. Cutler of the Soil Bureau, D.5.1.R., suggested in his review of the soil resources of Southland that some at least of the peat lands and swamp lands should be retained in their more primitive condition for the use of later generations for wildlife and related recreational objectives. New Zealand is not so well endowed with resources for certain kinds of hunting and fishing tjiat it can afford to give up thoughtlessly all areas that have any potential significance to agricultural .production. Mr Cutler made some other valuable suggestions that are not unrelated to the role of dramage in land improvement on other soil types. The first of these was his classification of the best soils of the province as suitable for intensive production of grains, sugar beet and—believe it or not! —whisky as part of an intensive rotational system including grassland. The second was his emphasis on the importance of forestry and grassland management for headwaters areas to preserve the catchment of vital drainage systems, especially to guard against further lowland deterioration through shingle aggradation and flooding. (To be Continued)