Grassland Development On Hills Or Plains?

Press, Volume XCIX, Issue 29366, 19 November 1960, Page 9

Grassland Development On Hills Or Plains?

[By a Special Correspondent] r £'HE first meeting of the New Zealand Grassland Association which I had the good fortune to attend was in Invercargill about 12 years ago. The then Mr Bruce Levy had some stringent comments to make on the productivity and composition of developed pastures in Southland and his personality and vigour are still held in some awe even if the exact nature of his strictures is forgotten. Sir Bruce Levy would probably be a more contented visitor to the Great Southland Plain in 1960 for Southland fanners have not been idle.

I left Southland after that first conference and travelled north through the desolation of scrub and red tussock, dodging rabbits all the way from Mossburn through Parawa to Kingston, and on up to Central Otago with the air sodden with the stench of those pests over the tussock grasslands, where only the contrary or hopeful ones among us would think that grassland agriculture as we know it could have any significance.

Change Time passes and with it the fixed prejudices and the fixed landscapes those prejudices generate. Southland plains farmers now believe* in ryegrass and white clover, although they have a soft spot for timothy. The long-standing concubinage of wax matches and a swamp plough is giving way to the more legitimate union of oversown clover, rhizobia bacteria and superphosphate in lower altitude tussock grassland development. Tussock grasslands in Southland were, in many respects, later in receiving the impact of modern scientific experiment, but once started. .Southland,'in this as in so many other respects, is like a mob of startled run cattle —soon in full gallop and hard to head. Mr George Watt, who is shortly to become Commissioner of Crown Lands in Canterbury, in his own very capable and realistics fashion took a conservative look at current trends in land development in his address to the conference. Over the next 20 years he foresaw an increase in sheep numbers from 5.75 m to 8.45 m, an annual average Increase

of 3.35 per cent He estimated that there would be an increase of about 50 per cent in total wool production, lamb killings and prime beef production. At current prices these production increases would represent a steady march in the level of total incomes from £2lm in 1960 to £ 31.3 m in 1960, without making any allowance for increased agricultural returns. Mr Watt considered the role that each class of country would have in this production increase. For example he reckoned that the already developed land of 1.3 m acres of grass at present carrying just over 5m sheep could be expected to be carrying nearly 6.5 m sheep and additional beef cattle by 1980. On the partially developed land comprising 644,500 acres, and including 166.500. acres being developed by the Crown, there was expected to be an increase of about 1.25 m sheep over the next 20 years reaching a total of 1.6 m for 340,000 acres in grass. Pastoral land totalling nearly the same area as the already developed land was, however, more conservatively appraised. Here Mr Watt foresaw an increase in stock numbers of about 25 per cent, for sheep and about 70 per cent, fbr cattle to a total population of about 0.5 m sheep equivalents.

Mr Watt drew attention to some features of this pastoral land which suggest a reason for his more conservative but still optimistic approach. About C 3 per cent of it is above the 3000 ft contour. At present levels of knowledge this high land does not have much prospect of successful use for pastoral purposes in the mind of many authorities. The area of hilly country between 1500 and 3000 ft contours totalis about 400.000 acres. Mr Watt pointed that although about 1000 tons of superphosphate are being applied to the pastoral lands annually very little of this is being put on above 1500 ft. This, neglected zone between 1500 and 3000 ft was cited by another speaker at the conference, Mr W. O. Sly. soil conservator in Invercargill, as that offering best prospects for improvement. The use of sulphurised super with aerial sowings of clovers, cocksfoot and tall oatgrass had given spectacular results in the Mid Dome soil conservation reserve. Not only had severely depleted slopes up to 2500 ft been stabilised by the fibrous rooting habit, especially of tall oatgrass, but there had been luxuriant growth on hitherto iO acres to the sheep country so that its present prospect was equivalent to cne sheep to the acre.

Some outstanding results were also shown in the paper presented by Mr T. E. Ludecke. scientific officer of the Department of Agriculture, Alexandra, working at Mount Benger on the sehist mountains similar to the mountains of north-eastern Southland. With oversowing and regular topdressing the intertussock pastures on his trial areas were producing 45001 b dry matter to the acre, equivalent to a sheep to the acre or more if management was adequate for efficient conversion. Rather striking was the observation made by Mr Ludecke that the rate at pasture growth during spring and early summer at 2000 ft on the mountain slopes was equal to that of well irrigated trial areas in Central Otago. With some humour Mr Ludecke suggested that his audience beer in mind the great difference in cost between developing an acre of fescue tussock country and developing an acre of borderdyked irrigated pasture. Requirements A particularly attractive feature of Mr Ludecke’s paper was the way he related the relative needs of phosphate and sulphur to the different classes of country described by different soil types The younger or less leached soils on the fans and hills were shown to need less phosphate than the older soils on fairly level ground where leaching had been at work over the years. Mr E. J. B. Cutler, of the Soil Bureau of the D.5.1.R., who gave an account of the soils of Southland to open the conference, might well have given the closing word to this subject It seems that .where we may gain, or think we gain, by being able to tear up land with giant discs or swamp ploughs, may have to be paid for by extra manure and lime. No doubt this extra cost had been .paid in Southland and has been well and truly repaid, but the way the aeroplane is tackling hill country where fertility problems are not so severe is a lesson that will not be lost on Southlanders. Tire monopoly of the big tractors on land development has been broken and other provinces may well look to their laurels where hill country improvement is involved. (To be Continued.)