OUR NATURAL PASTURES.

Dominion, Volume 3, Issue 857, 1 July 1910, Page 10

OUR NATURAL PASTURES.

TUSSOCK-BURNING CONDEMNED. In both tho North and the South Island there are great tracts of nal'ural pasture: .In tho first number of the ■"Journal of the Department of Agri-. culture," Mr. A. H. Cockayne, Government Biologist, has an article on the ."Effects of Burning on Tussock. Country." He says that it is estimated of tho 21,000,UU0 acres undei occupation in the districts of Marlborough, Canterbury, and Utago, 15,000,000 acres (about 71 per cent.) consists oi more or less native grasses. On all the stations above liOOOft. thero are "summer country" and "winter country." On account of its being under snow tho. former can be used only ■in summer: the latter is grazed during <the greater part of thu year. Dealing with. tjio effects of burning Mr. Cockayne tfeats particularly of tho effects on winter country, as thu results'are not so marke'd on summer country. "Spring burns,"., he says,. "cause tho . desti'uction of-all-the accumulated dead material of the tussocks, that, are .acting as soil-mulch, • amT tbo slumps that are left do not form any shelter for the .■numerous feeding plants that are growing in and around litem. Alter burning, the tussocks rapidly shoot up again, bnt their vitality is much impaired, and the struggle' between them and the unfavourable conditions of heavy wiivt and drought becomes much more severe. Tho strain that has been put upon them in laving to dovelop rapidly, a-new growth of leaves uses up all the reserve luoit 'they may havo , accumulated;; . Consequently, they, stop growing much earlier in tho year than if they had not been burnt over, and, although appaiently yielding for a' fen- weeks, a more abundant supply of eatable herbage, they do not x'rouuee'the amount that is normally formed by an unburnt tussock. With regard to : the blue-gross, - tho most important feeding-constituent of the pasture, the young herbage that is formeld after burning is greedily devoured by sheep, and in many cases the plants are eaten right out and killed. Such a. condition would not occur on an unburnt pasture, and, although the yield for any particular season would be. less, there ■would be a succession of feed spread over a number of years; also, the plants would remain undamaged, and, if not stocked too heavily, would increase rajthcr than diminish. "Summer burns are by far the most destruction nt all, us they actually kill out vast numbers of tussocks, and even where their effect' is not so disastrous! they almost completely prohibit the production of any seed. Besides the actual destruction of much of tho vegetation and the accompanying humus content of the soil, summer burns caus« whatever vegetation is left to bo exposed to mauj unfavourable conditions for regeneration —conditions that won,VI have had but little effect had the pastures been allowed to remain in a stable condition. ;Tho burns occurring in late summer and fftuturnrt ore especially injurious, in- that they destroy the majority of tho seed that has either fallen to the ground or been blown into the centre of tho tussock masses. To recapitulate: The spring burns lessen 'the general. vitality of the pasture as a whole, and render it less able to withstand unfavourable climatic conditions. The summer burns actually till out the tussock, and hasten on the work of idepletion.- The autumn burns render tho process of regeneration an impossibility by' destroying both; the seed, and the most favourable medium in which it eun develop." After stating and controverting the reaions generally adduced as to why burning should be clone, Mr. Cockayne proceeds to show where burning is permissible. He says: "Under certain conditions burning is an essential feature in the management of natural pasturages; but whenever it is done the object should bt to attempt to destroy some special undesirable element of the vegetation that by its spread or tsupei abundance exerts an injurious effect on the ground for feeding purposes. Thus, in localities that are being overrun by bracken (Pteris aquilina), burning is often necessary, and ehonld bo followed by surface sowing with grasses that aro liable to hold their own against the fern when it reappears. Again, in many localities whore mnnuka is becoming the dominant plant, burning is essential in checking it from turning 'pasture-land into scrub. In certain positions, especially in damp soil, where the silver tussock by its rank growth is smothering out the finer grasses, an occasional burn is of value; but such localities are generally suitable for the growth of a better crop than tho natural one, and the effect of surface-sowing with European grasses will often turn such land into meadow. Tn all these cases, it will be noted that the object of burning is not to directly improve tho feed-ing-value of tho natural vegetation, but to actually alter its composition—to produce n. new typo of vegetation better fitted for the purpose required, exactly in th# same way as forest is often turned into grazinß-land by artificial means."

The Tnrannki Executive of tlifl Farnwrs' Union has deferred 'consideration of the following resolution, which was adopted by tlio conference: —"That in conjunction with tho beating of dairy stock lor stud purposes a Stud Book be kept and stock eligibl® to be placed ill tho Herd liouk shall be: (1) Cows giving not less Hum 3001b. butter-fat for the season; (2) bulls whose dam and gTand-dam on the siro's side havo producod 3001b, butter-frit for the season." A cow which gives 3001b. of butter-fat is about £15 cow, and probablT the only matter of discussion, when tne subject is brought on again, will bo whether that is a high, a low, or a lair demand.