PASTURE YIELDS

Hawke's Bay Herald-Tribune, Issue 34, 24 February 1937, Page 15

PASTURE YIELDS

Autumn Work On H.B. Farms MANURING & HARR0W1NG An outstanding exainple of the value of top-dressingj in relation to pasture production was afforded by an inveetigation made in connection with th& inquiry made kome tinle ago by the New Zealand Dairy Oommissidn. A study of the actual iresulta of . some 560 farms on the North islahd showed tHat on those farms, Whete the production of butterfat was less than 75 lb. per acfe, the expenditute in ferfilisrs ateraged 5/8 per acre, and the cost pf fertiliset per lb. of butterfat was l.l£3d. On those farms whefe the butterfat pro^ duction ranged between 125 and 150 lb. an acre, the average expenditiire on fertiliser^ was' 10/9 per acre, and the cost of fertiliser per lb. df butterfat was 0,943d. Where the production of butterfat ranged from 200 to 225 lb. an acre, the average ecgpenditure on fertilisers was 14/8 pier aCre, and the cost of fertiliser was 0.839d. On those farms whefe butterfat production ex ceeded 250 lb. per acre, ihe average expenditure on fertilisers was 18/10 an acre and the cost of fertiliser per lb. of butterfat was 0.803d. '

Production inerea&d. This survey thus disclosed that liberal use of fertiliser was associated with substantially increased ' production and de'creased overhead in respect to the cost of producing each pound of butterfat. Further exataination of the figures shows that the overhead for fertiliser waa 48 per ce'nt. higher with iight use of fertiliser thah with the relatively heavy dressings. TheBe figures, as Well as the experience of hundreds of farmers here in jHawke'a BAy illustrate clearly the fict that, eveia in times of low prices, it pays to top-dress liberally. This heing the case, it should be obvidtis that, with higher prices for farin ptoduce, liberal top-dressing will be eVen mofe profitablo. DiscontinUance of top-dressing, on the other hand, though no't hbbessariSy associated with an immediht« fajling off in production, will certainly be aBsociated with an immediate commencement oi deterioration ih th© quality and vigour of the pastures. Normally, this dfeteridration will be gradual at the outset. because of the residual effect of previous manurial dressings, and it is because of this gridual hature of the decline that, it mfty escape notjoe for a iime. Eveqtqa^y, hdwever, the deterioration will be» obvious, since it will be acpompanied by a marked change in the character of the herbage— undesirable plants and weecis increasing) in propiinence at the expense of the rye grass, cocksfoot, clov-i ers and other more desirable elemepts that made up the original pasture. Alraost without exception the first need to be met in rOstoring the de« pleted fertility pf pasture land is to strengthen the supply of availabie phosphptes. In regi'ons of only medium rainfall sueh as Hawke's Bay, Super. phosphate is the only fertilieqr likely to give appreciqble results, and, even in regions of moderate to high rain, fall, it is the most aatisfActory and profitable fertiliser to apply. $uperphosphate brings about additional growtb more quickly than any other fertiliser, and, except in isolated instances, the duration of its itifluence is greater than is the case with other ferilisers. f Super and SourneSe. Contrary to a belief still held by •some farmers, superpbosphafe doea not cause aiiy increase in the sourness of the soil, and extensive field experience here anjl in other countries has shown that, normlally, repeated use of superphosphate on the same land is associated with increased fertility, which is reflected in improved appearihce and production of the pastures. The fertiliser may be applifed at • any part of the yefiir, but maxiraum behefits usually follow top-dressing carried out . early in the autumn, as eoon as weather conditions are fayourable to %jjpsture growth. The optimum application varies with soil and climaijc conditions, but in iew cases should the dressing be less than 1 cwt. per acre, and where heavier dressings huve been shown to b© profitable, a dressing of at least 2 cwt. pCr acro is adVocated. In some cases, especially where there is a prospect of a shortage of winter feed, it may prove profitable. to apply in late Mhrch or April a soluble mtrogenous fertiliser such as sulphate of ammonia, wbich should be put on at the ratp of about 1 cwt. per acre. As a genefal rule, howovei, tests have not shown any very profitable results from tbo use of nitrogenous manures. It has .been shown that ammonium sulphate generally gives a sharp stifnulus to the growth of tho pasture for a short period aftfer application, but thi6 niay be foltowed by a comparatively long jperjod of depreSSioh. . Sulpllate of anlmonia should not be applied alone. To obtain the maximum results the nitrogenous manpre should be used with supetphosphate, applied at thr same time or shortly before. Again, it has been noted that the fullest benefit from the use of sluphate of ammo- | nia is associated with rece'ht liming, j nnd from its Use on vi'guftras, welldrained pastures in which rye grass is prominent. Apart from top-dressirig, tbe early "itumn should be the occlision for a '• ugh Tiarro\7ing of the pastures, ;.■> o' jective bein'g the breaking up

and even distribjition of th© animal drpppings. Suitably broken up and scattered, tbese drcppings have a cohsiderable fertilisittg value, but if left itndisturbed they bring about deterioration rdther than improvement of the sward. The practices recommended above apply with particular force to young pastures, which may deteriorate rapidly if sown on soil lacking in fertility, It is siir.pler and more profitable to prevent sueii deterioration by 'liberal top-dres^ir)g in g(ood tiipe rather than to attempt later on to renew or restore the deteriorated sward-