Systematic Pasture Grazing

Timaru Herald, Volume CXXXVII, Issue 19668, 9 December 1933, Page 15

Systematic Pasture Grazing

QUESTION OF LENGTH OF REST

In recent years many farmers hav increased the production of their grass land by adopting a system of higl manuring in conjunction with the ro tational grazing of their pastures. Th advantages of rotational grazing hav long been recognised, but during th past few years there has been a cer tain amount of doubt as to the lengtl of rest a pasture should have betweei each grazing. It has been shown that young gras; is more nutritious than older grass but experiments have indicated tha pastures grazed often give less tota bulk than pastures that have beet rested for long periods. It is of im portance, therefore, to decide what fre quency of grazing will give the bes animal production, or, in other words how long pastures can be allowed t< grow’ before they deteriorate in qual ity. The same question, in anothe fbrm, is: How often can a pasture to grazed without seriously reducing thi total bulk of herbage produced? Reliable Guidance. This point has been the subject o investigation at the Welsh Plan Breeding Station during the last fe\ years and sufficient information ha accrued to give reliable guidance in th< matter. Trials were commenced h 1928 on a sward consisting of severa mixtures of grasses and clovers, th' grazing being so arranged that thi sheep used had equal access to all thi mixtures under each scheme of graz ing. The area used was divided inti three strips, each of which w’as sub divided into five plots. The threi strips were treated exactly alike, ex cept that each plot on traverse A hac four weeks’ rest between success!vi grazings; those on traverse B had tw< weeks’ rest, and those on traverse C had only four days’ rest. The live-weight increase of the sheet on the three pastures for the fou: years during which the experiment wa, conducted has indicated a distinct ad vantage from a policy of long spelling The “two-week-rest” pasture gavi 95.5 per cent., and the “four-day-rest' pasture only 83.2 per cent, of the live weight increase produced on the “four week-rest” pasture. Expressed ii terms of pounds per acre, the “four week-rest” plots produced 491 b. mori increase in live-weight than the “two w’eek-rest” plots, and 1861 b. more thai the “four-day-rest” plots. With re gard to the number of sheep grazinj days provided by the three pastures fo: the four years, the “four-week-rest' pasture again did better than either o the other tw’o. The “two-week-rest 1 pasture produced 91.9 per cent, and thi •four-day-rest” pasture 88.6 per cent ol the number of sheep grazing day: given by the "four-week-rest” pasture Subsequent Effects. The data collected during the trial nave shown that the management o the pasture in any one year affect; its growth in the year. The plot: which were rested for tour weeks between grazing gave, on an average 1431 b. more spring growth than thosi which had two weeks’ rest and 3311 b more than those which had only fou: days’ rest. This corresponded to i decrease of 11 per cent and 5 per cent respectively. Decreases in yield resulting trom tex frequent grazing have bedn shown t( be different for various species. Th< yield of cocksfoot was reduced by 4 j>cr cent, on the “two-week-rest” pas ture and by 78 per cent, on the 'four day-rest” pasture, compared with It. yield on the “four-week-rest” pasture This decrease was far more marked ir cocksfoot than in tin* total herbage. * that It is considered that some specie must react either differently, or to i

different degree, compared with other species. It has been apparent, also, that even different strains of the same species react to a different degreeGrowth of Cocksfoot. The spring growth of indigenous cocksfoot was reduced by 43 per cent, on the “two-week-rest” plots and by plots, while that of cocksfoot was re--76 per cent, on the “four-day rest” duced by 67 per cent, and 80 per cent, respectively compared with their yields on the “four-week-rest” plots. The data collected has shown that cocksfoot does not thrive on areas which are grazed often, but that it does relatively well on areas receiving four weeks’ rest between successive grazings. The most striking feature of the effect of grazing management on the various species has been the indication that cocksfoot is the only one present in any quantity in the sward which has shown fewer tillers on the frequently-grazed pasture. This decrease, revealed by an examination of the sward in September of last year, has been very marked, the “two-week-rest” pasture having 43 per cent, and

the “four-day-rest” pasture having only 32 per cent, of the number of tillers present on the "four-week-rest” pasture. Yorkshire fog and bent and crested dogstail have shown a tendency to an increase in the number of tillers on the areas receiving the short rest periods. Wild white clover, miscellaneous weeds and rough-stalked meadow grass have all shown a far greater increase in the number of tillers on the areas receiving the shorter periods, of rest between successive grazings. Taking all species into account, it has been shown that the “two-week-rest” pasture gave 5 per cent, more and the “four-day-rest” pasture 17 per cent, more tillers than the "four-week-rest” pasture.