MANAGEMENT OF PASTURES

Otago Daily Times, Issue 22328, 31 July 1934, Page 3

MANAGEMENT OF PASTURES

TOP-DRESSING IN JULY AND AUGUST HARROWING ADVISABLE NEXT MONTH Much benefit has resulted from topdressing in July and August. Hence a farmer who has not already top-dressed as extensively as is warranted may at this stage carry out top-dressing with every confidence that he will secure good results. Ordinarily superphosphate should be used almost invariably at this season; field trials have shown that in many important grass-farming districts it will make its influence felt substantially in four weeks from the date of its application at this time of the year (states the Journal of Agriculture). Under certain circumstances in July and August sulphate of ammonia or analogous nitrogenous manures may be applied with profit as a means of obtaining additional late winter and early spring feed. The use of nitrogenous manures for this purpose was discussed further in last month s notes._ Harrowing of pastures is advisable widely in August, and if not carried out on fields on which animal manure is plentiful the spring pasture growth will be very uneven, on account of the development of patches of rank herbage in the vicinity of where droppings have been undisturbed for any considerable period. As it is not at all easy to deal satisfactorily with rank patches of grass-growth on farms supporting principally "wet stock, it is desirable to obviate the appearance of such patches by timely use of the grass harrows to distribute the droppings before the bulk of their fertilising Ingredients have been washed into the soil beneath. Top-dressing of sod-bound and weedy pastures is almost certain to prove much more effective when accompanied by relatively severe harrowing. The harrowing should be severe enough to open up the turf and thereby give a chance to plants of better species, the greater growth of which is made possible by the increased fertility, to develop more vigorously, This brlrigs about the pasture-rejuvenation which is so advisable on many old-estab-lished permanent pastures that cannot be renewed economically by putting the land under the plough. FEED FOR CRITICAL PERIODS. A most important point that many farmers will need to consider at this season is the amount and location of the grassland it is advisable to put under the plough during the next few months. A prime consideration is . the adequate provision through the use of such crops as mangels, swedes, turnips, chou. moellier, lucerne, and carrots of feed for the critical periods when the feed available directly from grassland is customarily below the current requirements of stock. Secondly, the ploughing-down of many pastures is called for because of their inferior swards; often, for instance, pastures which are dominantly weeds, brown-top, or dogstai) may be found occupying ground which could profitably support swards rich in ryegrass, cocksfoot, and white clover, and this especially if given reasonable assistance in the form of phosphatic top-dressing and efficient grazing management. With past experiences in mind farmers at times hesitate to plough up pastures which they' realise are not of ag high a standard as could reasonably be expected in the circumstances; they doubt whether they will be able to replace the pastures which they consider relatively poor by one which will remain superior Jong enough to make the undertaking a profitable' one. The doubt originates almost invariably in the past use _of inferior strains of pasture species which were associated, with a rapid falling-off in the production of relatively young pastures, and to-day is unjustified because of the availability through official tion, of strains of seed the use of which will hot lead to the disappointing result* which at times occurred in the past. After making due allowance for the considerable improvement of swards that can be effected in some cases by judicious topdressing it may still be said that generally the most advisable method of obtaining an~inproved sward is by ploughing arid eventual reseeding. In some instances this method, because of labourcost or other considerations, may not be practicable, and it. may be advisable to attempt to bring about sward renovation by surface-sowing of-seed. It should be remembered that surface-sowing of seed is associated with risks, arising mainly from weather conditions,, and is not always successful. Hence, if practicable, the sowing of seeds on a cultivated seedbed should be followed. SPECIAL CARE NEEDED. Young pastures, and particularly those it is intended to make permanent, should be treated with special care during winter and early spring. The two extremes, under-grazing and over-grazing, equally should be avoided. Under-grazing is likely to occur in winter and early spring only when stock are being kept off young pas- ' tures specially to avoid " poaching" or ,"pugging" of.the soil. It leads to the ! suppression or weakening of valuable pasture species such as clovers and crested dogstail, and is likely to be particularly harmful in a young pasture which contains a large proportion of Italian ryegrass—a species which should not be allowed to become long in young pastures. To avoid both under-grazing and as much poaching as practicable, sufficient stocking should be carried out, and that as far as possible only when the land is dry. DANGER OF OVER-GRAZING. Over-grazing which readily leads to a setback to valuable species before they have properly established themselves is much more likely than under-grazing to occur in August. Over-grazing in the spring is also likely to be markedly harmful to old-established swards, especially when it is associated with under-grazing in the summer and autumn as it often is. Perennial ryegrass is especially susceptible to weakening by over-grazing in the early spring. How injudicious grazing management may influence the composition of permanent pastures was illustrated in a recent report I of an English investigation carried out :by M. G. Jones. A pasture which conI tinually had been over-grazed in the ' spring and under-grazed in the summer 1 and autumn contained approximately 2 per cent, perennial ryegrass, 6 per cent, ofk white clover, and a total of 91 per cent, of useless plants, while another portion of the same pasture after only two seasons' rational grazing and identical ! top-dressing contained approximately 21 i per cent, perennial ryegrass, 20 per cent, .white clover, and a total of 52 per cent. I of useless plants—still a poor sward, but I nevertheless substantially improved solely by better grazing management in which i over-grazing in the spring was avoided, i grazing in the spring by sheep ot ' younir pastures when not overdone is valuable because of the even, thorough consolidation of the soil which it brings about; but too-close grazing, if not guarded against, readily takes place. LUCERNE GRAZING. If possible, grazing of established lucerne during winter and early spring in particular should be avoided. Grazing by causing consolidation favours the invasion of the lucerne by ryegrass and Poa annua,'two of its worst and most common invaders over wide areas. Further, grazing keeps the growth short, which favours white clover, at times a ! serious weed in lucerne areas. HarrowI in" of established weedy lucerne occasionally may be advisable at this season, but ! generally it is inadvisable unless the conI ditions allow one to lessen substantially 1 the number or vigour of the invading weeds without unduly injuring the lucerne i itself. Especially in the main grassi farming districts, the only harrowing that I as a rule gives this result is one carried out about January or February, when i the dry conditions and the rapidity in growth of the lucerne combine to suppress weeds disturbed by cultivation. Some cultivate lucerne ns a routine measure and without due thought, and often do as much harm as good or even more—any cultivation drastic enough to thin the weeds ifc practically certain also to thin I the lucerne. Lucerne which is heavily invaded by grass should be top-dressed, not in the early spring while it is still someI what dormant, but later on, perhaps after • the first cut, when it can outgrow the ] grass. To top-dress in the early spring j would lead to relatively greater stimulation of the grass, which would intensify ■ its smothering effect—just what should ■ be avoided. GENERAL WORK.

The late July-August period is a critical one in the feeding of stock. While it may be economically sound at times to allow store cattle and sheep to fall off in condition, at this period it is often a costly matter to allow milking cows and breeding ewes to do so. In both these types

of stock production is likely to be lessened, and, in addition, ■ ravages of disease often originate from weakened vitality which arises at this stage. Yet farmers with stock unduly low in condition at this period at times cany over reserves of feed; they would probably be wiser to use such feeds as it is required and allow the future to take care of itself. , ~ . r . i During wet weather time may often be spent profitably in overhauling equipment in preparation for the busy season and in the picking over of stored potatoes. In dry weather matters to which attention often may well be given are improved farm subdivision and the construction of pits.or trenches for ensilage.