SEASONAL NOTES.

New Zealand Journal of Agriculture, Volume 54, Issue 3, 20 March 1937, Page 176

SEASONAL NOTES.

THE FARM.

Autumn Management of Grassland.

Because exceptionally bountiful rains have been very widespread this summer, coarse mature woody herbage has been carried over much more extensively than usual from the summer period of heavy production. As a rule such coarse growth should be removed in the autumn : it delays the development of the fresh leafy condition which in the autumn characterizes pastures that have been well grazed throughout the year.. If it is not practicable to employ store stock in the removal of the tall coarse growth, then it is likely to be advisable to remove it by “ topping ” with the mower. Apart altogether from the tall coarse growth of the pastures species, topping of pastures may be valuable to remove the aerial, portions of shade-creating, weeds such as docks, spear thistles, and willowweed. If weeds of this type are not removed they tend to weaken greatly the pasture-plants in their immediate vicinity and to create vacant patcheson which inferior plants later become established. When they are mown, however, they cease to create the shade which is harmful to .valuable-pasture-plants.

Autumn harrowing of pastures is a valuable practice which widely may be carried out advantageously in March on dairy-farms. A main benefit, of such harrowing is the distribution of animal droppings which, when; suitably scattered, are of considerable fertilizing value, but which, if not scattered, tend to bring about deterioration instead of improvement of thepastures and to increase the difficulty of carrying out fully efficient grazing.. The thorough distribution of droppings that is desirable usually necessitatestwo harrowings ; one harrowing. at right angles to the other is moreserviceable than two harrowings in the same direction around the field.

Top-dressing.

Many could profitably spend more on top-dressing of grassland than they are spending. Grassland of low productivity may often be madeof high carrying-capacity by adequate use of fertilizers, provided the management is made appropriate to the changed character of the sward. In such cases the main questions the farmer has to decide relate primarily to additional stocking.

Firstly, before launching out on an increased top-dressing programme the farmer must be assured either that he can finance the purchase of the additional stock needed to cope advantageously with the increased production of feed or that he can otherwise dispose profitably of the feed by hay-making, by selling, grazing, &c. The crux of the position is that understocking may result not only in waste, but also in pasture-deterioration and in other undesirable effects. This has been well exemplified in the current producing season when the increased production of feed that hasbrought about understocking has been due not to top-dressing, but to the unusual abundance of moisture.

Possibly there has been too much tendency to consider top-dressing' as a means to increased production : top-dressing certainly has caused much of the increase in our farm production during recent times ; but on thousands of farms it now is the essential, measure in avoiding decreased production. Hence a farmer who does not seek to increase his production may, nevertheless, need to top-dress more freely than he plans. The residual influence of previous top-dressing is particularly likely to mislead

farmers to the unfortunate conclusion that their . grassland, is not being affected detrimentally by discontinuance of top-dressing. Instances have come under notice where farmers who have regularly been applying libers 1 dressings of superphosphate or other phosphates have discontinued topdressing for a season ; and for that season the carrying-capacity has not always been affected appreciably. But the immediate effect on the carryingcapacity is not likely to indicate the ultimate effect of not top-dressing grassland the productivity of which has been built up even partially by earlier top-dressing. This earlier top-dressing normally, under New Zealand practice in which phosphates dominate, creates reserves of' fertility which represent part of the current capital value of the farm and management which does not provide for the maintenance of these reserves, simply involves living not upon income wholly but upon capital to some extent at least.

The opinion has been voiced in public authoritatively that about half our total production of butterfat may be attributed to an annual outlay of about £2,000, 000 on fertilizers for top-dressing. As the value of the butterfat now produced annually approximates /20,000,000 (with butterfat at is. a lb.) it is clear that the dairying of the Dominion is receiving a handsome gross return for its outlay on top-dressinga gross return which assuredly leaves an attractive net profit. When only a portion of a farm is to be top-dressed it is, as a rule, advisable to select two types of fields for treatment. In the first place a special endeavour should be made to top-dress newly established pastures : it is likely to be more profitable in the long run to prevent, by suitable topdressing, early deterioration of young permanent pastures than later .on to renew or repair them when deteriorated. Secondly, and ' apart from young pastures, when only a portion of a ' farm is to be treated it is advisable as a rule to top-dress the fields supporting the better swards ; then the effect of the fertilizer is exerted on a greater proportion of the better pasture-plants, which have a greater capacity of responding usefully to improved fertility than have the inferior plants or weeds which are more common in the poorer swards. For instance, more is accomplished by stimulating the growth of rye-grass or of cocksfoot than by stimulating -that of brown-top or of rib-grass. Despite the fact that there is widespread scope for profitable extension of the area top-dressed, it needs to be kept in mind that top-dressing is not always and necessarily economic. In short there are grassland areas on which top-dressing cannot be recommended. This is true chiefly of land of relatively low carrying-capacity, and especially is this so when low prices prevail for the produce of that land. The converse of this is provided in the fact that the recently improved prices of wool and sheep hasmade top-dressing profitable on sheep-country where previously it was unprofitable. The position probably may be summed up in a manner useful for practical guidance by saying that the area on which top-dressing is not profitable at ruling' market prices and on which “ wet ” stock are carried are exceptional, and a farmer should be sure his is one of these exceptional areas before he eliminates the-assistance of suitable top-dressing from his farming. Further, the potentialities of profit from top-dressing can be realized properly only when the top-dressing is judicious and available evidence points .to the. conclusion that at times top-dressing is far from judicious. Injudicious top-dressing arises in two main ways : sometimes funds are dissipated on top-dressing material from which little or no visible benefit has been noted, , whereas often the funds could have been devoted to the purchase of other material which is known to' give eminently economic results ; sometimes the potential ' benefit . from one fertilizing-material which is used is wholly or partially lost unless another material is used also, and in .practice this second material is omitted. In liming the two

phases of injudicious top-dressing are exemplified ; sometimes lime is applied when there is no evidence that it is profitable to use lime, and sometimes lime is not used when phosphate is used and when that phosphate gives a poorer return than it would give in association with lime. The position in regard to potassic fertilizers is roughly similar to that in regard to lime. ' ' For some years.a survey of the response of grassland to these fertilizers has been progress and information regarding the response in specific areas is obtainable from local officers of the Fields Division. In general, the first objective in top-dressing should be to increase the supply in the soil of phosphate available to the crop. The results in the field well justify the very general use of superphosphate, relative to which there are two facts which still seem not to be generally known : superphosphate does not cause any permanent increase in soil-acidity, . and superphosphate is far from fleeting in its influence. Over wide areas of . fairly heavy rainfall basic slag is known to give uniformly good results, and in districts of good rainfall African and similar phosphates may be expected to prove satisfactory. Because of the variable visible results from district to district of both lime and potash it is really futile to make any general statements regarding them : the best course for those desiring guidance about them is to seek information from local officers of the Fields Division.' Wheat-growing. In the main South Island wheat-growing districts spring-sowing should be carried out only when circumstances necessitate —autumn and early winter are the ideal sowing-times. In the most southerly., wheat areas and in the North Island spring is usually the most advisable sowing-season. Hunter’s, Pearl, and Velvet definitely should be sown in the autumn or early winter. Solid-straw Tuscan may be sown both in the spring and in the autumn or early winter. Wheat needs, a fine but firm seed-bed. The advisability of firmness often makes it possible to grow wheat successfully without ploughing after peas or potatoes, the sowing of the wheat being preceded simply by two or three diskings. It is not desirable to work the surface soil down to a very fine condition, for fine particles have a tendency to “ cake ” at the surface, whereas small lumps break down gradually into a desirable fine loose surface, and in their early stages provide some shelter for the seedlings. When wheat is to follow grass or clover, skim-ploughing should have been done before these notes are published, and, if not, it should be treated as urgent work. About six weeks after the skim-ploughing, the surface should be disked to obtain a fine condition, and then ploughing to a depth of 6 in. should be carried out. When wheat is to follow oats or wheat the stubble should be first disked or grubbed, and, to obtain a fine tilth, should later be ploughed to a depth of about 6 in. When wheat follows grass or a cereal crop there, is always danger of infestation by the grass-grub. Extensive trials carried out over a series of years have shown that over a wide range of country quite a good profit results from the use with wheat of i cwt', of superphosphate to the acre, and the bulk of the wheat sown for some years with satisfactory results has been manured accordingly.

Measures of distinct value in controlling certain serious diseases of wheat should be made a routine feature of our wheat-growing. Further, these measures should be carried out properly, for, if they are not so carried out, they are likely to be ineffective, • or, alternatively, at times to cause injury to the seed. The present trend in the treatment of seed-wheat is to replace wet pickles, usually solutions of blue-stone or formalin, by various substances used as dusts. . Advantages of dusts are the absence of danger of injury to the ; seeds and the convenience due to the fact that dusted seeds keep well without damage, so that dusting may be . carried out at any

convenient time instead of being restricted to the busy time of sowing. Full information about the effective dusting of the seed of wheat and of other cereal crops is obtainable from officers of the Fields Division. The treatments of seed of oats and barley is just as advisable as is that of seedwheat, unless it is quite definite that the crop is being grown only for green feed. ' . : . . . - . General Work with Crops. Oats for winter and spring feed and subsequent grain-production should be sown not later than April or early May. Generally they respond profitably to the use of i cwt. to 2 cwt. an acre of phosphatic manure in which superphosphate is the dominant ingredient. The proved kinds of Gartons may be looked upon as the best all-round oats for the South Island. Gartons does not stand feeding-off to the same extent as Algerians, and should be fed-off once only and that feeding-off should be done quickly. Algerians, which are best when autumn-sown, are much used, with success, for green feed : they can be fed-off both in autumn and spring, and provide good chaff. Quite often maize and millet grown for green feed suffer damage from autumn frosts. To avoid such damage these crops should be utilized during April, and preferably in the first half of the month. ■ When .abundance of other feed makes unnecessary the feeding to stock of these crops in a green condition, as is likely to be the position often this year, 'then they should be conserved preferably as silage. Swedes which have suffered a serious attack of dry-rot-should be fed off without unnecessary delay if they can be utilized to advantage. Sometimes' after the last' cut of the season lucerne is grazed, and, in consequence of the trampling of the stock, the land is consolidated. The consolidation favours the invasion of the lucerne by weeds, including grass and clover. When it is desired to maintain the stand of lucerne as pure as possible, then late-season grazing of it is clearly inadvisable: it is especially so in districts of good rainfall in which weed-invasion is one of the worst troubles in lucerne-growing. .

—R. P. Connell,

Fields Division, Palmerston North.