GRASSLAND CONFERENCE

Grey River Argus, 12 August 1937, Page 11

GRASSLAND CONFERENCE

o- I Presidential Address DUNEDIN, July 10. The overwhelming importance of grassland in the National economy of New Zealand was emphasised by Mr. A. H. Cockayne, Director-General of Agriculture, in his presidential address to the Annual Conference of the New Zealand Grassland Association at Dunedin to-night. Mr. Cockayne outlined certain aspects of New Zealand grassland farming and the general philosophy which underlies New Zealand practices. He said that the great importance of grassland in the Dominion could perhaps best be expressed by the statement that 32,000,000 acres were devoted to the production of the grass crop, and less than 1,500,000 acres to other classes of crops. The New Zealand grasslands were producing annually about. 80,000,000 tons of green herbage or an average of somewhat under three tons to the acre. The poorest grazing land did not reach one hundreweight to the acre, while the most productive areas exceeded 20 tons per acre. From this 80,000,000 tons of green herbage there was produced annually 265,000 tons of butter and cheese,. 375,000 meat, of which lamb was the largest single item and 100,000 ton of wool. ' These three commodities represented in an overwhelming degree the Dominion’s international livelihood.“If wool is excluded from these items” said Mr. Cockayne, “We are left with dairy and meat products, which are dependent on the one hand on the cow and on the other hand on the ewe. The point I wish to make is that in New Zealand grassland farming it is the female animal which is the index that must be used to measure production, and it is on an increase in our female livestock that expansion in production comes about. It is essential that female livestock should be fed with nourishing food of a milk-producing character, irrespective of whether they are cows, ewes, or sows and as our female stock are in the main fed with grass, it automatically follows that our grasses must be primarily of a milk-produc-ing character. “Broadly, pasture may be either of a milk producing type or it may not. In the former case it is suitable for milking stock, and in the latter for store stock only. Thus we have the terms “wet stock pasture” and “dry stock pasture.” The essential feaure that determines whether a pasture is of a milk-producing nature or not is the actual age of the herbage itself. In other words vigorously growing or fresh young herbage is suitable The whole objective of grassland farming in New Zealand is to maintain pasture in a young, vigorously growing condition for as long a period of the year as possible. In other words, to develop conditions and management so that the pasture remains permanently juvenile. The ability of a pasture to remain permanently juvenile is influenced by the grassland farmer. The first is. for want of a more definite term, the fertility of the soil. Tne second is the type of herbage itself, again closely connected with the fertility of the soil, and the third is ability to recover rapidly when pruned. This again is connected on the one hand with fertility and the type of plant being pruned. The real, practical essence of a pasture remaining young or becoming old depends on its ability to produce fresh growth after being pruned, or to use the farming term, its ability to recover after grazing. Now let, us examine some of the ways in which a permanent jevenile condition in pastures is brought about or pastures that have become old are rejuvenated. In arable districts, of course, the common method is to let your pastures become old within a few years, generally through the plants originally seeded becoming weak, and being replaced by others that are not of a true milk-producing tvpe or remain only in a young condition for a very limited period of the year. When this condition arises ‘ the land is cropped for a season as so, and the pasture is then renewed. It remains young for a year or so. and the process is repeated. This method works quite well in arable districts, but apart', from being expensive, as the objective of tne grassland farmer is to have permanent rather tnan temporary pastures, the continuous renewal method is of limited application. One of the most important methods of developing fresh supplies of young grass is to prune or eat out the growth, and rely on the immediate fresh growth response, which occurs when any plant is pruned, provided the pruning is done at the most suitable stage, and the plant is one of a type capable of growth response after being cut or eaten back. A whole range of grass land farming practices, having as their objective the development of fresh growth after a rapid pruning of the pasture, have been, developed, but only a few of them need be noted. The crudest form is exemplified by the burning of tussock grassland, or by the burning of got away Danthonia country. The mowing or topping of dairy pastures comes into the same category except that the latter is often necessary, whereas former ought to be avoided except in certain types of second growth pasture land. " The whole theory of subdivision of grassland, be it extensive or intense, is connected up with the pruning theory of young grass production, as it enables manipulation in stock concentration to be

adopted by the farmer. Of course i it is connected up with the better re- i sponse of young grass growth that 1 follows rapid defoliation. Perhaps the most notable rejuvena- ( lion practice by eating out is afforded < by the employment of cattle on nill ; sheep country for the purpose of making feed suitable for ewes and hoggets. The older and stronger' the cattle are the better they are su’ted for the work, and one views rather with alarm the widespread idea that such cattle representing as they do the only agricultural implement mat the hill country farmer can possess, should be sold off at an early age and fattened for the chilling trade. xt | may be, later on. when more of our! hill country is topdressed, that me 1 cleaning up of hill country pastures may be successfully performed bv voung cattle, but over much of it three to four-year-old cattle are essential. The full development of rapid defoliation of grass to provide a furtner supply of young grass is seen in many intensive sheep and intensive dairy farms where adequate fencing enables a very high stock concentration to be adopted for a limited per- , iod on any individual paddock, mil % such. intpnfii.vß Fb.AAp A/nrt dairy ff rms

i are on land of the highest fertility or have been made so over a course of years, and that brings me to the point of the connection between rejuvenation through eating out, and the factor of fertility in permanent young grass production. It is the extent of the vigour of growth, coupled of course with the type of herbage that to a large extent determines the ’ rapidity and amount of response that takes place after the grass is fed off, and in general such vigour is in direct relationship to fertility. It would appear as if the greatest single applied factor that generally increases vigour of growth on most of our pastures is topdressing with phosphatic fertilisers, or I would rather put it another way and say wherever there is a distinct clover response through top-dressing such topdressing represents the easiest and simplest method whereby increased vigour can come about; New Zealand at the present time is using somewhat more than 400,000 tons, mainly of phosphatic fertilisers in the topdressing of'pastures over a wide variety of soils, and ones that differed enormously in initial fertility. Some without ’ topdressing are incapable of maintaining a permanent sward of any description, be it of a milk or store stock type, and others are of good to high initial fertility. The out- • standing feature of the last decade and a half of topdressing,—prior to , ‘that comparatively little was done except in certain districts —i.as been the fact that irrespective ot the initial fertility of the soil, pastures of very high production permanently producing young vigorously growing herbage, have been developed, and this has lead to the formulation of what one may term the surface fertility theory of permanent young grass. Nearly the whole of the grasses and clovers that normally remain permanent on the best pastures on initially rich soils have similar root systems, and develop their root system close to the level of the ground, i.e., all their roots when in a young stage are quite close to ground level. New roots are constantly being developed that pass through the surface layer and spread to lower levels. When topdressing is carried out on soils whose surface fertility is low, a mulch as it were of nutrient material is provided just below growth. >lt would appear as if when a rich surface feeding layer Is provided, irrespective of what may be the fertility at lower levels, if drainage, is adequate, permanent high productive pasture of a milk-producing character can be developed, nor does there appear to be any great range in the quality of fertiliser required, provided the pasture is one that is laid down on cultivated land, treated with two applications of fertiliser within the first few months. It would appear, as I have often stated, that the essential for vigorous permanent young growth is a veneer of fertility, just at ground level, and in most cases this veneer can be provided by phosphatic topdressing provided there is an adequate rainfall, and provided a clover response is brought about. During the past few years there have been many examples throughout New Zealand where previous experience indicated that only inferior grasses could be established, but which now after topdressing are carrying swards capable of producing over 200 lbs of butter fat per acre. It would seem therefore, that the theory of the surface fertility requirement for permanent milk-producing pastures is a sound one. Where, however, climatic conditions lead to long and. repeated drying out of the soil, a thin surface layer of fertility is not sufficient to establish permanently high producing pasture. Let one look for a moment to the position topdressing has reached in New Zealand. At present just about three million acres of grassland is topdressed annually, and one 'would say without hesitation that there is at least another three million acres capable of equal, if not greater, response to that already topdressed. Our present lopdressing bill for fertilisers is somewhere under two million pounds, and at a moderate estimate it is responsible for an added 10 to 12 million pounds worth of production. My suggestion is that the New Zealand farmer should add another two millions to his fertiliser bill and cash in on the result. I have in my address endeavoured to emphasise what I view as some of the guiding principles of grassland philosophy in New Zealand, freely admitting that, they are in the nature of generalisations, and in many cases not of specific application. First and foremost our grassland products are dependent on the adequate feeding of female live stock; female livestock are dependent on adequate supplies of young, vigorously growing herbage “wet stock pasture” maintained as such; repeated supplies of young herbage under a permanent pasture syster are dependent on renewal following pruning or defoliation; efficient pruning that is grazing is dependent on ability to control stock concentration; stock concentration is dependent on the upkeep or improvement of ■ the surface fertility of grassland, and provided this cycle is not broken, permanent. wet stock country results. You may well ask “well have we got any problems left,” and I have to an- : swer “yes, and in plenty.” What I think can be viewed as those really • important from a long view stand- ; point apply in the main to those areas ; of New Zealand where the lie of the fland fits in well with wet stock stand - i ard ideals, but where climatic edndil tions nullify their application, but 1 here such a plant as subterranean ■ clover, when we know more about I it, may play an important part. . There is the great area of 14 mil- ■ lion acre* of tussock grassland, poor- * er to-day than it was a generation

ago, where the problems are funamentally different from those of our lowland or forest—-derived grasslands. There is the broken and steep hill country on which millions have been spent in converting from forest into grass, steadily deteriorating, and where subdivision, stock concentration and topdressing are not applicable. I mentioned earlier that we are topdressing three million acres to-day, and we should at least be doing six, and', if we did probably another 3 million, acres would be benefitted. Add to this area three million I acres of rotation grass in the arable I belt, and that makes 12 million acres. | Our total grassed area is 32 millions, I leaving in round figures 20 millions, I which represent the real and difficult grassland problem of the future. | There are numerous other problems I of more immediate significance, but I refer here to general rather than specific ones; standing out prominently is the question of ragwort con--1 trol, where the judicious combination ■ of sheep with cattle at present of- ■’ fers the best solution, but where arc - the sheep coming from for the pur- - pose, and with the real extension of • lopdrossing as taking place at thf I present, large numbers of additional 5 sheep and cattle will be required. The

conversion of sheep breeding country Into fattening country—another feature that topdressing brings about, is tending to force breed on to unsuitable country, but you will notice that all these problems are connected up with a really adequate supply of livestock, and in this connection a diminution of the live-stock losses, especially with regard to hoggets and a diminution of the high rate of cow replacement would be most valuable Our grassland development work I feel rather got ahead of our live-stock development work, : and that cries aloud for research.