FARMING NOTES

Bay of Plenty Beacon, Volume 1, Issue 100, 13 December 1939, Page 2

FARMING NOTES

DAIRYING PASTURES By Mr E. Bruc » Levy, Director Grasslands Division, Plant Research Bureau, Palmerston North. The ideal pasture, whether for the dairy cow, for baby beef or for fat lamb production is essentially linked up with a grass-clover sward, ever growing', ever-green, and of high nut ritive value. Pasture-making in New Zealand, with its comparatively mild and equitable climate and high rainfail, depends on three inter-related factors:— (1) Soil fertility that will produce (2) A high production sward that will carry. (3) A high per acre concentration of stock. These three factors are basic to the production of luscious, high yielding, permanent dairying pastures, and in this article I want to show by means of practical illustrations of land and pasture development how the three main factors operate. In all development there must be a driving force, and for a force to be applied there must be a medium through which to apply that force. In pasture development phosphate or phosphate and lime is the main driving force, and the mechanism by which this force is applied is the clover of the pasture, and the more efficient the clover is as a producer, the more efficient is the exploitation of the phosphate applied. The clover prepares the way and makes possible the second phase in the development

The clover plant in itself is a nitrifier of the soil, but the ipain value of the clover is to make possible stock concentration on the area to provide the second great drn ing force, nitrogen, in the form of stock nitrogen, which is the lifeblood of the grasses of the sward. Thus phosphate promotes clover, the clover provides food for the stock that provides the nitrogen for the grass, and the grass and clover together build a still higher carrying capacity which when up to a cow to the acre is attained, provided the animal residues are uniformly applied to the grazed sward, satisfies the nitrogen requirement of the grasses of the sward. When this point is reached, provided the phosphate is still applied to maintain the clover plant at full production, the maximum yield of pasture is attained. Special soils may call for special treatment, drainage may be necessary, and othc minerals, such as lime, potash, or cobalt, may be required.

On extremely fertile soils, where ; the natural growth provides the sus- ; tenance of a dairy cow to the acre, the development proceeds without ! the driving force of the phosphate, but such areas arc rare in New Zealand. The More Stock That Can Be Carried Per Acre, The Better The Grassland Becomes. In the recent land development of the difficult pumice country in the last 20 to 30 years' development of the "W'aikato; in the more recent development of the once despised gum lands of the north; in the conversion ol the second-class heavy wet clays; in the development of peat and sand country: in the conversion of forest to grass, and in the vast development of our scrub-covered marginal lands to pasturage, the principles enunciated above are clear ljr shown. The more stock that can be carried and adequately fed per acre the better the grassland becomes, and, conversely, the less stock that any land can adequately support per acre, the less chance is there of land improvement. In this I want tc stress adequate feeding. Stock adequately fed makes the country, but stock inadequately fed ruins the country. Principle of Concentration. The principle of stock concentration in dairying brings up the question of grazing management. One sees frequently the one or two night paddocks about the milking shed, often over supplied with stock nitrogen. One sees also that state of progressive deterioration of the pastuures as the distance from the shed is increased, and this state of affairs is often intensified in the one-pad-dock farm, the stock grazing for a

while on the back portions of the one-paddock farm to migrate homewards with the feed in its belly, to be voided out later on the areas nearer the milking sheds. It has been reliably recorded that a lull-led cow will consume approximately threefifths of its daily ration during the day and two-fifths at night, and where the herd is out grazing in the day the tendency is for the residues of the food collected in the day to be voided in the night paddock, particularly the afternoon grazings, whereas little residue from food eaten in the. night paddock is conveyed back to the day paddocks in view of the fact that the cow eats practically nothing after midnight, and, therefore, goes out empty to the day paddocks. This all tends to emphasise the need for a stricter control of grazing, and smaller paddocks to which the grazing animal can be confined are indicated.

To my mind, the high carrying capacities recorded under the system of strict rotational grazing are based largely on the principle of a uniform spreadback of the stock residues to the pasture sward in the course of their intensive grazing of the area. The spell between the grazings provides more feed, the high per acre stock concentration means uniform efficient utilisation, and the stock residues are evenly spread in the course of that grazing. The electric fence is proving very useful in bring ing about this rotational grazing of special feeds at the present time on the dairy farm of the College. Driving Force in Countries Overseas

During my trip overseas I paid special attention to pasture manuring in Great Britain and on the Continent, and the principle underlying the soil fertility upkeep of those countries is the stable manure of the animal itself. Whereas in New Zealand the driving force is phosphates to produce the clover that is grazed in situ, overseas the driving force is largely inbouglit concentrates, and home-grown cereal and root crops and hay, which are fed to housed stock during the longer winter months. The accumulation of dung and urine over that period and its subsequent application to the land or pasturage is in a large measure responsible for the soil fertility upkeep of Great Britain and the Con

tinent. Poulltry fed and housed in moveable folds across the grasslands and tethered pigs !hat are fed out concentrates on the grasslands also contribute to the problem of soil fertility upkeep. Artificial manures are also used on grassland during the spring, more particularly in the more intensively-farmed areas for liquid milk production. In the foregoing it will be obvious how parallel is the soil fertility maintenance of New Zealand with that of the Old Land with the marked exception that the animal in New Zealand can be. made to distribute its own residues itself in the course of its all the year round grazing. I feel confident New Zealand has no fear of soil fertility depletion whilst the country is made to support a large stock population that is adequately fed.