GRASS LAND FARMING.

Otago Witness, Issue 3829, 2 August 1927, Page 12

GRASS LAND FARMING.

The management of grass land in the Dominion has become a matter of great importance now that so much land is left unploughed. Land that in the ordinary course would have been ploughed up, cropped, and turnipped, and after a year or two sown down in grasses and clovers, is left in grass, and undergoes top-dressing with fertilisers, the idea being to maintain a good sole of pasture and avoid the expense of cultivation. Given the manure containing the particular ingredients lacking in the soil, there is no doubt great good will result without unreasonable outlay of labour or capital. The subject of grass land treatment to-day is evoking a vast amount of attention, not only in Australia, but also in Great Britain, where one would have thought the problem of grass husbandry had long ago been solved. The English Ministry gave the subject pride of place at its recent conference of agricultural advisers at Cambridge. Dr J. B, Orr, director of the Powell Institute, drew attention to the important part mineral substances played in nutrition. He pointed out that the actual analysis of herbage shows that natural grasses vary in their mineral content from locality to locality, and that the instincts of wild animals can be correlated with the presence or absence of certain minerals in the food they choose. Scientists are now agreed that deficiency of minerals leads to malnutrition; want of lime may produce sterility, weakness of limbs or joints; deficiency of phosphorus causes lack of co-ordination of movements; lack of both lime and phosphorus seems to predispose tuberculosis. Depletion of minerals in an exporting country of primary products, such as New Zealand, has been very great for years now, and ho wonder, as the result of the exports of thousands of tons of meat, dairy produce, wool, etc., that our herbage is of poorer quality and not standing up to the insistent demand of graziers. Important as is the question of mineral substances in nutrition, we are led to believe that the paper which aroused most interest at the conference was Mr W. Burton's account of the Hohenheim system of sectional grazing, coupled with nitrogenous manuring. This system has been referred to from time to time in this paper, and briefly consists in stimulating the continuous growth of herbage by frequent applications of a nitrogenous manure and the rapid grazing down of the young flush of grass by stock, followed by a period of about 20 to 30 days’ rest, during which a further application of manure is made if necessary. Contrary to general belief, this treatment has been found to have no injurious effect on the herbage, no mat is produced, and the growth, of clover is stimulated. It is recognised, of course, that in ordinary farming only a small portion of the grass land could be treated so intensively; but there are perhaps possibilities in the adoption of some such treatment in regard to, say. second-class pasture. In summing up the trend of the conference, Professor Wood pointed out that hitherto grass had been treated as a natural product, which needed no special management and might be left to the mercy of Providence. In the past the attention of scientists had been concentrated on arable husbandry, and very little research had been done in relation to grass land productivity. Recently, however, the botanist, chemist, and physiologist had got together, and many new facts had come to light which would enable a reasoned attack to be made on what seemed likely to become the agricultural problem of the day: how to make the best use of the land rapidly turning to grass. The views put forward at the conference are interesting, and no doubt some of the theories enunciated will be put into practical application on the farm. The unfortunate part is that no one treatment will suit all lands, and farmers have to satisfy themselves in regard to the best fertiliser to use. In the Dominion we are too prone to pin our faith upon phosphorus as the desideratum of all lands. No doubt there has been a drain upon the phosphorus contained in the soil, but there has been an equal, if not greater, drain upon the nitrogen and available potash of the soil, until there is a general exhaustion of the chief fertilising elements of plants. Inasmuch as the results of experiments

show that stock can take the mineral elements out of feeds more efficiently while they are an green pasture than under any other practical conditions, it is timely to suggest that more attention should be given to the quality of the pasture than is the case at present. If the pasture is knowingly deficient in minerals, it is well worth giving consideration to the question whether it would not be wise to give stock access to, say, a mixture of equal parts of salt, bone meal, and finely-ground limestone.