PROBLEMS OF THE FARMER.

Press, Volume LXV, Issue 19669, 12 July 1929, Page 12

PROBLEMS OF THE FARMER.

HOW SCIENCE MAY HELP. j DR. DKNHAM'S ADDRESS. j A. survey of present and future problems before the farmer in Canterbury was made by Dr. H. G. Denham, of Canterbury College, last night, when j lecturing to farmers who are attending a short course at Lincoln College. : The lecture was held in the Canter- ! bury A. and P. Association's rooms. I Dr. Deniiam dealt mainly with pastures, animal nutrition, and seed and I plant research. j About 94.2 per cent, of our total exports came from the pastures, said the | so justification for Neiv j Zealand's participation in such work I was apparent. j Deaimg with the question generally, ] Dr. Deniiarn said there were mainly j two questions involved: The actual de- 1 ficiency of certain minerals in pastures which might give rise to diseases and mal-nutrition in stock; then there was the whole tubject of animal nutrition. The proteins, which were the energyproducing substances present in fodder, were of prime importance, but, in addition, the animal body required a small percentage of inorganic minerals which ultimately, on decomposition, formed the ash. It had been hitherto assumed that the mineral content of ordinary foodstuffs would suffice for the needs of the animal. This was a fallacy, for it had been found that many important problems of nutrition were connected with the mineral constituent. For example, an excess of potassium prevented the heart muscles from relaxing, while a deficiency had the opposite effect. The skeleton of an animal acted as a clearing house through which the supplying of certain minerals, such as calcium and phosphorus, were regulated, and any deficiency in the amount of either of these necessary substances would impair the rigidity of the skeleton. Thus, during heavy lactation, a cow had to draw upon its reserves of lime. Lack of iron was the cause of "bush sickness'' in cows, so prevalent over parte of the North Island. Iron was not found in milk. A young pig had sufficient iron in its system to supply it for three weeks, but if it grew so quickly that it used up this supply too soon, acute anaemia set in, often followed by death. A deficiency of iodine in the diet of pigs led to unhealthy progeny. largely hairless, and these always died. Much research in animal nutrition bad been done in Scotland, and it had been found that the Scottish hill pastures were markedly poorer in all mineral constituents except sodium than the pastures in the lowlands. In spite of this, there was very little difference in the calorific values of the various pasture grasses. Mineral content varied with the seasons, most constituents rising steadily through the spring, passing through a maxi--1 mum in summer, and falling rapidly to a minimum in autumn. A disease which caused an appreciable loss during the lambing season had been attributed to the unbalanced natural ratio which manifested itself in a disturbance of the health of the lamb, often causing death. It was important that the farmer should determine the exact stage in the life of the plant, when it paid the farmar 10 feed it off. The whole of efficient pasture management had for its objective the maintenance of the pasture herbage in that condition of growth which would enable the stock to produoe their best when grazed upon it. It was important, too, to discover if the application of fertilisers had any effect on the mineral content of pasture. A great deal of top-dressing had been done, often on the hit-or-miss principle, but sufficient justification for the extension of this work was given by the statement that on some 14 farms the carrving capacity had been raised from half to two and a quarter sheep per acre by using 2i to 3 per cent, of superphosphate per acre at an average cost of 6s 2d per acre for manure.

Turning to the means for solving the problems raised, the Professor said the first thing needed was a supply of trained men. In seed and pfnnt research the work of Lincoln College in producing a variety of wheat known as College Hunters had increased the yield to a great extent. Then there was the control of root crop diseases such as dry rot in swedes, which had been responsible for big failures in these crops in Canterbury. There were a large number of "agricultural diseases that were seed-born, and suitable seed treatment was the logical method for their control. The Professor also outlined improvements which might be carried out in the dairying industry.