MANURING FOR MILK

Shannon News, 16 January 1925, Page 4

MANURING FOR MILK

An experiment to estimate the improvement of pasture produced by artificial fertilisers, by the practical method of grazing milk cows on the plots and weighing - the milk, was started last year at a British Farm Institute. The field selected for the purpose is on a sandy loam and nas refused to respond in the past to repeated treatments with different kinds of phosphatic fertilisers. The herbage has been consistently poor for years, and characterised by an almost total lack of clovers or other iegumiuous plants. As the field appeared to be sour, it Was decided first of all to lime it, and this was carried out .in February, using 2 tons of ground caustic lime per acre. The field wa s afterwards divided into three plots, each equalling 31 acres, and two months later one plot was treated with 4cwt superphosphate -(30 per cent) per acre, another was treated with 4cwt superphosphate (30 per cent) plus lcwt sulphate of potash per acre, and the other plot was given no manure at all. On the ,12th May, three cows were put on each of the plots, but in sequence of the rapid improvement in the quantity and quality of the herbage on the plot which had received the superphosphate and potash, .as evidenced by the growth of clovers and fine grasses, it whs considered necessary shortly after the commencement of the experiment to put an extra cow on this plot in order to stock it adequately, whereasi the other two plots remained stocked with only three cows, the superphosphate by itself having not yet produced any marked improvement. The plots continued to be grazed until 20th September, that is, making a grazing period of 18 weeks. During this time the cows were changed over from plot to plot at the end of each fortnight, so as to even out as far as possible effects of any natural irregularities in the field. The extra cow on the superphosphate and potash plot was not transferred, but remained on this plot throughout the period. At the end of the period the yields of milk from the various plots were as follows: —No manure, 881 gallons; superphosphate, 870 gallons; superphosphate and potMh, 1072 gallons.

These figures show that the Increase in milk production from the addition of superphosphate and potash was approximately 191 gallons which, valued at 1/- per gallon, leaves a net profit of £5 9/- per plot after paying for the manures.