MANURING PASTURES.

Timaru Herald, Volume CXXV, Issue 18652, 22 August 1930, Page 11

MANURING PASTURES.

CAWTHRON INSTITUTE EXPERIMENTS. By Telegraph—Press Association. NELSON, August 21. Important results obtained in the Cawthron Institute experiments connected with the manuring of pastures under a rotational system of grazing, were announced to-day by Mr T. Rigg, assistant Director and Chief Agriculturist to the Institute. Mr Rigg stated that a complete manure, consisting of superphosphate, sulphate of potash, and sulphate of ammonia, has given the best results in maintaining both the yield and quality of pasture. In the absence of potassic manures, ammonium sulphate has detrimentally affected the pasture’s sward, the percentage of clovers being notably reduced. Suitable temperature and moisture conditions influence greatly the rapidity and magnitude of the effect of ammonium sulphate. Applications made in early August gave an increased production of nearly 100 per cent, during this month. During September its effect on the yield was more marked, a daily production of nearly 221 b. of dry matter per acre being obtained, against 11* lbs. on untreated pastures. Taking a figure of 22ilbs. of dry matter to be the production requirements of an average dairy cow in milk, it would appear that the application of one cwt. of ammonium sulphate per acre would provide an increased stocking of i approximately one third of a cow per acre for a period of at least six weeks. Chemical data show very definitely that both season and manurial treatment have a pronounced effect on the chemical composition of a pasture. Phosphates, potash, and nitrogen have been readily taken up by pasture plants, so that the quantities of these constituents are notably increased. Lime treatment of land has always given a higher percentage of desirable constituents in pasture grass under manurial treatment than has been the case on unlimed ground. On a number of pastures it has been found that chemical composition is most suitable for growing or lactating animals in mid-spring and autumn. In early spring the amounts of certain minerals have been found to be somewhat low. At the end of December, particularly during drought periods, the chemical composition of pastures tends to be poor. In certain poor pastures the amount of phosphate and protein has decreased almost 50 per cent. Experience has shown that stock on certain mineral-deficient pastures suffer most from stock ailments at this time.