CAWTHRON INSTITUTE

Hokitika Guardian, 22 August 1930, Page 6

CAWTHRON INSTITUTE

MAKES VALUABLE DISCOVERIES. (By Telegraph—Per Press Association.) ' NELSON, August 21. Important results obtained in the Cawthron Institute experiments in connection with the manufacturing of pastures under the rotational system of grazing were announced to-day by Mr T. -Rigg, Assistant Director and Chief Agriculturist to the Institute. A complete manure consisting of super-phosphates, 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 sulphite has detrimentally affected the pasture 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. Duiing September its effect on the yield was more marked, a daily production of nearly 221bs of dry matter per acre being obtained against 11-Jlbs on untreated pastures. Talcing the figures of 2211) s of dry matter to be the production requirements of an average dairy cow in milk, it 6 would appear that the application of sulphate ammonium per acre would provide an increased stocking of approximately one-third cow per acre for a period of at least six weeks. The chemical data show very definitely that both season and manurial treatment have a pronounced effect on the chemical composition of pasture. Phosphate, potash, and nitrogen have been readily taken up by the pasture plants so that the quantities of these constituents are notably increased. The lime treatment of land has always given a higher percentage of desirable constituents in the pasture grass under manurial treatment than has been the case on unlimed ground. In early spring, the amounts of certain minerals were 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 have decreased almost 50 per cent. Experience has shown (that stock on certain mineral-deficient pastures suffer most from stock ailments at this time.