The effect of urea and cutting treatments on the production of Pangola grass in south-eastern Queensland

Abstract

Urea at rates of 100, 300, and 500 lb N an acre a year, cutting intervals of 4, 8, and 12 weeks, and cutting heights of 2 inches and G inches were applied factorially to a Pangola grass sward in south-eastern Queensland (lat. 275) over a period of two years. Nitrogen applications increased the yields of dry matter and nitrogen, the nitrogen content and nitrogen recovery ; the responses were marked, significant, and quadratic. Responses to cutting intervals were significant and linear, but cutting height had only a slight effect and this was restricted to yield of dry matter. Maximum yields of dry matter were 21,000 lb an acre a year, of nitrogen 200 lb an acre a year, and the mean yield of nitrogen was 45 per cent of that applied. Growth was markedly seasonal ; production of dry matter in tops varied from about 1 lb an acre a day in winter to over 100 lb an acre a day in summer. It is considered that the major physical limitations to growth in this region are water shortage in summer and low temperatures in winter. Little growth was made when the average screen minimum temperature was less than 52¦F, or the average night temperature less than 58¦F, the maximum having less influence.