The effects of season and weather on the growth rate of a ryegrass clover pasture

Summary An experiment is described in which the effects of seasonal climate and of temporary (weekly) weather variations on the growth rate of a pasture of short‐rotation rye grass and white clover were determined. The technique of measurement included replication in time as well as space. Statistical analyses showed significant positive correlations between seasonal trends in growth rate and light and temperature. Positive correlations were also obtained for the weekly fluctuations in growth rate attributable to weather factors. The pasture was irrigated during the summer and early autumn so that water was at all times adequate for growth. The average daily growth rate of the pasture ranged from 10 lb of dry matter (d.m.) per acre in the winter to 120 lb per acre in early summer. The weekly fluctuations in growth rate attributable to weather factors were as large as α 50 % of the weekly growth rate. The potential annual yield of d.m. obtainable from this pasture type growing in this locality, was estimated as 22.000 lb per acre.