The influence of temperature and available nitrogen supply on the growth of pasture in the spring

Abstract

In recent years a number of workers have investigated the influence of nitrogenous fertilizers on the growth of pastures. In some cases they have claimed that such fertilizers lengthen the grazing season by producing grass earlier than normal in the spring, but no research has been carried out on the factors controlling this spring growth. Watson et al. (15) in a study of the influence of nitrogenous fertilizers on the seasons’ yield of rotationally grazed pasture at Jealott's Hill, showed that in 1 year ammonium sulphate applied at the rate of 23·2 lb. nitrogen per acre in March enabled the treated plots to be grazed some 14 days earlier than the control. Richardson(13) found that 44·8 lb. nitrogen per acre gave marked increases in yield. Woodman & Underwood(16), however, claimed that ammonium sulphate (14·5 lb. nitrogen per acre) produced no strikingly higher yields.