The influence of weather on the quality of tropical legume pasture during the dry season in northern Australia. IV. Geographic variation in risk of spoilage of standing hay

Abstract

This paper assesses the geographic variation in northern Australia of the risk of deterioration to the point of 'spoilage', including both the beneficial and the deleterious effects of rain. The procedure is a modified water balance in which leaf shedding is driven by decline in soil water storage, and moulding is governed by the rate of evaporation following a rainfall of 2 mm or more.For 28 stations, from the West Kimberley to Central Queensland, an average of 40 dry seasons have been analysed for the periods when the legume would have been green, dry but unspoilt, and spoilt. A 'dry leaf' nutritional strategy is feasible where the dry seasons are reliably rainless. Even in regions with a high risk of rain, if green leaf is maintained for a considerable time in the dry season there is also a low risk of spoilage, and the use of non-deciduous legume species in these regions and elsewhere is discussed.