Main content area

A grazier survey of the long-term productivity of leucaena (Leucaena leucocephala)-grass pastures in Queensland

Radrizzani, A., Dalzell, S.A., Kravchuk, O., Shelton, H.M.
Animal production science 2010 v.50 no.2 pp. 105-113
Leucaena leucocephala, forage grasses, pastures, yields, farm surveys, farmers, temporal variation, beef cattle, questionnaires, soil types, plant establishment, fertilizers, nutrient management, vegetation cover, plant growth, weeds, liveweight gain, soil fertility, soil quality, phosphorus, sulfur, grazing intensity, Queensland
Leucaena leucocephala subsp. glabrata (leucaena)-grass pastures are productive, perennial and long-lived (>40 years). However, little is known about changes in the productivity of these pastures as they age even though they are grazed intensively and are rarely fertilised. A postal survey of beef cattle producers in Queensland who grow leucaena pastures was conducted. The questionnaire gathered information regarding: property location; extent and age of leucaena pastures; soil type; leucaena and grass establishment methodology; grazing and fertiliser management; and grazier perceptions of changes over time in leucaena productivity, grass growth and ground cover, prevalence of undesirable grasses and weeds, and livestock productivity. Graziers were asked to report on both young ([less-than or equal to]10 years old) and aging (>10 years old) pastures under their management. Eighty-eight graziers responded describing 124 leucaena paddocks covering 11750 ha. The survey results described the typical physical and management characteristics of leucaena pastures in Queensland. Graziers reported a decline in leucaena productivity in 58% of aging pastures, and declines in grass growth (32%) and livestock productivity (42%) associated with declining leucaena growth. Leucaena decline was greater in soil types of marginal initial fertility, particularly brigalow clay, soft wood scrub, downs and duplex soils. Maintenance fertiliser was not applied to most (98%) leucaena pastures surveyed despite significant amounts of nutrient removal, particularly phosphorus and sulphur, occurring over prolonged periods of moderate to high grazing pressure. It is predicted that large areas of leucaena pasture will continue to suffer soil nutrient depletion under current management practices. Research is needed to develop ameliorative actions to reinvigorate pasture productivity.