Research conducted by The University of Western Australia (UWA) School of Plant Biology and Institute of Agriculture has demonstrated that several herbaceous legumes may be viable alternatives to lucerne under low phosphorus conditions for West Australian farmers in areas where lucerne performs poorly.
The research compared the growth of 10 native and exotic herbaceous legumes to lucerne growing in glasshouses, supplied with different levels of phosphorus.
The study found that four species, Bituminaria bituminosa, Glycine canescens, Kennedia prostrata, and K. prorepens, grew better than lucerne in low phosphorus conditions and that two species, B. bituminosa and G. canescens, used phosphorus applied to soil more efficiently than other species where low phosphorus was a problem.
Funded by the Australian Research Council (ARC), Department of Agriculture and Food Western Australia (DAFWA) and Heritage Seeds, the research could have important implications for WA farmers, according to Research Associate, Dr Jiayin Pang, School of Plant Biology,UWA.
Other project collaborators include ChemCentre, Facey Group and Mingenew Irvin Group.
"Developing new perennial pasture legumes that take up or use phosphorus more efficiently than lucerne is important in the face of dwindling global phosphorus reserves and the rising cost of fertilisers," Dr Pang said.
"As well as this, many farmers need a viable alternative to lucerne because it's poorly adapted to acidic sandy soils, waterlogging and salinity and doesn't do well in hot and dry conditions."
Dr Pang said many of the legumes tested were native species well adapted to local environmental conditions, such as low rainfall, acidic soils and low fertility.
The research also found that exotic perennial legumes, such as B. bituminosa, could also fill low phosphorus niches where lucerne production was poor.
"Although promising, the results of this glasshouse study will need to be validated with long term field studies," Dr Pang said.
"That will identify if native perennials will accumulate large amounts of phosphorus from heavily fertilised, high phosphorus soils."
Many native legumes regulate phosphorus uptake poorly when soil phosphorus supply is increased, resulting in phosphorus toxicity.
"It will also determine if native and exotic legumes can use phosphorus already in the soil more efficiently, thereby reducing the need for additional fertiliser application," Dr Pang said.
Large scale use of phosphorus has seen a rapid depletion of global reserves, which are expected to halve by 2060.
This poses a significant challenge for Australian agriculture with its phosphorus deficient soils and the heavy use of phosphorus fertiliser.
Australian native and novel exotic perennial legumes, such as those identified and currently being developed by Future Farm Industries CRC and UWA, could alleviate this problem.
Caption to Photograph: Dr Jiayin Pang monitoring soil moisture content, using Diviner2000 soil moisture probe, of novel pasture legume species at UWA glasshouse experiments.
Dr Jiayin Pang (Plant Biology) (+61 8) 6488 4546
Professor Kadambot Siddique (UWA IOA Director) (+61) 8 6488 7012 / (+61 4) 11 155 396
Sally-Ann Jones (UWA Public Affairs) (+61 8) 6488 7975 / (+61 4) 20 790 098