Track 2-11: Plant Nutrition and Nutrient Cycling
Description
Phosphorus (P) fertilisers are important for high production in many grassland systems. However, there are increasing environmental, economic and strategic issues associated with using P, which is a non-renewable and “effectively finite” global resource. We review the P balance of temperate pastures to identify the factors that contribute to inefficient P use and discuss ways to improve P use efficiency. The most immediate gains can be made by ensuring that pastures are not over-fertilised. Plants with low critical P requirements, particularly as a result of better root foraging, will be important. Root traits such as fine roots (root diameter), branching, length and root hairs, and mycorrhizal associations all contribute to improved root foraging; some are amenable to plant breeding. Plants that can “mine” sparingly-available P in soils by producing organic anions and phosphatases are also needed; as are innovations in fertiliser technology. Soil microorganisms play a crucial role in P acquisition by pastures but are not particularly amenable to management. Selection of pasture species for root characteristics offers a more realistic approach to improving P efficiency but progress, to date, has been minimal. Traditional plant breeding, augmented by marker assisted selection and interspecific hybridisation, are likely to be necessary for progress. Inevitably, P efficient pastures will be achieved most effectively by a combination of plant genetic, fertiliser innovation and management responses. Success will bring economic and environmental benefits from reduced P fertiliser use, with consequent benefits for global resource and food security.
Citation
Simpson, Richard J.; Richardson, Alan E.; Nichols, Shirley N.; and Crush, James R., "Efficient Use of Phosphorus in Temperate Grassland Systems" (2020). IGC Proceedings (1993-2023). 2.
https://uknowledge.uky.edu/igc/22/2-11/2
Included in
Efficient Use of Phosphorus in Temperate Grassland Systems
Phosphorus (P) fertilisers are important for high production in many grassland systems. However, there are increasing environmental, economic and strategic issues associated with using P, which is a non-renewable and “effectively finite” global resource. We review the P balance of temperate pastures to identify the factors that contribute to inefficient P use and discuss ways to improve P use efficiency. The most immediate gains can be made by ensuring that pastures are not over-fertilised. Plants with low critical P requirements, particularly as a result of better root foraging, will be important. Root traits such as fine roots (root diameter), branching, length and root hairs, and mycorrhizal associations all contribute to improved root foraging; some are amenable to plant breeding. Plants that can “mine” sparingly-available P in soils by producing organic anions and phosphatases are also needed; as are innovations in fertiliser technology. Soil microorganisms play a crucial role in P acquisition by pastures but are not particularly amenable to management. Selection of pasture species for root characteristics offers a more realistic approach to improving P efficiency but progress, to date, has been minimal. Traditional plant breeding, augmented by marker assisted selection and interspecific hybridisation, are likely to be necessary for progress. Inevitably, P efficient pastures will be achieved most effectively by a combination of plant genetic, fertiliser innovation and management responses. Success will bring economic and environmental benefits from reduced P fertiliser use, with consequent benefits for global resource and food security.
