Improving phosphorus efficiency in cereal crops: Is breeding for reduced grain phosphorus concentration part of the solution?

241

185

Legacy phosphorus (P) that has accumulated in soils from past inputs of fertilizers and manures is a large secondary global source of P that could substitute manufactured fertilizers, help preserve critical reserves of finite phosphate rock to ensure future food and bioenergy supply, and gradually improve water quality. We explore the issues and management options to better utilize legacy soil P and conclude that it represents a valuable and largely accessible P resource. The future value and period over which legacy soil P can be accessed depends on the amount present and its distribution, its availability to crops and rates of drawdown determined by the cropping system. Full exploitation of legacy P requires a transition to a more holistic system approach to nutrient management based on technological advances in precision farming, plant breeding and microbial engineering together with a greater reliance on recovered and recycled P. We propose the term 'agro-engineering' to encompass this integrated approach. Smaller targeted applications of fertilizer P may still be needed to optimize crop yields where legacy soil P cannot fully meet crop demands. Farm profitability margins, the need to recycle animal manures and the extent of local eutrophication problems will dictate when, where and how quickly legacy P is best exploited. Based on our analysis, we outline the stages and drivers in a transition to the full utilization of legacy soil P as part of more sustainable regional and global nutrient management.

Section: Plant Breedingmentioning

confidence: 98%

Integrating legacy soil phosphorus into sustainable nutrient management strategies for future food, bioenergy and water security

Rowe

Withers

Baas

et al. 2015

241

185

“…Error bars are standard errors of the difference for comparison of genotypes in a certain environment. See Table 1 for details on genotypes and environments From a breeding perspective, it may be feasible to minimize the removal of P from fields by lowering the amount of P in grain (Raboy 2009;Rose et al 2013b). Traits that could be targeted include selecting for a lower P harvest index (PHI: proportion of total plant P found in grains) or simply breeding for lower grain P concentration.…”

Section: Low Grain P Concentrationmentioning

confidence: 99%

Integration of P acquisition efficiency, P utilization efficiency and low grain P concentrations into P-efficient rice genotypes for specific target environments

Vandamme¹,

Rose

Saito

et al. 2015

Self Cite

Poor yields in low-input farms and high fertilizer and environmental costs in high-input farms call for more efficient use of phosphorus (P) in rice systems. One approach to increasing the P efficiency (PE) of cropping systems is to develop P-efficient genotypes. Two key traits have been thought to contribute to genotypic PE, namely the efficiency at which P is taken up (PAE) and at which P taken up is converted to biomass (PUE). Low grain P concentration (LGP) has recently been proposed as a third key trait that could improve the PE of a system through reduced P removal with grains. Screening methods for PAE, PUE and LGP are discussed with particular focus on interactions among these traits and the potential to exploit genotypic variation for breeding P-efficient rice genotypes targeted to specific environments. Further, potential changes in nutrient budgets within the known scope of genotypic variation for key PE traits in rice were evaluated. At low to medium yield, simulated yield increased with 40-60 and 15 % by increasing PAE and PUE respectively. Higher PAE increased P removal with 1-2 kg P ha -1 at low to medium yields, leading to accelerated P mining when no P is applied. Limited scope exists for reducing P mining by a LGP trait in severely P-deficient systems, but P removal from fields can be reduced with 0.5-5 kg P ha -1 by a LGP trait at medium to high yields. Maximal gains in efficiency can be achieved by integrating key traits into P-efficient genotypes.Keywords Grain P concentration Á Phosphorus Á P cycle Á P efficiency Á P mining Á P removal Á Rice Á Rice breeding Electronic supplementary material The online version of this article (

“…In addition, the use of plant species or varieties which maintain relatively more P in non-consumable tissues (i.e. those which are not sold for food production) combined with shifts in farm practices towards increased processing and tilling of these plant residues would lead to a higher efficiency of domestic P recycling and reduction in overall P-fertiliser need (Rose et al 2013). Several imbalances can occur at the plant scale leading to, for instance, suboptimal plant growth when P need is larger than P availability, or to inefficient P use when P need is smaller than P availability.…”

Section: The P Conceptual Modelmentioning

confidence: 99%

The future of phosphorus in our hands

Shepherd

Kleemann

Bahri-Esfahani³

et al. 2015

We live in a global phosphorus (P) system paradox. P access is becoming increasingly limiting, leading to food insecurity but at the same time an overapplication or abundance of P in many agricultural and urban settings is causing environmental degradation. This has been recognised in the academic literature and at regulatory levels, but swift action and multilevel cooperation of all stakeholders is required to ensure the economically, environmentally and socially responsible use of P. To provide foundations for future cooperation, a conceptual model describing the elements of P need, P availability and P use in different systems and at different scales was developed during the Young Scientists Workshop in P Week 2014 in Montpellier, France. Here we describe our extended conceptual model and a theoretical P balance calculation tool for describing multi-scale P balances and imbalances to impartially advise all stakeholders on more sustainable P use across the world.