Abstract
The readily available global rock phosphate (P) reserves may run out within the next 50-130 years, causing soils to have a reduced P concentration which will affect plant P uptake. Using a combination of mathematical modelling and experimental data, we investigated potential plant-based options for optimizing crop P uptake in reduced soil P environments. By varying the P concentration within a well-mixed agricultural soil, for high and low P (35.5-12.5mgL(-1) respectively using Olsen's P index), we investigated branching distributions within a wheat root system that maximize P uptake. Changing the root branching distribution from linear (evenly spaced branches) to strongly exponential (a greater number of branches at the top of the soil) improves P uptake by 142% for low-P soils when root mass is kept constant between simulations. This causes the roots to emerge earlier and mimics topsoil foraging. Manipulating root branching patterns, to maximize P uptake, is not enough on its own to overcome the drop in soil P from high to low P. Further mechanisms have to be considered to fully understand the impact of P reduction on plant development.
A collaboration between Southampton and Bangor University address how the alteration of root system architecture could (by breeding or genetic manipulation) produce greater P uptake. Experimental results of wheat roots are measured, from lengths and widths, including root hairs and a phosphate uptake profile. The data is used in conjunction with a mathematical model, which can simulate new root systems and the effects they have on P uptake. Due to the readily available global rock phosphate (P) reserves running out within the next 50-130 years, this work is of importance in assessing how crops will cope in soils with a reduced P concentration. We would be delighted if this paper was published in Plant, Cell & Environment, to further advance the P shortage awareness and potential solutions for its inevitable arrival.
