One important adaptation of plants to Phosphorus (P) deficiency is to alter root system architecture (RSA) to increase P acquisition from the soil, but soil-based observations of RSA are technically challenging, especially in mature plants.
Pan et al. developed a new large Brassica-rhizotron system to study RSA dynamics of B. napus in soils at low and high P. RSA parameters measured in polycarbonate plate roots were empirically consistent with analyses of excavated roots. Given that root senescence is likely to occur earlier at low P, crop P deficiency is likely to affect late water and nitrogen uptake.
Pan Yuan, Guang-Da Ding, Hong-Mei Cai, Ke-Mo Jin, Martin Roger Broadley, Fang-Sen Xu, Lei Shi, 2016, 'A novel Brassica–rhizotron system to unravel the dynamic changes in root system architecture of oilseed rape under phosphorus deficiency', Annals of Botany, vol. 118, no. 2, pp. 173-184 http://dx.doi.org/10.1093/aob/mcw083