Fertilization trajectory of the root crop Raphanus sativus across atmospheric pCO2 estimates of the next 300 years

▶ Very high pCO2 levels increase plant biomass, particularly below ground. ▶ The trajectory of the biomass response follows a hyperbolic curve. ▶ A significant percentage of the net increase in biomass occurs above 700 ppmv. ▶ The biomass increase did not carry a proportional increase in N-demand. ▶ Stable carbon isotope analyses confirmed that biomass was not affected by environmental stress.