Allocation of photosynthesized carbon in an intensively farmed winter wheat-soil system as revealed by 14CO2 pulse labelling

Sci Rep. 2018 Feb 16;8(1):3160. doi: 10.1038/s41598-018-21547-y.

Abstract

Understanding the rhizodeposited carbon (C) dynamics of winter wheat (Triticum aestivum L.), is crucial for soil fertility and C sequestration. Pot-grown winter wheat was pulse labelled with 14CO2 at the key growth stages. 14C in the shoots, roots and soil was measured at 5 or 2 days after 14C-labelling (DAL 5/2) at each growth stage and at harvest. The 14C in the shoots increased from 4% of the net 14C recovered (shoots + roots + soil) during tillering to 53% at harvest. Approximately 14-34% of the net 14C recovered was incorporated into the soil. Allocation of photosynthesized C was extrapolated from the pot experiment to field condition, assuming a planting density of 1.8 million plants ha-1. The estimated C input to the soil was 1.7 t C ha-1, and 0.7 t C ha-1 of root residues was retained after wheat harvest; both values were higher than those previously reported (0.6 and 0.4 t C ha-1, respectively). Our findings highlight that C tracing during the entire crop season is necessary to quantify the temporal allocation of photosynthesized C, especially the contribution to soil carbon in intensified farming system.

Publication types

  • Research Support, Non-U.S. Gov't