Shoots of white clover plants were pulse-labelled with in order to establish the partitioning of recently assimilated carbon among the different parts of the plant–soil system with special interest in below-ground compartments. The did not change significantly after 24 h chase period. Leaves and stolons contained more than half of the total radioactivity recovered (%TRR). Soil residues (microbial biomass and non-metabolised rhizodeposits) accounted for 7%TRR and rhizosphere CO2 was 25%TRR. In order to investigate seasonal effects on assimilate partitioning below ground, we compared low photoperiod and day/night temperature conditions (10 h—20°C/18°C, PTL treatment) with high photoperiod and day/night temperature conditions (16 h—25°C/20°C, PTH treatment). Plants of PTH conditions favoured partitioning to leaves at the expense of storage organs such as stolons and roots. This was supported by distribution of the relative specific activity (RSA) which indicated a significant higher activity of leaves compared to roots. The reduction of allocated to roots (from 11%TRR in PTL treatment to 7%TRR in PTH conditions) was accompanied by a reduction of found in rhizosphere CO2 (from 25%TRR to 12%TRR) and in soil residues (from 7%TRR to 3%TRR). This indicated that rhizodeposition of recently fixed carbon is correlated to C allocation to roots. A moderate defoliation (27% of leaf biomass removed) did not modify within the plant–soil system. A severe defoliation (51% of leaf biomass removed) increased allocated to remaining leaves from 28%TRR to 37%TRR at the expense of stolons. Partitioning of labelled assimilates to below ground remained unchanged. It is suggested that the age of a plant strongly influences its response to leaf removal.