The aim of the experiment was to determine the mass yield and amount of total carbon accumulated by spring rye biomass in individual stages of growth determined according to the BBCH scale (Biologische Bundesanstalt, Bundessortenamt und CHemische Industrie): BBCH 30-31 – leaves, BBCH 55-59 – whole plants, BBCH 89-92 – grain and straw). The required results were obtained by conducting a field experiment (2009-2011) which tested the effect of the application of nitrogen (0, 30, 60, 90 kg ha−1) and sulphur (0, 40 kg ha−1) on biomass yield, carbon content and accumulation, and also the C:N ratio. N application in the amount of 60 and 90 kg ha−1 was shown to have the most beneficial effect on biomass yield at each stage of growth. Carbon was accumulated in the amount of 1 294 kg ha−1 by the leaves (BBCH stage 30-31), 2 365 kg ha−1 by the whole plants (BBCH 55-59), 1 334 kg ha−1 by the grain (BBCH 89-92), and 2 062 kg ha−1 by the straw (BBCH 89-92). The total accumulation of carbon by the dry matter of grain + straw increased up to the application rate of 90 kg N ha−1 following the addition of sulphur. The average total accumulation of C was 3 408 kg ha−1. The unit accumulation of carbon was reduced following the application of 30 kg N ha−1, but increased significantly with the level of nitrogen applied, averaging 892.7 C t−1. In general, it may be concluded that under conditions without manure application, ploughing the green matter and straw of spring rye is a good source of carbon in the soil, and is furthermore a technique aimed at limiting global warming by reducing greenhouse gases emissions.