Data from: Soil carbon accumulation differences: allocation of visible plant biomass, carbon and nitrogen in two turfgrasses

<p><span>Carbon accumulation in turfgrass soils by plant material may be beneficial to CO₂ sequestration and soil health, but at high rates can easily lead to declined turfgrass quality (i.e. thatch and mat layer formation). In a field study it was investigated how the fraction of visible plant biomass of turfgrass (sub)species monocultures, with two or three varieties&nbsp; as monoculture per (sub)species, and its C and&nbsp; N concentration and CN ratio in this visible plant biomass in thatch, mat and soil layers contributes to C accumulation. In total three <em>Festuca rubra</em> subspecies; <em>Festcua rubra commutata</em> (Frc), <em>Festuca rubra trichophylla </em>(Frt), <em>Festuca rubra rubra</em> (Frr), and three Agrostis species; <em>Agrostis canina</em> (Acn), <em>Agrostis capillaris</em> (Acp), Agrostis stolonifera (As), were studied.&nbsp;The study was conducted on 3 years old turfgrass demonstration fields of two turfgrass seed companies: <em>Festuca rubra</em> subspecies samples were collected at a site of Barenbrug in Wolfheze (52&deg;00&acute;N, 5&deg;46&acute;E), and <em>Agrostis </em>species were sampled at a site of DLF in Moerstraten (51&deg;32&acute;N, 4&deg;20&acute;E), both in the Netherlands. Both sites were built on a sandy soil.&nbsp;</span></p> <p><span>For every variety, cores of the top 20 cm of the soil including aboveground biomass were taken with a core sampler (diameter 28 mm). The core was immediately divided into 4 distinctive layers, thatch + aboveground biomass, mat, remaining upper 10 cm soil and 10-20 cm soil. Distinction of these layers followed the protocol of Evers et al. (2024). </span><span>Aboveground biomass was separated from the thatch with scissors. Sediment from thatch, mat, remaining upper 10 cm of soil and 10-20 cm soil was carefully washed out with tap water, after which the remaining below-ground (dead and living) visible plant biomass and aboveground biomass was dried at 65 &deg;C until stable weight and weighed. Total C and N analyses were carried out with a Vario Micro Cube Element Analyzer (Elementar, Langenselbold, Germany), from which C and N concentrations (in % of dry matter of plant biomass) and C to N ratios (CN ratio) were calculated.</span></p>