Greenhouse gas fluxes in varying soils types under conventional and no-tillage practices

Consideration of the environmental effects of the no-tillage practice should be made on the basis of its effects on both carbon and nitrogen cycles. There is a lack of data on the effects of the no-till management in the cool and humid climate and typical soil types of Northern Europe. We measured the fluxes of nitrous oxide (N2O), carbon dioxide (CO2) and methane (CH4) on conventionally ploughed agricultural soils and on respective soils that had been under no-till practice for 5–7 years. Ten chamber measurement investigations were carried out during a 10-month period on six pairs of tilled and no-till fields on clayey (Vertic Cambisols, three pairs), coarse (Eutric Regosols, two pairs), and organic (Dystric Histosols, one pair) soils located between latitudes 60° and 62° N. The results suggest that there is a risk of increased N2O emissions in the first years of no-till practice under small grain spring cereal cultivation in Northern European boreal climate. Carbon dioxide emissions measured as total ecosystem respiration were either unchanged, increased or decreased under no-till. Fluxes of CH4 were negligible and not affected by no-till practice. Dry bulk density and soil moisture were higher in no-till soils compared to annually mouldboard ploughed soils. Variation in the greenhouse gas fluxes was best explained by the content of carbon and nitrogen in the topsoil of 0–20 cm.