effect of reduced tillage agriculture on carbon dynamics in silt loam soils

• Published in: Nutrient cycling in agroecosystems 2009-07, Vol.84 (3), p.249-265
• Main Authors: D'Haene, Karoline, Sleutel, Steven, De Neve, Stefaan, Gabriels, Donald, Hofman, Georges
• Format: Article
• Language: English
• Subjects: Agricultural practices; Agricultural research; Agriculture; biogeochemical cycles; Biomedical and Life Sciences; Carbon; conventional tillage; crop management; Crop rotation; erodibility; Life Sciences; Loam soils; long term experiments; losses from soil; Microorganisms; Mineralization; Organic carbon; Organic soils; plowing; reduced tillage; Research Article; root crops; Silt loam; silt loam soils; soil depth; Soil dynamics; Soil erosion; Soil layers; soil microorganisms; soil organic carbon; Soil profiles; Soil properties; Soil types; spatial distribution; spatial variation; Stratification; temporal variation; Tillage
• ISSN: 1385-1314; 1573-0867
• DOI: 10.1007/s10705-008-9240-9

Reduced tillage (RT) agriculture is an effective measure to reduce soil loss from soils susceptible to erosion in the short-term and is claimed to increase the soil organic carbon (SOC) stock. The change in distribution and total SOC stock in the 0-60 cm layer, the stratification of microbial biomass carbon (MB-C) content in the 0-40 cm layer and the carbon (C) mineralization in the upper 0-5 cm layer in silt loam soils in Western Europe with different periods of RT agriculture were evaluated. Ten fields at seven locations, representing the important RT types and maintained for a different number of years, and eight fields under conventional tillage (CT) agriculture with similar soil type and crop rotation were selected. RT agriculture resulted in a higher stratification of SOC in the soil profile than CT agriculture. However, the total SOC stock in the 0-60 cm layer was not changed, even after 20 of years RT agriculture. The MB-C was significantly higher in the 0-10 cm layer under RT agriculture, even after only 5 years, compared to CT agriculture. The higher SOC and MB-C content in the upper 0-5 cm layer of RT fields resulted in a higher C mineralization rate in undisturbed soil in the laboratory. Simulating ploughing by disturbing the soil resulted in inconsistent changes (both lower and higher) of C mineralization rates. A crop rotation with root crops, with heavy soil disturbance every 2 or 3 years at harvest, possibly limited the anticipated positive effect of RT agriculture in our research.