Publication date: October 2014
Source:Geoderma, Volumes 230–231
Author(s): P. Prajapati , P.A. Jacinthe
Long-term no-till (NT) farming can improve the methane (CH4 ) oxidation capacity of agricultural soils, but the relative contribution of soil biological and physical properties on this outcome remains unclear. This understanding is especially important in fine-textured and poorly-drained soils where gas transport can limit expression of the potential for biological CH4 oxidation. A study was conducted to assess gaseous diffusivity (Ds ), CH4 oxidation capacity (initial CH4 : ~m , Vmax , Th ) in a well-drained (WD) and a poorly-drained (PD) soil under forest (WL), plow till (PT) and long-term NT (504 oxidation capacity (μg4 -Cm ) and thresholds for CH4 oxidation (Th ) were lower in NT (Km : 100.5; Th : 0.64 m : 134; Th : 2.74 4 in soils under long-term NT. Irrespective of soil drainage, Ds was significantly higher in NT (2.974 oxidation rates in intact soil cores were positively related to Ds (r2 4 oxidation. This limitation was most pronounced in the PD soils under PT (CH4 consumption in cores was only 6% of that in sieved soils); thus, this combination of soil type and tillage would be least favorable to CH4 uptake at the field-scale. Overall these results confirm the positive impact of NT on both the biological and physical soil attributes essential for CH4 uptake in croplands. Long-term implementation of NT farming could therefore contribute to the mitigation of CH4 emission from agriculture.
Source:Geoderma, Volumes 230–231
Author(s): P. Prajapati , P.A. Jacinthe