Soil surface carbon dioxide fluxes induced by spring, summer, and fall moldboard plowing in a sandy loam

• Published in: Soil Science Society of America journal Vol. 63; no. 3; pp. 621 - 628
• Main Authors: Rochette, P, Angers, D.A
• Format: Journal Article
• Language: English
• Published: Madison, WI Soil Science Society of America 01.05.1999; American Society of Agronomy
• Subjects: Agronomy. Soil science and plant productions; autumn; Biological and medical sciences; Carbon dioxide; Carbon dioxide emissions; Chemical, physicochemical, biochemical and biological properties; crop residues; Cropping systems. Cultivation. Soil tillage; Decomposition; degradation; Earth sciences; Earth, ocean, space; emissions; Environmental monitoring; Exact sciences and technology; Fundamental and applied biological sciences. Psychology; General agronomy. Plant production; incorporation; losses from soil; microclimate; Organic chemistry; Organic matter; Physics, chemistry, biochemistry and biology of agricultural and forest soils; Plowing; Sandy loam; sandy loam soils; Sandy soils; Seasons; Soil organic matter; Soil science; Soil surfaces; soil temperature; Soil tillage; Soils; Spring; Summer; Surficial geology; Tillage; Tillage. Tending. Growth control; Quebec; Canada; North America; America; Monocotyledones; Organic matter; Gas emission; Cultivated soil; Carbon dioxide; Environmental factor; Summer; Decomposition; Temperate zone; Cereal crop; Field experiment; Plowing; Degassing; Organic matter cycle; Gramineae; Ground surface; Seasonal variation; Spring(season); Angiospermae; Oxidative degradation; Moldboard plowing; Sandy loam soil; Cultural practice; Soil tillage; Zea mays; Autumn; Application time; Soil management; Vegetal waste; Carbon cycle; Spermatophyta; Mass flow
• ISSN: 0361-5995; 1435-0661
• DOI: 10.2136/sssaj1999.03615995006300030027x

Soil tillage is believed to influence soil organic matter decomposition. We hypothesized that the short-term impacts of tillage on soil surface CO(2) emissions would vary following spring, summer, and fall moldboard plowing of a sandy loam (loamy, mixed, frigid Umbric Dystrochrept). At all dates, plowing increased CO(2) emissions by 7 to 20 micromol m(-2) s(-1) during the first hours following tillage due to degassing of soil CO(2). The effects of tillage following this initial burst varied with date of plowing. Fall incorporation of fresh maize residues increased CO(2) losses by 173 kg C ha(-1) during a period of 4 d compared with a non-tilled control, until halted by a sudden drop of 6 degrees C in soil temperature with the onset of winter. In contrast, the cumulative CO(2) fluxes following spring plowing of fall-applied residues were 186 kg C ha(-1) lower than on a non-tilled control. This effect of spring plowing on CO(2) fluxes lasted for 2 wk, during which soil temperatures in the plow layer were below 10 degrees C. Summer plowing increased CO(2) emissions by as much as 2 micromol m(-2) s(-1) for a period of 65 d, resulting in cumulative soil C losses of 685 kg C ha(-1) compared with the undisturbed control. Variations in tillage-induced CO(2) emissions between dates were attributed to differences in soil microclimatic conditions following plowing events. The study of the impact of tillage on soil organic matter decomposition should consider the time of year when the soil is tilled.