Premium
Tillage and Field Scale Controls on Greenhouse Gas Emissions
Author(s) -
Lee Juhwan,
Six Johan,
King Amy P.,
Kessel Chris,
Rolston Dennis E.
Publication year - 2006
Publication title -
journal of environmental quality
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.888
H-Index - 171
eISSN - 1537-2537
pISSN - 0047-2425
DOI - 10.2134/jeq2005.0337
Subject(s) - greenhouse gas , environmental science , scale (ratio) , tillage , field (mathematics) , environmental engineering , agronomy , geography , geology , mathematics , oceanography , cartography , pure mathematics , biology
There is a lack of understanding of how associations among soil properties and management‐induced changes control the variability of greenhouse gas (GHG) emissions from soil. We performed a laboratory investigation to quantify relationships between GHG emissions and soil indicators in an irrigated agricultural field under standard tillage (ST) and a field recently converted (2 yr) to no‐tillage (NT). Soil cores (15‐cm depth) were incubated at 25°C at field moisture content and 75% water holding capacity. Principal component analysis (PCA) identified that most of the variation of the measured soil properties was related to differences in soil C and N and soil water conditions under ST, but soil texture and bulk density under NT. This trend became more apparent after irrigation. However, principal component regression (PCR) suggested that soil physical properties or total C and N were less important in controlling GHG emissions across tillage systems. The CO 2 flux was more strongly determined by microbial biomass under ST and inorganic N content under NT than soil physical properties. Similarly, N 2 O and CH 4 fluxes were predominantly controlled by NO 3 − content and labile C and N availability in both ST and NT soils at field moisture content, and NH 4 + content after irrigation. Our study indicates that the field‐scale variability of GHG emissions is controlled primarily by biochemical parameters rather than physical parameters. Differences in the availability and type of C and N sources for microbial activity as affected by tillage and irrigation develop different levels and combinations of field‐scale controls on GHG emissions.