Page Banner

United States Department of Agriculture

Agricultural Research Service

Research Project: ECOLOGICALLY-SOUND PEST, WATER AND SOIL MANAGEMENT STRATEGIES FOR NORTHERN GREAT PLAINS CROPPING SYSTEMS Title: Residue placement and rate, crop species, and nitrogen fertilization effects on soil greenhouse gas emissions

Authors
item Wang, Jun -
item Sainju, Upendra
item Barsotti, Joy

Submitted to: Agronomy Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: June 19, 2012
Publication Date: November 17, 2012
Repository URL: http://handle.nal.usda.gov/10113/57684
Citation: Wang, J., Sainju, U.M., Barsotti, J.L. 2012. Residue placement and rate, crop species, and nitrogen fertilization effects on soil greenhouse gas emissions. Agronomy Journal. 3(10):1238-1250.

Interpretive Summary: High temporal and spatial variability in the measurement of greenhouse gas (GHG) fluxes at the field scale often mask differences among treatments. Variability exists not only due to diurnal and seasonal changes in soil temperature and water content but also to perturbations (e.g. tillage, fertilization, precipitation events, and thawing). Information is needed on the effect of management practices on GHG emissions under these conditions. We examined the effect of management practices on CO2, N2O, and CH4 fluxes and soil temperature and water content from July to November, 2012 in a greenhouse. Treatments were incomplete combinations of residue placement (surface placement vs. incorporation into the soil) and rates (0.25 and 0.50%), crop species (spring wheat, pea, and fallow), and N fertilization rates (0.11 and 0.96 g N pot-1). Soil temperature was not influenced by treatments but water content was greater under fallow with surface residue than in other treatments. The GHG fluxes peaked immediately following water application and/or N fertilization, with coefficient of variation (CV) ranging from 21 to 46%, <50% of that reported in the field. Average CO2 and N2O fluxes were greater under wheat or fallow with surface residue and 0.96 g N pot-1 than in other treatments. Average CH4 uptake was greater under fallow with surface or incorporated residue and 0.11 g N pot-1 than in other treatments. Doubling the residue rate increased CO2 flux by 9%. Greater root respiration, N substrate availability, and soil water content increased CO2 and N2O emissions under wheat or fallow with surface residue and high N rate but fallow with low N rate increased CH4 uptake. Controlled soil and environmental conditions substantially reduced variations in GHG fluxes.

Technical Abstract: High variability due to soil heterogeneity and climatic conditions challenge measurement of greenhouse gas (GHG) emissions as influenced by management practices in the field. To reduce this variability, we examined the effect of management practices on CO2, N2O, and CH4 fluxes and soil temperature and water content from July to November, 2012 in a greenhouse. Treatments were incomplete combinations of residue placement (surface placement vs. incorporation into the soil) and rates (0.25 and 0.50%), crop species (spring wheat [Triticum aestivum L.], pea [Pisum sativum L.], and fallow), and N fertilization rates (0.11 and 0.96 g N pot-1). Soil temperature was not influenced by treatments but water content was greater under fallow with surface residue than in other treatments. The GHG fluxes peaked immediately following water application and/or N fertilization, with coefficient of variation (CV) ranging from 21 to 46%, <50% of that reported in the field. Average CO2 and N2O fluxes were greater under wheat or fallow with surface residue and 0.96 g N pot-1 than in other treatments. Average CH4 uptake was greater under fallow with surface or incorporated residue and 0.11 g N pot-1 than in other treatments. Doubling the residue rate increased CO2 flux by 9%. Greater root respiration, N substrate availability, and soil water content increased CO2 and N2O emissions under wheat or fallow with surface residue and high N rate but fallow with low N rate increased CH4 uptake. Controlled soil and environmental conditions substantially reduced variations in GHG fluxes.

Last Modified: 10/22/2014
Footer Content Back to Top of Page