HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Figures Only Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Al-Kaisi, M. M. Articles by Sawyer, J. E. Search for Related Content PubMed Articles by Al-Kaisi, M. M. Articles by Sawyer, J. E. Agricola Articles by Al-Kaisi, M. M. Articles by Sawyer, J. E. Related Collections Nitrogen Carbon Sequestration Crop Systems Soil Fertility and Productivity

TECHNICAL REPORTS

Effect of Nitrogen Fertilizer Application on Growing Season Soil Carbon Dioxide Emission in a Corn–Soybean Rotation

Dep. of Agronomy, Iowa State Univ., Ames, IA 50011-1010. M.L. Kruse, formerly graduate student

^* Corresponding author (malkaisi{at}iastate.edu).

Received for publication May 14, 2007. Nitrogen application can have a significant effect on soil carbon (C) pools, plant biomass production, and microbial biomass C processing. The focus of this study was to investigate the short-term effect of N fertilization on soil CO₂ emission and microbial biomass C. The study was conducted from 2001 to 2003 at four field sites in Iowa representing major soil associations and with a corn (Zea mays L.)–soybean (Glycine max L. Merr.) rotation. The experimental design was a randomized complete block with four replications of four N rates (0, 90, 180, and 225 kg ha^–1). In the corn year, season-long cumulative soil CO₂ emission was greatest with the zero N application. There was no effect of N applied in the prior year on CO₂ emission in the soybean year, except at one of three sites, where greater applied N decreased CO₂ emission. Soil microbial biomass C (MBC) and net mineralization in soil collected during the corn year was not significantly increased with increase in N rate in two out of three sites. At all sites, soil CO₂ emission from aerobically incubated soil showed a more consistent declining trend with increase in N rate than found in the field. Nitrogen fertilization of corn reduced the soil CO₂ emission rate and seasonal cumulative loss in two out of three sites, and increased MBC at only one site with the highest N rate. Nitrogen application resulted in a reduction of both emission rate and season-long cumulative emission of CO₂–C from soil.

Abbreviations: CO₂, carbon dioxide • MBC, microbial biomass carbon • V6, sixth-leaf stage of corn