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

This Article Figures Only Full Text Free Full Text (PDF) Free Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in ISI Web of Science Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via ISI Web of Science (1) Citing Articles via Google Scholar Google Scholar Articles by Adamsen, F. J. Articles by Leavitt, S. W. Search for Related Content PubMed Articles by Adamsen, F. J. Articles by Leavitt, S. W. Agricola Articles by Adamsen, F. J. Articles by Leavitt, S. W. Related Collections Nitrogen Global Change Wheat Nutrient Management

Nutrient Uptake

Temporal Changes in Soil and Biomass Nitrogen for Irrigated Wheat Grown under Free-Air Carbon Dioxide Enrichment (FACE)

^a USDA-ARS, U.S. Water Conservation Lab., 4331 E. Broadway Road, Phoenix, AZ 85040
^b Humbolt Univ. of Berlin, Dep. of Soil Science, Invalidenstrasse 42, 10115 Berlin, Germany
^c Potsdam Institute for Climate Impact Research, Natural Systems Dep., P.O. Box 601203, 14412 Potsdam, Germany
^d LI-COR, 4421 Superior St., Lincoln, NE 68504
^e Lab. of Tree Ring Res., Univ. of Arizona, Tucson, AZ 85721

^* Corresponding author (fadamsen{at}uswcl.ars.ag.gov)

Received for publication December 30, 2003. Increasing atmospheric CO₂ concentrations are expected to increase plant production and demand for N and other nutrients. The objectives of this investigation were to characterize and quantify the temporal trends in soil mineral N and aboveground biomass N during the growing season of wheat (Triticum aestivum L.) with adequate N, ambient and elevated CO₂, and two levels of water stress. The free-air CO₂ enrichment (FACE) technique was used to enrich the air from 370 to 550 µmol mol^–1 CO₂. Spring wheat was planted in late December of 1992 and 1993 and harvested at the end of May. Each main plot (CO₂ level) was split into two irrigation treatments to replace 100 and 50% of the potential evapotranspiration. Soil and plant samples were taken for N analysis six times each year. Elevated CO₂ lowered soil mineral N concentrations in the top 0.3 m of soil as much as 40% and increased aboveground biomass N by as much as 16% compared with the ambient treatment. Before anthesis, irrigation level had little effect on either soil mineral N or aboveground biomass N, but at harvest in 1992–1993 and at dough stage in 1993–1994 deficit-irrigated plots had higher soil mineral N (p < 0.05) and lower aboveground biomass N than plots that received adequate irrigation. There was little variation in the concentrations of N in the aboveground biomass among treatments within a sampling date. The data suggest elevated CO₂ may lead to rapid N uptake, which could result in increased early vegetative growth.

Abbreviations: DOY, day of year • Dry, water-stress treatment • FACE, free-air carbon dioxide enrichment • GLM, General Linear Model Procedure • MAC, University of Arizona Maricopa Agricultural Center • Wet, well-watered irrigation treatment