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 Web of Science Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Web of Science (6) Citing Articles via Google Scholar Google Scholar Articles by Ray, J. D. Articles by Fritschi, F. B. Search for Related Content PubMed Articles by Ray, J. D. Articles by Fritschi, F. B. Agricola Articles by Ray, J. D. Articles by Fritschi, F. B. Related Collections Soybean Crop Growth and Development Crop Physiology & Metabolism

CROP PHYSIOLOGY & METABOLISM

Influence of Large Amounts of Nitrogen on Nonirrigated and Irrigated Soybean

^a Research Geneticist
^b Research Agronomist
^c Research Physiologist, USDA-ARS, Crop Genetics and Production Research Unit, P.O. Box 345, Stoneville, MS (662-686-3036).

^* Corresponding author (jray{at}ars.usda.gov)

Nitrogen supplied by N₂ fixation to soybean [Glycine max (L.) Merr.] may not be sufficient to maximize yield. Field studies were conducted in 2002, 2003, and 2004 on Sharkey clay soil (very-fine, smectitic, thermic Chromic Epiaquert) at Stoneville, MS (33°26' N lat). The objective was to determine the effect of high rates of N applied as a replacement for N₂ fixation in nonirrigated and irrigated environments. Eight cultivars ranging from Maturity Group II to IV were planted on 17 Apr. 2002, 2 Apr. 2003, and 25 Mar. 2004. Not all cultivars were evaluated in all 3 yr. Glyphosate herbicide was used in all 3 yr and a non-glyphosate herbicide treatment was applied in 2002. Cultivars grown in 2003 were also evaluated under an application of 21.3 kg ha^–1 of Mn. All cultivar, herbicide, and Mn treatments were evaluated in irrigated and nonirrigated environments with fertilizer N (PlusN treatment) or without fertilizer N (ZeroN treatment). In the PlusN treatment, granular NH₄NO₃ was surface applied at soybean emergence at rates of 290 kg ha^–1 in 2002, 310 kg ha^–1 in 2003, and 360 kg ha^–1 in 2004. When analyzed over all management practices (years, cultivars, herbicide, and Mn treatments), the PlusN treatment resulted in significantly decreased ureide concentration (57.2 and 53.5% reduction) and significantly increased biomass accumulation (14.1 and 16.7%), N accumulation (12.8 and 28.1%), and seed yield (7.7 and 15.5%) for the irrigated and nonirrigated environments, respectively. The majority of the yield increase in each environment resulted from increased number of seed (9.5% irrigated and 16.2% nonirrigated). These results confirm the sensitivity of N₂ fixation to drought and indicate that N₂ fixation may limit yield of soybean grown in both irrigated and nonirrigated environments of the midsouthern USA, and that N₂ fixation deficiencies occur before the beginning of processes that determine number of seed.

Abbreviations: DAP, days after planting • DTM, days to maturity • ESPS, early soybean production system • MG, maturity group

This article has been cited by other articles:

				F. Salvagiotti, J. E. Specht, K. G. Cassman, D. T. Walters, A. Weiss, and A. Dobermann Growth and Nitrogen Fixation in High-Yielding Soybean: Impact of Nitrogen Fertilization Agron. J., July 7, 2009; 101(4): 958 - 970. [Abstract] [Full Text] [PDF]