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

This Article 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 Gentry, L. E. Articles by Below, F. E. Search for Related Content PubMed Articles by Gentry, L. E. Articles by Below, F. E. Agricola Articles by Gentry, L. E. Articles by Below, F. E.

Maize Productivity as Influenced by Form and Availability of Nitrogen

Dep. of Agronomy, 1102 S. Goodwin Ave., Univ. of Illinois, Urbana, IL 61801

^* Corresponding author.

Although N, especially mixtures of NO₃ and NH₄, can increase the productivity of maize (Zea mays L.), it is unclear when this N needs to be available for maximum benefit. This study was conducted to determine the importance of preanthesis N form and the need for available postanthesis N on the productivity of maize. Four single-cross hybrids (B73 x LH51, LH74 x LH51, LH74 x LH82, and LHE136 x LH82) were grown in field-hydroponics and supplied N as either all NO₃ or an equal mixture of NO₃ and NH₄ (mixed nutrition) until anthesis, whereupon N was withdrawn from one-half of the plants. At physiological maturity, whole shoots were harvested, separated into component fractions, weighed, and analyzed for yield, yield components, and macronutrient composition. Compared with all NO₃, mixed N nutrition increased grain yield of all hybrids whether the N was available full season (average of II%) or only during vegetative growth (average of 10%). In contrast, regardless of the N form, N deprivation during grain fill decreased grain yield for three of the four hybrids (range of 6 to 19%) but increased yield (5%) for LHE136 x LH82. Changes in sink-source partitioning, kernel number, and plant N accumulation were closely related to both yield enhancement associated with mixed N nutrition, and yield reduction due to N removal. Therefore, these data show that N form, timing of N availability and genotype are all factors that interact to influence N use and productivity of maize.

Received for publication June 8, 1992.