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Role of Nitrogen Form in Determining Yield of Field‐Grown Maize
Author(s) -
Smiciklas Ken D.,
Below Fred E.
Publication year - 1992
Publication title -
crop science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.76
H-Index - 147
eISSN - 1435-0653
pISSN - 0011-183X
DOI - 10.2135/cropsci1992.0011183x003200050032x
Subject(s) - biology , canopy , dry matter , nitrogen , photosynthesis , agronomy , nutrient , zoology , plant nutrition , horticulture , botany , chemistry , ecology , organic chemistry
Although the maize ( Zea mays L.) plant can utilize either NH 4 −N or NO 3 −N, many hydroponic studies have shown that mixed‐N nutrition (NH 4 + NO 3 ) can optimize growth and yield. Results from field studies have been more erratic, however, and may be influenced by genotype. A 2‐yr field study was therefore conducted at Urbana, IL, to evaluate five maize genotypes (B73 × LH51, LH74 × LH51, LH74 × LH82, LHE136 × LH82, and LHE136 × LH123) for plant growth, nutrient content, grain yield, and canopy photosynthesis (P s ) when N was supplied either as calcium nitrate (NO 3 plots) or urea plus a nitrification inhibitor (mixed‐N plots). Three of the five genotypes (B73 × LH51, LH74 × LH51, and LHE136 × LH82) increased grain yield (by 6∓8%) when supplied with mixed N, compared with plants supplied with predominantly NO 3 . However, NO 3 ‐grown plants had equivalent or greater rates of canopy P s (≈5–10%) than mixed N plants, and the duration of P s was unaffected by N‐form treatment at photosynthetic photon flux densities of 900 or 1800 μmol photon m −2 s −1 . Furthermore, N‐form treatment did not affect the duration of daily canopy P s . Genotypes responsive to mixed N utilized distinct physiological strategies to achieve increased grain yields. For example, the genotype LHE136 × LH82 increased the partitioning of dry matter to the grain, whereas LH74 × LH51 and B73 × LH51 increased total dry matter production. Mixed‐N nutrition decreased the percentage of aborted kernels for the genotype B73 × LH51 and increased anthesis ovule number per earshoot for LH74 × LH82. Plants of the five genotypes supplied with mixed N also increased whole‐shoot N content at maturity (by 5–14%). Based on these data, we conclude that mixed‐N nutrition can moderately increase grain yield and productivity of certain maize genotypes by altering dry matter accumulation and partitioning, earshoot and ovule development, and N accumulation.