Premium
Effect of Fertilization Method and Tillage on Nitrogen‐15 Recovery by Corn
Author(s) -
Timmons D. R.,
Cruse R. M.
Publication year - 1990
Publication title -
agronomy journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.752
H-Index - 131
eISSN - 1435-0645
pISSN - 0002-1962
DOI - 10.2134/agronj1990.00021962008200040025x
Subject(s) - tillage , plough , stover , agronomy , sowing , fertilizer , human fertilization , ammonium nitrate , growing season , nitrogen , zoology , chemistry , biology , crop , organic chemistry
Fertilizer N utilization by corn ( Zea mays L.) is influenced by different fertilizer management and tillage systems. A study was conducted in central Iowa during two consecutive years to evaluate the uptake and recovery of labeled N for continuous corn grown in two tillage systems with two fertilization methods. Tillage systems were fall moldboard‐plow and ridge‐till. Labeled N (5% 15 N) as 28% urea‐ammonium nitrate solution (UAN) was either surface‐applied in the fall before any primary tillage or banded (knifed‐in) between rows at 224 kg N ha −1 just before planting. Depending on tillage and fertilization method, corn grain yields ranged from 1.3 to 7.3 Mg ha −1 which were below normal due to adverse weather conditions during the two growing seasons. The percent of plant N derived from labeled N (N f ) in the sixth leaf (50% silk) and in mature grain, stover, and whole plants was significantly lower for fall surfaceapplied 15 N than for spring banded 15 N. For mature whole plants, N r ranged from 9 to 59% and averaged 53% for spring banded and 17% for fall surface‐applied 15 N. Labeled N recovery by mature corn grain was affected by fertilization method and growing season and ranged from 1 to 25% during the 2‐yr period. Labeled N recovery by mature whole plants ranged from 2 to 41% and averaged four times greater for spring banded than for fall surface‐applied 15 N. About 1 yr after application, an average of 20% of the 15 N remained in the soil profile; and 95% of the residual 15 N was found in the organic N pool. Compared with spring banded N, fall surface‐applied N was extremely inefficient for both tillage systems.