Premium
Agronomic Investigations Using Continuous Function Experimental Designs—Nitrogen Fertilization of Sweet Corn 1
Author(s) -
Fox R. L.
Publication year - 1973
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/agronj1973.00021962006500030029x
Subject(s) - human fertilization , mathematics , zea mays , yield (engineering) , nitrogen fertilizer , nitrogen , agronomy , row , field experiment , fertilizer , chemistry , biology , statistics , physics , computer science , organic chemistry , database , thermodynamics
Simple experimental designs are needed for exploratory field studies and for generating data for well defined yield response curves and surfaces. A design was developed by which a variable was increased in many small increments along corn ( Zea mays L.) rows. Individual plants were handled as plots. Sweet corn was grown in rows 12 m long, along which rates of N fertilization increased in 40 increments from 0 to 220 kg/ha. Replication was obtained by repeating the layout but rotating it through 180 degrees. “Border effects” along the row could be ignored because the incremental change of applied N was very small and because the N rate increased in one direction and decreased in the other. Because there are many experimental points it was possible to show that low rates of N produced a “diluting effect” on leaf N, that N deficiency symptoms disappeared and second ear develop ment began at about 140 kg N/ha, that lower corn leaves are the most sensitive indicators of the N status of corn, and that yield response to applied N was linear to 200 kg/ha of N applied. If a second factor is varied at right angles to the first, a well defined response surface can be obtained.