Submitted to: Agronomy Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: October 28, 1997
Publication Date: N/A
Technical Abstract: Corn grain response to added nitrogen (N) fertilizer has been proposed to vary within individual fields as well as among different corn producing regions; this needs to be investigated to improve variable-rate N fertilizer recommendations for site-specific crop management. Research was initiated to study corn response functions within various soil and landscape areas of Missouri claypan (three site-years) and alluvial (two site-years) soil fields and to quantify the soil and landscape features that can be used to predict different N response areas. Grain yield response to N fertilizer was significantly different (intercept and slope) between areas of individual fields for most study years. In several cases maximum yields between areas were achieved at about the same N fertilizer rate but maximum yields were significantly different. Relative field elevation, slope, and electromagnetic induction (EM) of the top 1.5 m of soil were measurements found to be useful in identifying different N response function areas.