Submitted to: Agronomy Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: June 20, 1994
Publication Date: N/A
Technical Abstract: Field studies have been conducted over five years to evaluate the utilization of nitrogen following alfalfa by corn seeded with and without tillage at different dates for both killing the alfalfa and seeding the corn. Results indicate that the mineralization rate for nitrogen fixed while the alfalfa was growing varies from year to year as does the amount of nitrate-N accumulated in noncropped plots, the latter reaching values as high as 614 kg ha-1 in the top 150 cm of soil. Most years the nitrate-N was below 100 kg ha-1 in cropped plots at the time of corn harvest, but values did exceed 100 kg ha-1 at times during the growing season. Nitrogen uptake by the corn ranged from 158 to 192 kg ha-1. Generally, waiting as late as possible in the spring to kill the alfalfa and seed the corn is a good practice to obtain the best utilization of nitrogen.