In the spring of 1993, 210 lbs available nitrogen/A was applied for corn
production. Forty six lbs/A were credited from manure and whey and 164 lbs available
N from anhydrous ammonia. A nitrogen inhibitor was not used. When the wells were
sampled on 3/23/93, two of the 6 wells (wells 3 and 4) had a very strong odor (like sour
milk), and a pale yellow color. Whey permeate had been applied to this field prior to
this date and must have leached very rapidly to the groundwater near these wells during
the spring thaw/recharge. Chloride concentrations increased approximately 200 ppm and
nitrate concentrations were 0.05 ppm in each well while ammonium was 11.4 and 12.1
ppm and organic nitrogen was 20 and 20.5 ppm. There was no odor or color difference
in the other 4 wells and nitrate concentrations ranged from 14.9-25.6 ppm while
ammonium and organic nitrogen were usually less than 1 ppm each.
Another round of samples were taken two months later (5/20/93) and although
chloride concentrations decreased 150-200 ppm in the sour smelling wells, nitrate
concentrations remained about the same. Several months later ('8/19/93), the impact
from the whey permeate on the 2 monitoring wells was diminishing but still apparent.
Nitrate concentrations at these 2 wells were < 5ppm while 3 of the other 4 wells were
above 15 ppm. The 1993 growing season was the year of the floods and rainfall amounts
far exceeded normal (Table 3). Irrigation was not necessary as rainfall events provided
more than enough water for crop growth.

Corn yields for this year were well below the expected yield goal. Harvests were