Another wet spring hit Iowa this year. From mid-April to mid-May northwestern Iowa had about 90 percent of normal precipitation, whereas areas of northeastern Iowa received more than 200 percent of normal. Heavy spring rains, recharged subsoils, a high percentage of fall-applied nitrogen (N), and a warm fall have many producers wondering if this is a scenario for repeating last year's N losses. The ponded areas have mostly dried up, but the question is, "Will the effects of that water appear as N deficiency later in the corn growing season?"One difference so far this year is that the excess rain occurred early in the spring. If heavy rains return, June will be a critical period to watch for N losses.
Available at: http://works.bepress.com/john-sawyer/111/