Phosphorus, Lime and Copper Increase Sweet Corn Yields

Soil and plant samples taken from 90 sweet corn fields in the Willamette Valley during 1978 showed low Cu and B levels but responses to applied Cu and B in commercial fields have been inconsistent. Yields and maturity dates of sweet corn in the Willamette Valley are known to respond to banding P fertilizer at planting. The yield response to various rates of banded P in the presence of high P soil test is unknown. High rates of P and Cu may be antagonistic.

Sweet Corn Yield Affected by Timing of Nitrogen Application

Production of commercial nitrogen (N) fertilizers depends on fixing atmospheric N, a process which consumes natural gas. As world energy prices soar, the cost of fertilizer N must also increase, making efficient crop uptake of applied N ever more important. It may be possible to increase the efficiency of crop N utilization by splitting the total crop requirement among two or more applications. In some situations, application of the entire crop N requirement at one time may lead to significant losses to volatilization, leaching, or runoff.

Form and Timing of Applied Nitrogen on Sweet Corn Production (1984)

Recent experiments at the North Willamette Station indicated that, for a given level of N, yields are increased by delaying application of the bulk of the N fertilizer until the corn is 10 to 12 inches tall. These experiments used ammonium nitrate as N source and the late applied N was sidedressed on the soil surface. No additional benefit was obtained by delaying application of a portion of the N until tasseling or silking. The yield increase with split application of N could be from leaching of NO3-N below the root zone when all N is applied at planting.