Nitrogen Distribution, Yield, and Quality of Silage Corn after Foliar Nitrogen Fertilization

Abstract

AbstractForage corn (Zea mays L.) is an important crop because of its high energy content; however, an improvement in the protein quality of forage corn would be desirable. In some instances foliar N fertilization has resulted in improved yield of corn. The objective of the study was to determine the effects of foliar applied N on yields and on forage protein quality. Foliar urea spray (20 kg urea N ha−1) was applied to DeKalb W‐844 corn at two growth stages: 10% silking and 4 wk after the 10% silking stage. The field experiment was carried out on a Ste‐Rosalie clay (very fine silty, mixed, non‐acid, mesic) and an Ormstown silty clay (fine silty, mixed, non‐acid,mesic), both Typic Humaquepts, in the 1984 and 1985 growing seasons. Applied urea Was not detectable on the leaf surface of the plants by the third day following spraying. A transitory increase in the urea‐N and nonprotein N contents was observed 1 d after the spray. By the third day following the spray, there was no difference in the urea‐N and nonprotein N contents of sprayed and non‐sprayed plants. The effects of the foliar sprays on whole‐plant yield, grain yield, and protein quality of corn silage were not consistent. In general, the second spray resulted in increased protein yields. The results suggest that, although the foliar‐applied urea was absorbed by the corn plants in all cases, its effect on yields and protein quality of the corn silage was variable.