RESPONSE OF IRRIGATED FIELD AND SWEET CORN TO NITROGEN AND PHOSPHORUS FERTILIZERS IN SOUTHERN ALBERTA

Abstract

A two-dimensional systematic design provided a precise assessment of the response of field and sweet corn (Zea mays L. cv. UH 106 and Yukon) to a wide range of fertilizer N and P levels. Both cultivars responded primarily to N, with only limited responses to P. Yield increased significantly with incremental N levels up to 100 kg/ha and slightly with increments of N up to 200 kg/ha. Total dry matter yields responded to higher levels of N than did grain yield, and field corn was more responsive to N fertilizer than was sweet corn. Yields were significantly lower with no P than with P fertilizer levels of 15 kg/ha or higher. The limited response to P was probably due to the moderate to high levels of residual fertilizer P in the soil.