THE EFFECT OF DRAINAGE, ROTATION AND FERTILIZER ON CORN YIELD, PLANT HEIGHT, LEAF NUTRIENT COMPOSITION AND PHYSICAL PROPERTIES OF BROOKSTON CLAY SOIL IN SOUTHWESTERN ONTARIO

Abstract

Yield of corn on Brookston clay increased 0.45 t∙ha−1∙yr−1 as distance from subsurface drain was reduced by 2 m (2.5 vs. 0.5 m). Yield increases associated with this drain-spacing interval were significant [Formula: see text] in eight of the individual years 1971–1980. While drain spacing affected yield and plant height, it had little effect on plant leaf percent NPK, soil porosity and compaction. Variation in soil measurements appeared to be primarily due to climate and rotation. Analysis of the yield data suggests that the effects of soil drainage, crop rotation and use of fertilizer are primarily additive, and that each of these practices is essential to achieving high yields of corn on southwestern Ontario clay soils. The response of rotation corn to applied fertilizer was lower than that of continuous corn, indicating that adjustment of N application in accordance with cropping history of soil may be cost effective.