SOME RELATIONSHIPS BETWEEN SOIL POROSITY, LEAF NUTRIENT COMPOSITION AND YIELD FOR CERTAIN CORN ROTATIONS AT TWO FERTILITY LEVELS ON BROOKSTON CLAY

Abstract

Continuous corn culture was associated with soil compaction in a 13-yr rotation experiment on Brookston clay. Fertilizer application failed to alleviate the detrimental effects of this compaction on K uptake by the plants in comparison with uptake where no fertilizer was applied throughout the experimental period. In addition, the efficiency of N use appeared to be reduced under monoculture conditions. While a rotation of corn with oats or with oats and seedling alfalfa was superior to a continuous corn system, a 4-yr rotation including 2 yr of alfalfa allowed for maximum fertilizer response in yield, adequate plant nutrition and maintenance of favorable soil tilth. For fine-textured soils, the desirability of a rotation system that includes legumes is clearly indicated for corn production.