Note to readers, attached is the complete final report for FNE96-128
Mr. Groff conducted an experiment to determine whether he could reduce his need for herbicide by spacing his corn rows closer together, and so crowding out the weeds. He planted three plots of corn with the rows spaced 15 inches apart, and three more at the more traditional spacing of 30 inches. He used approximately the same planting density, about 30 000 seeds per acre, on all plots. He reported that by harvest time one weed in particular– fall panicum– was visibly less dense in the plots of narrow-spaced corn. Yield in the narrow-spaced plots averaged 153 bushels per acre, while 30-inch spacing gave an average of 139 bushels per acre, viz. an increase of about 10% for narrow spacing. After allowing for the slightly higher costs occasioned by narrow spacing, Mr. Groff figured this translated into an additional profit of $31.74 per acre over and above what he realized from the 30-inch plots.
The following spring Mr. Groff observed that residue still covered 85% of the ground where the 15-inch rows had been, while only 76% of the ground was covered where the 30-inch rows had been. He believes the 15-inch rows should consequently provide appreciably better protection against erosion on sloping ground.