Ralph “Junior” Upton (Springerton, IL) began using cover crops (buckwheat and hairy vetch) in the 1980s, mainly to reduce erosion on his hilly acres. In the 90s, he began looking for a cover crop to break up the hardpan soil just below plow depth. “I haven’t got the best soil, so I’ve always been tinkering with how to improve my yield, especially in dry years,” he said.
Working closely with Mike Plumer (a farmer and Univ. IL Extension educator at the time), Upton was among a half dozen Midwest producers who tried annual ryegrass on small plots, planted in the fall after harvest. “I rely on Mike for knowing what to look for in the soil. When I called him out that next April, we were all surprised to find ryegrass roots to 72 inches, with a top growth of only 4 inches,” Upton said. “I had always thought that you only get an inch of roots for every inch of top growth.”
Later that summer, after having killed the ryegrass and then planted corn, he went back to the same field location to see whether the deep ryegrass roots might have impacted the growth of corn roots. “The annual ryegrass opened up small channels that corn roots used to access deeper soil and moisture,” Upton said. Deep rooting has allowed his corn and bean crops to do better in dry years, because the cover crop also took care of the hardpan soil. “There was no longer any restriction to growth,” he added.
This year, having gotten only one rainfall when the corn was knee high, his crop was not as productive as in normal years. Still, with some farmers in his area mowing down their entire acreage, Upton was happy getting an average of 70 bu/ac. and a high of about 130 bu/ac. With temperatures above 100 degrees for weeks, many saw their corn fail to pollinate. Upton wonders whether pollination, in addition to deeper rooting (soil was bone dry to 3 feet), could be impacted by the presence of annual ryegrass.