Having more outside edges in the field raises yields. This fall, a few outside rows' weigh-wagon yields were over 400 bu./acre, and several strips averaged over 300 bu./acre. Several test sites averaged as high as 280 bu./acre (all the rows).
Mike and Herb Recker, Dyersville, IA, have hosted several strip test plots, including the photo above in this sequence. Their average strip intercropping corn yield is 278 bu./acre with 30-in. rows and 6-row strips. The Reckers used variable-rate planting at 62,000, 50,000 and 34,000 seeds/acre, with outside rows having the highest populations to take advantage of the extra sunlight they receive.
This is “sprocketologist” Bob Recker, Cedar Valley Innovation founder, Waterloo, IA. He uses off-the-shelf parts to configure alternate-rate driver shafts to plant the two outer (corn) strips at 62,000/acre; the next two at 50,000/acre; and the “inside” two 34,000/acre, he leverages the edge effect. But variable-rate planting is not mandatory to realize the “strip advantage,” he says.
“The most capital-efficient profits originate from multiplying yields on existing ground, rather than adding new acres to cover," says strip intercropper Ben Witte, Fairbank, IA. And some say that soybeans grown as part of strip intercropping systems suffer soybean yield hits of 10-15%, although a number of strip intercroppers have overcome that. Witte has average bean yields in his strips of 56.7 bu. by using a proven Group 3.1 disease-tolerant, fungicide- and insecticide-treated variety, planted at 152,000/acre.
Conservation strips with grass and organic corn anchors soil and is another way to strip-intercrop. Some are experimenting with high-value crops.
Corn and soybean strips in Dyersville, IA.This farm has tested strip intercropping for three years. Alternating six-row strips of corn/beans, they gained an average of 40 bu./acre on their corn, with “edge-row” corn yields as high as 325 bu./acre on ground “that has to stretch to reach 200 in monocrop,” Bob Recker says. This farm bumped plant populations on the outside corn row to 62,000/acre. The second row in from the edge is planted at 52,000, and the third row is at 36,000.
Jacob Bolson and Roger Knutson, Hudson, IA. Roger's strip-corn yield averaged 230 bu./acre using 36-in. rows and 4-row strips. Variable-rate planting was used at 60,000 and 32,000 seeds/acre.
Jacob Bolson and Bob Recker, Hubbard, IA
Looking at each plant's yield potential is what strips are all about. Some call it a Japanese approach to space, or a new level of zoom, because each plant's spacing, light reception and yield potential is studied.
Marc Burggraff, Flandreau, SD, has seen up to a 100-bu./acre difference between the outside corn row (of six-row corn strips) and the middle corn row of his strips. He tested both 12-row and six-row strips of corn/soybeans in 2010. “My six-row corn strips averaged 235 bu./acre, with two of them going over 250 bu./acre. This is amazing since our county average is in the 160s,” he says.
Yield by row in a 20-ft. strip.
Corn and Soybean Digest