Grain Yields and Land Equivalent Ratios from Intercropping Corn and Soybeans in Minnesota 1

Intercropping, or growing two or more crops simultaneously on the same field, is a farming practice that has recently received attention from agronomic scientists as a means of improving land usage. The objective of this study was to determine whether present‐day corn ( Zea mays L.) hybrids intercropped with soybean ( Glycine max L. Merrill) at conventional row spacings would increase land usage in Minnesota. Two different intercropping patterns were examined, each under three environments. The first pattern consisted of growing the two crops in combinations of alternating 76‐cm spaced rows. The patterns were: single alternate rows, three rows of each crop alternated, six rows of each crop alternated, and twelve rows of each crop alternated. Both crops were planted on the same day. In the second pattern, the two crops were grown in single, alternating, 38‐cm rows, with corn maturity rating, population, and planting date as variables Although corn yields were significantly improved in some combinations of the first pattern, accompanying soybean yields were always reduced to the extent that none of the combinations made significantly different use of the land than did sole cropping. In many combinations of the second pattern, both corn and soybean yields decreased and land usage was thereby significantly reduced. In the other combinations of the second pattern land usage was unaffected. Minnesota land use efficiency was thus not improved by intercropping corn and soybeans in a variety of management combinations. Management approaches that might be expected to result in improved land usage are postulated.