Relay Intercropping Wheat and Soybean

Relay intercropping is defined as growing two or more crops simultaneously during part of the life cycle of each (Andrews and Kassam, 1976). That is contrasted to the practice of sole cropping where most midwest farmers plant one crop per field per season. In other words, corn is planted in May and harvested in October. Why would farmers be interested in trying relay intercropping when they are already acquainted and efficient in sole cropping systems? The answer is the potential to increase total production per unit area of land during one cropping season and the potential to conserve soil from wind and water erosion during the winter and spring months each year (Chan et al., 1980). How does the relay intercropping system work? First, the farmer would plant winter wheat in September, the normal time for planting winter wheat. The winter wheat will normally head in mid-May and mature in early July. Soybean would be interseeded between the rows of wheat at the normal soybean planting time of early May, just prior to heading of the wheat. Soybean and wheat will compete from May until July. After wheat harvest the soybean will not have further competition until harvest in October.