Strip intercropping effects on yield and yield components of corn, grain sorghum, and soybean

Strip intercropping of corn (Zea mays L.) and soybean [Glycine mar (L.) Mer r.] and grain sorghum [Sorghum bicolor (L.) Moench] and soybean may be a vi able alternative to monoculture cropping to help reduce soil erosion. Caref ul study of yields and yield components can add to understanding crop perfo rmance and contribute to design of more productive systems. Rainfed and irr igated experiments were conducted in eastern Nebraska from 1988 to 1990, on a Sharpsburg silty clay loam (fine, smectitic, mesic Typic Argiudoll), to quantify strip-intercropping effects on crop yields and geld components. Co rn border-row and grain sorghum border-row yields next to soybean increased significantly compared with inside rows in the strips. Increased seed numb er and seed weight contributed to higher corn border-row yields, while only seed number increased in grain sorghum border rows. Soybean border-row yie lds were lower next to all corn strips and nest to grain sorghum strips at the rainfed site. Soybean seed number was lower in border rows next to corn . Corn border-row increases in seed number and seed weight indicate that co mpetition for resources was important in both reproductive and grain-fillin g periods; sorghum border-row increases in seed number suggest competition only in the reproductive period. Higher corn density in border rows mag fur ther exploit a competitive advantage with soybean in the reproductive perio d, perhaps increasing system productivity. Whole-system productivity of str ip-intercropping systems was a maximum of 4% higher than monocultures of co mponent crops, and gross returns did not differ between the two systems. If there is need to control soil erosion, strip intercropping can be equally profitable to monoculture if production costs are similar.