Download a free copy of the Adobe Acrobat Reader. SRL123 Prepared by Chad M. Roth, James P. Shroyer, and Gary M. Paulsen Grain sorghum contains a number of compounds that suppress other plant species, an effect known as allelopathy. After sorghum is har- vested for grain, the compounds may leach from the residue into the soil and affect the germination, growth, and yield of the following crop.
Wheat often is double-cropped after sorghum in Kansas.
The practice makes efficient use of the land and soil moisture, covers the soil to prevent erosion during winter, and provides income in the following year. However, the wheat may be injured and its yield reduced by allelopathic effects of the sorghum. Injury might be decreased by planting varieties of wheat that are resistant to allelopathy, but none have been identified. Allelopathy also might be reduced by proper management of the sorghum residue. After the toxic compounds leach from the residue, they are degraded into harmless chemicals by microorganisms in the soil.