We evaluated and compared grain yield, available soil water, and water productivity of winter wheat and grain sorghum in two four-​year rotations- wheat-​wheat-​sorghum-​fallow (WWSF) and wheat-​sorghum-​sorghum-​fallow (WSSF)- as well as winter wheat in a continuous winter wheat rotation (WW).

Yield, biomass, water productivity, and soil water were greater for sorghum following wheat as opposed to following sorghum. Wheat following fallow had higher yield, biomass, water productivity, and soil water compared to continuous wheat.

Within the WWSF rotation, the second wheat crop yielded 20% less than the preceding wheat crop, and within the WSSF rotation, the second sorghum crop yielded 37% less than the preceding sorghum crop.

The water productivity of WSSF was greater than all other rotations, and was found to produce the greatest yield when a wheat equivalent yield was applied in order to compare it to WWSF and WW rotations.

We determined that the four-​year rotations in this study were not more productive compared to the three-​year rotations.

Publication: Schlegel, A.J., Y. Assefa, L.A. Haag, C.R. Thompson, J.D. Holman, and L.R. Stone. (2017). Yield and soil water in three dryland wheat and grain sorghum rotations. Agron. J. 109:227-238.

Go to article