We investigated the long-term impact of three tillage intensities (conventional, reduced and no-till) on dryland grain sorghum and winter wheat yield, available soil water, and water productivity. The study was conducted at Kansas State University Southwest Research-Extension Center. A wheat-grain sorghum-fallow rotation was managed with no-till, conventional, and reduced tillage from 1991 to 2015.
We found on average a 120% yield advantage of no-till grain sorghum over conventional tillage, and a 55% yield advantage of reduced-till grain sorghum over conventional tillage. No-till winter wheat had a yield advantage of 31% over conventional tillage, and reduced till winter wheat had a yield advantage of 12% over conventional tillage. Furthermore conventional tillage rotations had less available soil water at planting compared to no-till and reduced tillage. For years 2001-2015, the reduced tillage treatment was a combination of conventional till wheat in rotation with no-till grain sorghum.
This system produced grain sorghum yields 45% less than the continuous no-till system. To obtain maximum benefit from no-till for grain sorghum, it must be done continuously and not in rotation with tillage.
Publication: Schlegel, A.J., Y. Assefa, L.A. Haag, C.R. Thompson, and L.R. Stone. (2018). Long-term tillage on yield and water use of grain sorghum and winter wheat. Agron. J.