Intercropping is a crop management practice that includes sowing seeds into a standing crop. Benefits of intercropping are diverse, but typically include the highest benefit related to weed control, soil health, and erosion control, as the cover crop has time to establish before the standing crop is harvested and removed from the field – thereby avoiding a period of time without canopy or living roots (Peterson et al., 2019). Relay intercropping is a specialized approach to intercropping, as multiple crops (usually a cool season species and a warm season species) are sown with the intent to harvest both of them. This system produces two crops in semi-sequential fashion, establishing a second crop in interrow spaces before the first crop is harvested. Rationale for this practice is focused on facilitating multiple crops in the same season for areas with shorter seasons, but also incorporating some benefits of intercropping as a component of regenerative agriculture practices in a more logistically feasible fashion (Gesch et al., 2023; Moore et al., 2019).

 

While these relay-style systems are relatively established in public knowledge, sparse data is available on best financial/agronomic management practices, including the relative benefit to established cropping systems in the Central Plains. The need is not to reinvent intercropping, but to dial in on what is preventing adoption, refine the system, educate agronomists and farmers about monoculture alternatives, and translate field research into tangible resources for farmers to implement on their own farms (Lamichhane et al., 2023).

 

Winter wheat, which requires a vernalization period, is planted in the fall and harvested in early summer of the following calendar year. The logistics of the wheat cycle complicate crop rotation and unfortunately lead to a barren period after harvest in June, providing opportunities for weed encroachment and soil erosion for the remainder of the summer. A common, intensified alternative to this fallow period is multiple (double) cropping. Double cropping is a sequential monoculture system (producing two crops) commonly adopted in areas with sufficient soil moisture following wheat harvest. Soybeans (or grain sorghum) are planted immediately after the wheat is harvested, which allows for the production of short-season soybeans/sorghum. These double-crops do not have the yield potential of single-crops planted earlier in the season, as is the typical practice. Later planting dates of double-crops has been demonstrated as a yield-limiting factor in Kansas, especially for soybeans (Santos Hansel et al., 2019). This yield gap could potentially be alleviated by planting the second crop earlier, before wheat is harvested. Although relay intercropping is more commonly implemented in upper Midwestern regions with shorter growing seasons and more reliable precipitation, such practices showed promise in Kansas several years ago (Duncan et al., 1990; Duncan & Schapaugh, 1997). Regardless of this fact, these regeneratively-focused practices have not been implemented or refined, even 35 years later. Translational research is desperately needed in the intercropping space, specifically with relay intercropping, as a logistically feasible option for Kansas farmers.