Breeding crops for crop rotation will increase yield and reduce fertilizer costs

Experts note that each plant leaves behind certain changes in the soil: reserves of nutrients and water, structure condition, and microbial community. The benefits of crop rotation have been known for centuries, yet breeders have long ignored the genetic mechanisms of this phenomenon. The Queensland Alliance for Agriculture and Food Innovation team considers crop rotation as a genetic challenge rather than just an element of farm management.

During an experiment at a research station in southern Queensland, scientists grew over 300 genetically distinct species of mung bean, after which they planted the exact same wheat cultivar in all plots. The results showed a significant difference: some mung bean samples increased the yield of the following wheat by 45%, while others reduced it by half. Professor Lee Hickey reported that the researchers managed to identify specific regions of the mung bean genome affecting the productivity of the subsequent crop. At the same time, it turned out that some genetic factors work against each other: genes ensuring high yield for the current plant may leave fewer soil resources for the next one.

Modeling of co-selection for the yield of the mung bean and the subsequent wheat demonstrated an increase in performance for both crops. This indicates the possibility of increasing the overall productivity of agricultural systems while reducing fertilizer application rates. The effect has been recognized as real and heritable, but further work by the scientific community will be required to understand the biological mechanisms. According to Dr. Millicent Smith, although the experiment was conducted with mung beans and wheat, this approach is also applicable to other crop pairs, including canola with wheat and chickpeas with barley.