One of the most significant agronomic challenges related to perennial grains is that grain yields decline stand age. For Kernza®, yields tend to drop dramatically after the second production year. Our research is focused on 1) determining why yields decline with stand age and 2) how we can prevent yield declines with stand age.
One thought is that yields decline with stand age because stands become more dense through time, which increases competition for soil resources. The plants could be responding to this increased belowground competition by investing more resources in roots at the expense of grain. We’re measuring Kernza® roots of plants varying in stand density using belowground root imaging technology (mini-rhizotrons).
If grain yield declines are associated with increasing plant density, one thought is to reduce plant density by inter-row cultivation. We are using a multivator to cultivate between rows of Kernza® to see if we can prevent yield declines with stand age. Click here to see a video of the mulivator in action.