Producers are continuously fine-tuning their production practices, seeking ways to use labor and capital more efficiently and increase profits while protecting the environment. This includes making better and more efficient purchasing decisions and developing improved marketing strategies to create more profit from their farming operation.
Relay cropping is essentially a special version of double cropping, where the second crop is planted into the first crop before harvest, rather than waiting until after harvest as in true double-cropping. In this way, both crops share a portion of the growing season, increasing solar radiation and heat available to each.
The rotation of corn grown for seed and soybean seems to be well suited to relay cropping because seed corn is harvested in mid-September (earlier than full-season field corn) and the remaining residue is not excessive. A winter annual crop, such as winter wheat, could be inserted into the seed corn-soybean rotation to use the solar energy and heat units available between corn harvest in September and soybean planting in May. However, winter wheat is not harvested until mid-July — far after the optimum time to plant soybean.
Hence the need to relay crop the winter wheat and soybean in this seed corn-winter wheat-soybean crop sequence. For successful relay cropping, several things would usually be necessary in Nebraska: center-pivot irrigation, glyphosate-tolerant soybeans, and a means of seeding soybeans into wheat at heading (about 30 days before wheat harvest).
System pros and cons
Relay cropping has advantages and disadvantages compared to standard cropping practices. Advantages include are:
- the potential to reduce nitrate leaching (wheat acts as a scavenger crop),
- increase carbon sequestration,
- and increase income for producers.
Unfortunately, a relay cropping system is not without risk. Disadvantages:
- The soybean planting process will likely stress the wheat crop and reduce yield from what would be expected of a non-disturbed crop.
- Likewise, wheat harvest may stress the soybean crop.
The hope is that the two crops will result in greater income (and profit) than either single crop grown without disturbance.
- Relay cropping requires a greater level of management. Wheat must be planted during the soybean and corn harvest season and planting soybean into a standing crop is a new process to most farmers.
- Also, pest management and control practices must account for more crops being grown in close sequence. The system may not allow time for herbicide carry-over levels to decline and may increase the potential for insect and disease infestations if these pests have more than one host in the crop sequence.