Intercropping and Relay Cropping

The idea of intercropping - or growing two crops at once, has theoretical appeal of creating synergies for pest and disease management, fertility, and overall productivity. But is this really possible in practice? In today’s episode we talk to three applied researchers about what the data shows when it comes to intercropping and relay cropping. We will explore a few different intercropping and relay cropping combinations, the benefits and tradeoffs, and what to consider before trying any of these systems. This audio was taken from the DIRT Workshop this past fall.

Today you’ll hear from:

• Dr. Mike Ostlie a research agronomist at the NDSU Carrington Research and Extension Center.
  
• Dr. Marisol Berti a professor in the plant sciences at NDSU
  
• Dr. Russ Gesch a research plant physiologist with USDA ARS in Morris, MN
  

“When we have more than one crop growing in the field, I think the first thing you have to realize is you're not looking to maximize the yield of either of what you're growing. You're looking for more total yield.” - Dr. Mike Ostlie

It’s important to keep this in mind because producers will likely see some decrease in yield in both crops as opposed to planting them as a single crop. Overall you should appreciate an increase in the efficiency per acre by achieving an overall production increase between the two crops. Dr. Ostlie does suggest identifying a “dominant crop” in order to best target your management practices and meet your individual needs and goals.

Dr. Berti introduces us to the concept of relay cropping. While intercropping involves planting and growing two crops concurrently with the same expected harvest timing, relay cropping involves overlapping life stages of two crops with separate harvests. Dr. Berti sees a lot of benefit in a corn/alfalfa system she is researching. Alfalfa is not profitable during its seeding year but will be the following year so overlapping with another crop allows for ongoing production while waiting for the alfalfa to mature. The biodiversity, nitrogen fixation and improved water infiltration of including the alfalfa will also benefit the overall soil health while producing a concurrent cash crop.

“I don't think farmers should be afraid to try (camelina) out and use it as a cover crop even if they're not going to grow it out to maturity and harvest it because it does have some good cover crop benefits and ecosystem services that it provides.” - Dr. Russ Gesch

Dr. Gesch shares that markets are emerging making the use of intercropping prospects like camelina more profitable for producers. In the meantime benefits such as biodiversity, supporting the insect ecosystem and suppressing weed growth can be of great benefit for producers. All of our experts advise producers to trial these methods on their operations in small amounts at first to limit potential risk while evaluating and adjusting for the most benefit.

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Soil Sense Podcast is hosted by Tim Hammerich of the Future of Agriculture Podcast.