Cole Mertens runs a farming and stocker cattle operation with his family in northeastern Colorado. As far as anyone can tell, the tradition of farming has been in his family for seven generations. As a dryland farmer, Cole grows crops like wheat, corn, and millet without any irrigation in a region that only averages 15 inches of annual rainfall.
The following interview has been edited for clarity and length.
Steve Rosenzweig: If you weren’t a dryland farmer, what would you be doing?
Cole Mertens: Probably something where there's less stress about rainfall.
SR: How do you deal with the stress of not being able to count on rain?
CM: I guess it's something that I've grown up with my entire life - it's something that we're really used to. It's that uncertainty that's pushed our farming systems to be able to store water. We use systems like no-till that enable us to plant crops like corn, so we can store the water through the wintertime and use it in the summertime. Honestly, the early years of my farming career were a lot drier than what we've been experiencing lately so I think I got broke in pretty good from the beginning. We just didn't have rain for about 5 years in the early 2000's and 2002 we never harvested any fall crops whatsoever. That really opened my eyes of what this country can be, and then when you do get years where you get good moisture, you're that much more appreciative of it.
SR: You mentioned no-till is an important tool for you as a dryland farmer. When did you make the switch to no-till?
CM: Honestly, I wasn't motivated to switch to no-till. My uncles and father switched long before I was involved in this farming operation, but I could see the benefits as a young kid. I've just always been on board and this is the system that we're going to have on our farm as long as we can make it work. We would have some land that has been in no-till production for close to 30 years.
SR: What changes in the soil have you noticed over that time?
CM: The organic matter in the soil is going up. You can see when you pull this up it’s just really dark black, wet, cool. That organic matter is like a sponge to hold water in the soil for later crops. The other thing that we're seeing is that we saw benefits at 5 years and 10 years, but some of our land hasn't been worked for 20+ years and now we're really starting to see yield gains on those fields that have been no-tilled the longest. It's a long healing process. All that tillage through all the years definitely broke down, did away with any earthworms or anything that was living in the soil. But it's like it's almost like a fine wine, it gets better and better and better as time goes on, so we don't really know if 50 years what this soil might be capable of.
SR: You’re part of the younger generation of farmers. What are the biggest challenges your generation of farmers will face?
CM: I think the big thing for my generation is to climate-proof ourselves I guess against the hot, dry years that we know are coming back as they always do. We have to build on the no-till legacy, and figure out more crops to introduce to the system and how they work.
SR: Tell me about your crop rotation.
CM: Our crop rotation mostly involves wheat, corn, fallow, and millet. We're either growing 3 crops in 4 years or 2 crops in 3 years.
SR: Tell me about the fallow period.
CM: This field behind me is what we call summer fallow. It's where we just leave a field lay with no crops for an entire summer, and then plant it to winter wheat that fall. Part of the reason we do that is to store moisture, and part of it is we just see more productive capacity out of fields that have been summer fallowed. We always have seen a yield drag when we continuous crop our winter wheat. Fallow kind of evens out the highs and low in terms of the uncertainty of rain. And the other thing that we're accomplishing with the summer fallow is we're growing a really thick heavy winter wheat crop that produces good residue to start off our rotation when we go into corn and millet.
SR: What benefits do you get from having multiple crops in rotation?
CM: What we gain mostly from having diversity in our crop rotation is that you never know what the weather's going to do or when it's going to do it. Sometimes our rain might come in one 4"rain one afternoon and we won't get any for a couple more months. We need to be able to put that rain in the soil where we can use it for later and not watch it run off, and that's one of the huge benefits of rotation. We benefit from diversity in our crop rotation, even though it's maybe not as diverse as what it should be. But we're always looking for new things to add to the system. Corn is a completely different type of plant than say a wheat, for instance with the roots that it puts in the ground and the channels that it creates. It helps increase the water holding capacity by infiltrating and opening up pore space in the soil so the water can get in when we do get our rainfall events. The field that we're in this corns planted into last year's wheat residue and that wheat residue will break down as the corn's growing and this residue acts as mulch just as in your garden or anything else. It protects that soil. We just dug this up. This soil is completely wet and cool and we haven't had measurable rain here in almost three weeks and we've had a lot of near 100-degree temperatures in the last three weeks.
Steve Rosenzweig is a PhD Candidate at Colorado State University. This interview was conducted as part of a film project to document emerging innovations in dryland agriculture, which can be viewed here.