The lure and reality of conservation tillage

This past week I had the opportunity to get out in some farm fields with our recently hired agronomist, Jennifer Hahn. Jennifer is a University of Minnesota Extension Educator, but she is 100% dedicated to working with farmers in the Lower St. Croix watershed and is based out of the Washington Conservation District office in Oakdale, Minnesota. Her job entails providing technical expertise, conservation planning, and educational opportunities for agricultural landowners.

It’s been a really stressful spring for our farmers – the cold of April and torrential rains of May have delayed planting by weeks. While we initially hoped to have the farmers chat about their operations themselves, their priority was obviously getting seeds in the ground! What we were able to observe in the field, however, was how different conservation tillage practices have helped enable these farmers to get their planting done when other farmers around the basin are dealing with muddy fields and equipment getting stuck.

Tillage refers to turning or mixing of the soil. In the last several decades, the majority of farmers have practiced conventional tillage, which requires using a plow and additional tillage equipment to completely overturn the soil, creating a nice, fluffy soil bed that warms quickly and is easy to plant into. Conventional tillage is what you generally see when you look at glossy agricultural marketing materials, with the field plowed in neat rows of dark soil.

Left: Conventionally tilled field. Right: No-till field with residue from the last corn crop. Which field appeals more to you?

However, such tillage practices have distinct disadvantages. Bare soil is more prone to erosion by wind, rain, and runoff. I can guarantee no farmer likes to see his/her soil washing off his field, especially when the fertilizer applied to the soil runs off with it. Furthermore, while soil and fertilizer are valuable on the field, they become pollutants to receiving streams, rivers, and lakes, degrading water quality.

The HORRORS: Bare fields mean soil is more vulnerable to erosion.

Tillage also destroys soil structure and reduces soil health, leading to a reduced capacity for the soil to retain nutrients and infiltrate/store water. Finally, tillage requires that farmers make more passes on their fields – once in the fall (generally), once in the spring, and once to plant – that’s more time on the field, more fuel costs, and more equipment wear and tear.

Conservation tillage practices, which include reducing the amount of tillage or not tilling at all, are at the opposite end of the spectrum. Reduced tillage and no-till includes leaving crop residue on the field after harvest and prioritizes leaving the soil undisturbed as much as possible. These fields look different – you might call them ‘messy.’ I’ve found farmers in many cases think about no-till fields the same way many lawn-dedicated folks think about ‘weedy’ native plant gardens. They just don’t fit with the narrative of what a ‘proper’ field or yard should look like.

Close up of a ‘messy’ vertically-tilled field. Vertical till, a type of reduced tillage, only lightly tills the upper few inches of soil and helps cut up residue.

Aside from how it looks, though, conservation tillage offers some pretty compelling benefits. First and foremost, conservation tillage means less soil erosion and water runoff. Residue roots hold the soil in place and create channels that can more easily infiltrate water. The plant remains slowly decompose and contribute organic matter to the soil, increasing its ability to retain and store nutrients and water year after year. While the residue can prevent soil temperatures from warming as quickly in the spring, the residue also provides a solid base for farm equipment traffic, leading to less compaction and equipment sinking into wet fields. Plus, reduced tillage/no-till means less passes over a field (only once, maybe twice in the year), translating to less time the farmer has to be working in the field, less money that needs to be spent on fuel, and less wear and tear on equipment.

And finally, the data continues to add up that farmers who practice reduced tillage and no-till year after year generally have less need for fertilizers, increased yields, and higher profits.

Given all this, many would wonder why so many farmers still practice conventional tillage when there are so many benefits to reduced tillage and no-till practices.

The answer, of course, is that it’s complicated. No-till does require some specialized equipment that a farmer may not have access to or can afford. To help improve access, many soil and water conservation districts (including the majority of those in the Lower St. Croix watershed) offer no-till drill rentals for local farmers. A recent survey distributed by the Pine SWCD found that many farmers who rented their drill were quite pleased with the results, with a few even deciding to purchase their own no-till drill to continue their practice.

An example of a no-till planter. The farmer has both spiky and smooth closing wheels installed on the back to help bury the seeds given variable soil conditions across the field.

While many farmers practice no-till in the fall, many still turn to conventional tillage in the spring due to the challenges of planting in residue. Residue can be hard on equipment and when first adopting no-till or reduced tillage, unexpected planting challenges can waste time and money that farmers can’t afford to lose.

Perception and tradition are still definitely barriers to more adoption of conservation tillage, where farmers are content to continue “how it’s always been done” because “it was good enough for those before me.”

But perhaps the biggest barrier, which touches on all of the issues mentioned above, is that making any changes to one’s farming operation changes the risk threshold for that farmer. Learning a new technique, making sure you have the equipment you need, troubleshooting, and then making adjustments to the rest of your practice (nutrient or pest management approaches, for example) introduces more uncertainty and risk (as well as time and cost). Many farmers already work with pretty slim profit margins, so taking the leap to change tillage practices is no decision to make on a whim. Honestly, it’s a risk many farmers just don’t want to take on, especially because these practices usually need repeated years of implementation before you really see the benefit of improved soil health and increased yields.

Still, the story we saw out in the fields was compelling. We saw loads of corn and soybean residue, with little evidence of soil erosion or channelized runoff. While the farmers had hoped to plant earlier this spring, they were having little issue moving their equipment around the fields. It was the first pass several of the farmers had made this season.

We didn’t observe any evidence of soil erosion in these no-till fields, even though our area has been pounded regularly with intense severe rains over the past month.

Changing tillage practices is no small decision, but there are a growing number of resources that are meant to help encourage farmers to take a second look at conservation tillage. The Lower St. Croix Watershed Partnership is launching a cost-share program this summer with financial incentives for adopting reduced and no-till practices. Contact your local SWCDs in Chisago, Pine, Anoka, Isanti, and Washington Counties to learn more!

In the meantime, enjoy our new YouTube series, Out Again with Jenn, which gives you a closer look at some of the fields and planting techniques we were seeing out in the field.

Extension educator and Lower St. Croix watershed agronomist Jennifer Hahn talks about a Washington County farmer planting soybeans in a corn residue no-till field.
Extension educator and Lower St. Croix watershed agronomist Jennifer Hahn talks about a Chisago county farmer planting corn in a no-till soybean residue field.
Extension educator and Lower St. Croix watershed agronomist Jennifer Hahn talks about a Chisago county farmer planting soybeans in a vertically-tilled field.