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When Roger Zylstra and his son Wesley started experimenting with cover crops on their central Iowa farm in 2014, they weren’t exactly sure what to expect. They had a goal to improve stewardship of their land and resources but, at the time, didn’t really know where that would take them. Their experiment – cereal rye before soybeans – seemed to be yielding benefits, but they wanted more hard data. So, in 2015, Roger enrolled in an SHP cover crop trial to better understand the impact of this management practice on their farming operation.

Roger and Wesley’s experience with SHP is detailed in a new business case, sharing where they started and what they have learned after conducting their trial for five years. Below are some of the Zylstras’ key learnings. Dig into the full business case to find out more.

Build soil health in a way that works for your farm

In addition to growing corn and soybeans, they also raise hogs on the Zylstra farm. The incorporation of livestock makes manure an important source of nutrients for their cash crops, and it was something Roger and Wesley considered when choosing to implement cover crops.

“We’re working to continue to be competitive with our yields, while striving to improve the health of our soil,” Roger said. “Because we have swine and fall-apply the manure, we think cover crops really help sequester the nitrogen to the soil.”

They chose cereal rye as their cover crop species specifically because of its ability to withstand disturbance caused by injecting manure, recognizing that it bounces back quickly with minimal impact to the stand. Cereal rye also overwinters well, which provides ground coverage and nutrient uptake throughout the fall and spring.

It is okay to make changes over time

Roger knows how easy it can be to want to make all the changes at once, but his experience with SHP taught him that it can be valuable to make incremental shifts – evaluating your results and then adapting accordingly.

Here are just a few of the things that have changed in the Zylstras’ approach since 2015:

  • Eliminated use of fall anhydrous and incorporated spring pre-plant and sidedress applications
  • Adjusted cover crop seeding rates
  • Experimented with different methods of cover crop seeding (switching to drilling for a few years before returning to spreading/incorporation with vertical tillage)
  • Moved to 100% liquid application of fertilizer
  • Experimented with planting green

Each of these adjustments from year-to-year allowed them to dial in their system in a way that best met their unique needs around labor, time, and equipment resources. You can read more about the specific reasons for these changes in their business case.

Small changes add up to real benefits

By staying committed to building soil health, making incremental changes, and experimenting with different approaches, the Zylstras have seen real benefits to their farming operation. Some of the biggest takeaways include: 

  • Improved nutrient use efficiency – By changing the sources and timing of nitrogen application, they see greater utilization by the crop and reduced leaching of nutrients into the waterways. According to Roger, “We use about the same amount of nitrogen per acre as we did many years ago, but our average [corn] yields have grown from 140-170 bu/acre to 170-200 bu/acre.
  • Increased microbial activity – Results from soil health testing on their SHP field shows that respiration (an indicator of microbial activity) has increased significantly on the cover cropped portion of the field, aiding in an improved rate of residue turnover on those acres.
  • Improved soil structure – The Zylstras credit improvements in soil structure with reducing soil surface compaction during the wet years of 2018 and 2019. In comparison to nearby farms (who faced standing water and ruts in the field), Roger and Wesley experienced fewer equipment tracks and less ponding. At times, it has also allowed them to get into the field a day or two earlier during planting and harvest. 

Digging In

When it comes to building soil health, no two farms are exactly the same. However, there are things we can learn from each other as we experiment, adapt, and experience success. Farmers who leverage manure as a primary source of nutrients can see from the Zylstras’ SHP program one way to implement cover crops and things to take into consideration when getting started. And, no matter what your system looks like, Roger’s advice to take it day-by-day and season-by-season – adjusting your practices over time to find the approach that works best for you and your farm – is something we can all learn from.