Soil subtleties

Kyle Brase uses a wide array of high-tech tools to measure and manage soil nutrients on his southwest Illinois family farm, but he says one of his most valuable assets is the service he gets from CHS Shipman Agronomist Joe Huebener.

“We’ve collected field data for many years, and Joe has helped us turn a cumbersome analysis process into a positive experience,” says Brase. “He’s helped us use yield data to focus inputs on the highest-yielding parts of our fields. We’ve increased yields, sometimes even while lowering crop nutrient rates.”

Maximizing nutrient efficiency not only helps boost yields and profit but also reduces chances that excess nutrients will end up in local waterways. Living and farming near Hamel, Ill., east of St. Louis and just 10 miles from the Mississippi River, the Brase family has always been concerned about potential runoff. That’s why Kyle, who farms with his uncle Bill Brase, brother Mark Brase and cousin Eric Brase, was quick to embrace the 4Rs nutrient management concept years ago. “It makes sense for both financial and environmental reasons and seems like something every farmer should be guided by,” he says.

The commitment of Brase and Huebener to using the 4Rs — choosing the right nutrient source to apply at the right rate, in the right place, at the right time — earned them The Fertilizer Institute’s 4R Advocate award for 2017. In its sixth year, the national program annually recognizes five producer-retailer teams who implement 4R strategies to increase yields, improve soils and decrease their fertilizer footprint on the environment.

Loving Data Layers

At Brase Farms, they’ve been grid soil-sampling since long before it was an automated process. “My uncle started doing things by hand in the ’80s,” says Brase. The information gathered may not have been as accurate then as it is now, he admits, but they have decades of soil data on some fields.

They’ve also gathered yield data for years, but Brase says they started making the best use of it when he began working with Huebener and the CHS YieldPoint® precision ag program three years ago, layering data to create high-, medium- and low-management field zones.
 
“We’re now able to fertilize each part of the field based on what the previous crop has removed from the soil. Some of the most fertile zones have produced corn yields of 320 bushels per acre, while our overall average is around 200 bushels. The following year, we’ll fertilize each management zone within a field, based on its production potential, focusing production potential, focusing on the most productive areas.”

The CHS YieldPoint system enables smarter soil sampling, says CHS Shipman Agronomy Manager Regan Wear. “By sampling more intensely in areas of the field that fall outside average results, you can often get a clearer picture of what’s different in those soils and why.”

In-season plant tissue testing confirms growing crops have necessary nutrients, says Brase. “We rarely need to make an in-season rescue treatment, but use the results to identify occasional nutrient deficiencies.”

Customizing Soil Solutions

In the southwestern Illinois trade territory of CHS Shipman, there’s considerable soil type variability, even within the same field, says Huebener. “Kyle’s willingness to regularly run strip trials on his farm — varying not just fertilizer rates but hybrids and seeding rates — has helped us to see how we can better customize inputs within a field to get the best yields and biggest returns.”

For many growers, focusing on nitrogen efficiency is a good place to start, says Huebener. “Running field tests in corn where we double the nitrogen rate in one strip and use a half rate in another strip is a good way to see how much the crop is actually using,” he says. “It’s another source of information we can use to fine-tune application rates. The nitrogen-to-corn ratio [pounds of nitrogen required to produce one bushel of corn] in Kyle’s field is about 0.9, which is good, but we hope to whittle that down another tenth or two in the coming seasons.”

With today’s tight crop margins, too many growers are focused on reducing input costs when they should be making sure they’re getting the best return from their inputs, says Huebener. “Sometimes that means cutting nitrogen rates for some parts of the field and nudging them higher in other areas. Variable-rate application is the best way to achieve that by applying the right amount in the right place.

“We also regularly use the Maximum Return to N calculator to determine the most efficient nitrogen rates for corn,” he adds.

When it comes to choosing the right time to apply, he says many growers, including Brase, are waiting until spring to apply nitrogen, especially on highly erodible areas. “Those who make fall applications are being careful to do it when soil temperatures are right,” says Huebener.

Shifting Cultural Practices

Technology has been the major driver of improved nutrient management, but shifting cultural practices plays an important role  as well, says Mary VanderBeek, CHS Country Operations sales development manager.
 
“We talk a lot about helping growers become more efficient producers from a financial standpoint, but improved efficiency should also mean they’re being better stewards of their land and improving soil for the long term,” she says. “That’s why CHS supports The Fertilizer Institute and the 4R Nutrient Stewardship program.”

The trends toward reduced tillage and increased use of cover crops are important options that more growers should consider as they take a more holistic approach to farming, she says. “There’s still a lot being learned about how to manage cover crops in corn, for instance, but it’s another management tool for improving soil health and water-holding capacity over time.”

Results from an eight-year study coordinated by Iowa Learning Farms with the help of a dozen farmer-cooperators show cover crops hold promise for both corn and soybeans. The farmers reported that, in 55 of 59 sites, properly managed cover crops had little to no negative effect on corn and soybean yields and actually increased soybean yield in seven site-years and corn yield in two.

Using cover crops to scavenge unused nitrogen and phosphorus makes them a valuable tool for minimizing nutrient loss, says Wear. “In our area, the two most common reasons growers use cover crops are to help clean up nitrogen remaining after a corn crop, which reduces nitrate runoff, especially in tiled fields, and to minimize soil erosion, which is one of the biggest sources of phosphorus loss into waterways.”

For that reason, growing winter wheat after corn on about 10 percent of total acres has become part of the Brase Farms rotation.

“Oats has also become a common cover crop to seed with sugar beets,” says VanderBeek. “Oats grow quickly and provide some protection against strong winds that can twist off the tops of newly emerging beet seedlings.”

Shifts in tillage practices continue to take place. According to the most recent Census of Agriculture in 2012, about 32 percent of U.S. cropland acres were no-tilled, 22 percent received conservation or minimum tillage and 46 percent were conventionally tilled. In the CHS Shipman area, Wear estimates about 20 percent of acres are no-till, 50 percent are minimum-till and 30 percent have conventional tillage.

“Our growers are definitely trying to reduce the number of tillage trips they make, and minimum- or no-till works fairly well here ahead of soybeans,” he says. “I expect the number of conventional-tilled acres could drop more in the coming years, with more moving to minimum-tillage systems. From a nutrient management standpoint, strip-tillage might be the best option for our part of the country, since some phosphorus incorporation helps reduce runoff and that’s a concern here.”