Soil DNA tests provide early warnings

EL PASO, Ill. — Yield-limiting problems in fields are typically found and addressed during the growing season or discovered at harvest when it’s too late.

A soil DNA testing program uses genome sequencing to find problems well ahead of planting so farmers can take disease, pest and fertility management plans early on.

Pattern Ag’s soil meta-genomics tool identifies compounds produced by microbes in the soils and provides long-term predictions about crop risks in row crops.

Chad Kalaher, Beck’s Hybrids field agronomist, said the seed company has been working with Pattern Ag since 2019 at Practical Farm Research sites.

“When we talk about yield-limiting factors in-season it’s really after that seed was planted. We have many diagnostic tools to identify yield-limiting factors once the seed is planted. Using the soil DNA test by Pattern Ag you can identify what your pressure is in the field before planting,” said Kalaher at Beck’s Central Illinois Field Show.

Sampling

Under standard sampling protocol, a field is divided into 10-acre grids and 12 samples are pulled from each grid and combined into a single composite sample for the lab.

“Pattern Ag has a gene mapping library that can identify the pressure of the pathogens or pests based on the genes in the soil. For example, a rootworm egg in the soil is not what they’re looking for from the soil sample. They’re looking for the genes that egg is producing in the soil and they identify the pressure off of that,” Kalaher said.

“Instead of wondering what happened at harvest time, we can manage it on the front end before the seeds are planted.”

—  Chad Kalaher, field agronomist, Beck’s Hybrids

Beck’s began utilizing Pattern Ag in 2019 in fields where the seed company has been conducting long-term tillage and rotation studies.

“Pattern Ag found high levels of soybean cyst nematode, high levels of sudden death syndrome in our long-term trials depending on the rotation and depending upon tillage,” Kalaher noted.

“We felt it was a valuable tool. So, in 2020 I was to be one of two agronomists across the company to be able to take this out in the field over about 1,000 acres. We did that with many operations. It was expanded to 2,000 acres last fall.”

Risk Levels

As an example of the service, Kalaher highlighted the findings of a 55-acre field sampled after the corn harvest.

The sampling found moderate risks for rootworm, soybean cyst nematode, anthracnose, soybean brown stem rot and fusarium, and high risk for SDS, soybean stem canker, white mold and pythium. It also indicated the portions of the field where the risks exist.

“This is from a corn stalk field in the fall of 2021. Let’s assume it was rotated and planted into soybeans in 2022, we wouldn’t be concerned about every one of those pests and diseases found in the soil. We wouldn’t be concerned about rootworms if we were planting soybeans, but we would be concerned about soybean cyst nematode, sudden death syndrome, and some of the other diseases,” Kalaher said.

“This would help me make some decisions about the management of these soybeans. I would know that white mold, soybean stem canker, pythium, sudden death syndrome, needed to be managed in that soybean crop. This could identify a lot of the pathogens that could potentially be yield-limiting.”

Using the information for that 55-acre field, management techniques to consider would include variety selection based on susceptibility to certain diseases, seed treatments and in-furrow fungicide application.

Mapping

“If we see variable pressure from diseases and insects and we have the ability to variable rate apply, for example, a fungicide, with a planter pass we can save money on parts of the field by only applying where it’s needed. That could be done with fertilizer, as well,” Kalaher said of the mapping capabilities.

“These are identified all based on genes that are in the soil. It’s basically gene mapping for pathogens. I think the biggest advantage of Pattern Ag’s gene mapping and profiling is the pathogen screen.

“This tool is to be more of prescriptive analytics, diagnosing or managing the problem before it happens in the field. Instead of wondering what happened at harvest time, we can manage it on the front end before the seeds are planted.”