Ohio State Completes Five-Year Study of Soil Balancing

[WOOSTER, OH] --The Ohio State University is concluding a five-year project examining the beliefs, practices, and effects of soil balancing. Soil balancing involves the use of high calcium amendments to manipulate the ratio of calcium, magnesium, and potassium in the soil. For decades, proponents have claimed that the right balance of these cation nutrients will improve field conditions and yields, but none of these effects have been replicated by modern university research.

Using a survey of certified organic corn growers in Ohio, Michigan, Indiana, and Pennsylvania, the Ohio State study found widespread use of soil balancing among organic farmers in the region. Despite the lack of scientific support, more than half of the surveyed growers used soil balancing. The survey, conducted in 2018, had a 57% response rate with a margin of error of +/- 2%.

Through interviews, surveys, and literature reviews, the team gained a better understanding of why and how soil balancing is used by farmers and how it had been studied by researchers. The group found that while most researchers and university educators viewed soil balancing as an ineffective fertilization program; farmers and consultants who use soil balancing view it as a holistic method for improving soil health.

With input from a farmer advisory committee, the team designed their own field experiments, addressing several of the identified gaps in understanding between researchers and farmers. Experiments were conducted on organic farms over multiple growing seasons and measured numerous possible effects. The field trials found some evidence that changes in Ca:Mg ratios were associated with changes in soil structure and weed populations. However, the team was unable to document consistent effects on these characteristics, or on soil biology, crop quality, or yield. Based on the overall project findings, the Ohio State team recommends further investigation of how soil balancing’s effectiveness is impacted by specific site conditions such as cation exchange capacity (CEC), clay content, or management practices.

Most of the crop consultants interviewed for the study indicated soil balancing is most effective on clay soils with CEC greater than 10 meq/100g. Farmers using soil balancing on low CEC soils are cautioned to watch for potassium and magnesium deficiencies, which were documented on low CEC sites in this study.

The 2018 survey of organic corn growers also gathered information on management practices and economics. The survey found most (75%) of the organic corn in this area is grown on livestock or dairy farms and 60% of the corn is used on-farm for feed. Additional survey topics included the use of soil amendments, tillage practices, and crop rotations. Economic analysis found that organic corn growers had widely varying yields, incomes, expenses, and net returns. but nearly all farms reported positive returns to labor and management from their organic corn enterprise. On average, soil balancers had higher yields but also spent more on inputs. Therefore, net returns were similar.

This study was funded by a USDA-NIFA OREI grant.

Additional details on the organic corn growers survey are available at go.osu.edu/orgcorn.

Read more about soil balancing at go.osu.edu/sb