Narrow Rows Key to Increasing Yield

Of all the inputs you can use, nothing boosts yield as effectively as narrow rows

Three years, six states, and everything but the kitchen sink went into one soy checkoff-funded study to find the best way to maximize U.S. soybean yields.

The Maximum Yield through Inputs study, nicknamed the Kitchen Sink study sought to identify the optimum combination of inputs for maximizing soybean yield. To do this, researchers compared the yields from test plots where various combinations of inputs and other crop-management variables were used with crops grown without any additional inputs, which included seed inoculants, treatments and foliar fungicide.

Seth Naeve, lead investigator and University of Minnesota associate professor of agronomy and plant genetics, recently talked about what the results of the study mean for U.S. soybean farmers.

Q: How is this study unique?

A: It was one of the first applied soybean production research projects carried out across a large number of states. The study covered a large range of environmental factors, allowing us to generate a tremendous amount of data.

Q: What can farmers learn from the study?

A: Because of high soybean prices, farmers are searching diligently for ways to increase soybean yields. The study suggested that narrow row spacing, which is an older strategy compared to the inputs, is the single most important factor in increasing yield. This point is so important now because it contradicts what a lot of farmers are doing, moving towards wider rows to accommodate larger planters and trying to buy higher yields with more products.

Q: What were some of the challenges of organizing a study of this size?

A: We had a lot of little challenges. We wanted everything to be as unified as possible across the states involved in the study, yet we had to replicate local conditions and farming practices in each area. For example, due to the scale of the project we could not use the exact same equipment, like planters, at all of the locations. Seed and varieties also had to change because of the range of environments and maturity groups we faced between the Gulf of Mexico to the Canadian border.

Q: Did the study’s results surprise you?

A: It didn’t necessarily surprise us. Our research has shown us that narrower rows increase yields, but we didn’t think it would show up as prominently as it did. Farmers have a hard time believing narrow rows have such an effect on yield because they don’t have a way of testing it on their farm. We were certainly surprised that we didn’t see more yield increases from some of the inputs.