Though planting crops more densely can be an effective approach for suppressing weeds in problem areas, many growers fail to adopt this approach because of the high cost of seed. New research featured in the journal Weed Science, though, describes a bioeconomic model growers can use to overcome that cost barrier.

A study conducted in maize, cotton and soybean crops suggests it is possible to affordably balance higher-density plantings in areas with weed escapes against lower-density plantings elsewhere in the field – without sacrificing yields and profits.

The authors don’t recommend a “one-size fits all” approach, though. Instead, their study demonstrates that distinct physiological differences among crops influence the balance needed to achieve a cost-neutral result.

For example, maize grown at a 75% planting density produced a 229% increase in yield, a 43% increase in return and a 79% increase in profit as compared to areas planted at a 2X density. Cotton planted at a 25% density produced a 1,099% increase in yield, a 46% increase in return and a 62% increase in profit. Such results decrease the low-density area needed to compensate for higher-density plantings for weed suppression. By contrast, soybean crops exhibited a one-to-one ratio for the same measures, regardless of planting density.

Using the optimization model recommended by the research team, it is possible to adopt variable planting strategies at a large scale – increasing weed suppression while maintaining or even reducing costs. The key is to balance denser plantings in areas where weeds have been identified with lower-density plantings in areas known to be weed-free or at lower risk.

Want to learn more? You can read the open access article here: “Crop physiological considerations for combining variable-density planting to optimize seed costs and weed suppression”

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