Spring planting delays may cause some farmers to make adjustments to improve yields

COLUMBUS, Ohio – Heavy rains and wet fields across the region that have delayed planting have some farmers questioning whether they should swap out their full-season varieties with early-maturing ones that will produce crops in a shorter period of time.

That depends, says Laura Lindsey, a field crops expert with The Ohio State University College of Food, Agricultural, and Environmental Sciences (CFAES). Lindsey, a soybean and small grains specialist with Ohio State University Extension, CFAES’ outreach arm, said for both corn and soybean, timely planting is important to maximize yield.

In CFAES soybean trials, yields have decreased as much as a 0.5 bushels per acre for each day planted after the end of April, she said. 

Similarly, for corn, yield can decrease up to 1.75 bushels per acre for each day planted after the end of April, according to Osler Ortez, a CFAES assistant professor and an OSU Extension corn and emerging crop production systems specialist.

“However, although early planting is important, planting into good soil conditions is also very important, especially for corn due to its lower compensation capacity,” Ortez said in a recent CORN newsletter post. “In general, timely planting is important, but crops planted past the recommended planting window (early May) can still yield well, depending on weather conditions later in the growing season.

“Planting under poor conditions can be detrimental to crop yields.”

Some Ohio farmers face these questions as rainy and wet conditions have resulted in saturated soils conditions, which have delayed corn and soybean planting for some growers in some parts of the region.

Farmers reported fieldwork and planting was slow with the intermittent rain showers last week, leaving 2.5 days suitable for fieldwork, Ben Torrance, Ohio State statistician of the U.S. Department of Agriculture’s National Agricultural Statistics Service, said in a written statement.

Across Ohio, as of the week ended May 19, only 46 percent of corn was planted, according to the agency. That compares to 55 percent that had been planted by the same time last year and 44 percent that had been planted on average during the same time period over the past five years, the agency said.

During the same time period, only 41 percent of soybeans was planted, according to the agency. That compares to 53 percent that had been planted by the same time last year and 35 percent that had been planted on average during the same time period over the past five years, the agency said.

However, if corn planting is delayed, farmers can consider some adjustments, such as targeting plant population and seeding rates, OSU Extension agronomists recommended in a recent CORN newsletter post.

Depending on the corn hybrid and production environment, recommended plant populations can range from 26,000 to 34,000 plants per acre. Factoring in germination and emergence losses is necessary when estimating seeding rates.

Other recommendations include:

• When planting corn late, consider shorter season hybrids that will reach physiological maturity before the first killing frost. When soybeans are planted in May, 100,000 to 120,000 plants per acre is recommended as the target plant population. If soybean planting is delayed to June, the recommended target population increases to 130,000 to 150,000 plants per acre.
• Plant soybean in narrow rows (7.5 to 15-inches). The later in the growing season soybeans are planted, the greater the yield increase due to narrow rows.
• When planting soybeans late, the ‘rule of thumb’ is to plant the latest maturing variety that will reach physiological maturity before the first killing frost.

To make their planting decisions, growers can find more information in the Corn Newsletter, which offers weekly crop observations, related information, and appropriate recommendations for Ohio crop producers and industry and is produced by the Ohio State University Extension Agronomy Team.