Instead of terminating a cover crop prior to no-tilling corn, soybeans or another crop, more growers are planting through a still growing green cover crop. Seeding a cash crop into a growing green cover crop that may range in height from just a few inches to over 6 feet tall allows both crops to grow longer in the spring.

The idea behind “planting green” is to make better use of spring moisture, reduce soil erosion, be able to graze cover crops in the spring, build more root biomass in the soil, improve weed control and increase fertility along with a number of other benefits.

Growing Interest

In the first-ever Cover Crop Benchmark Study conducted in 2020 for our Cover Crop Strategies publication, 48% of growers had planted cash crops into a living cover crop. When planting green, 70% had planted soybeans, 51% corn for grain, 8% corn for silage and 4% winter wheat.

Our results were very similar to those of growers who participated in the 2020 cover crop survey sponsored by USDA’s Sustainable Agriculture Research and Education group and the Conservation Technology Information Center. In this survey, which included growers using all tillage practices, 52% of the growers had planted green during the year. Some 26% planted two-thirds of their summer crops into a green cover crop. Yet 23% planted less than 20% of their acreage into green cover crops.

About one-third of these growers indicated planting green made management simpler while another one-third felt it was more complex compared to more typical cover crop termination. Another 20% felt planting green made management more difficult, but they still believed the benefits outweighed the challenges. However, 16% weren’t sure whether they would risk planting green again.

Improved weed control was a benefit for 71% while only 4% saw worse weed control. Some 68% saw more available soil moisture while 54% said it let them plant sooner. A few growers felt planting green provided a more uniform seedbed, resulted in less mud or moisture problems at planting and led to better crop emergence.

No Yield Boosts

In 2020, University of Nebraska agronomists asked farmers about their planting green experiences. Some 53% said they had planted corn into a green cover crop less than 10 inches tall. Most saw no yield increase or less than 5 bushels per acre.

Some 14% of these growers saw an allelopathic effect from planting green while an increase in corn pests was observed by 13% of the growers. Two-thirds of the growers saw no delay in corn emergence while 62% saw increased soil water usage and soil fertility was improved in 39% of the cases.

While slightly more than half of these growers planted soybeans into a green cover crop, most saw no increase or less than a 5 bushel per acre boost in bean yields. Some 63% reported soil water increases and 61% saw no impact on soil fertility.