Study Initiated on Cover Crops in Corn and Soybean Systems

Study Initiated on Cover Crops in Corn and Soybean Systems April 17, 2015

2015 Research Update

Cover crops have been described as the "newest old concept" in farming. While this addition is not an entirely new idea, the number of farmers integrating cover crops into their cropping systems continues to increase.

Some of the reasons farmers incorporate cover crops into their systems are to increase soil organic matter, reduce soil erosion, alleviate soil compaction, improve weed control, and provide a nitrogen source. While all these results are possible, realizing such benefits can be challenging. The added labor and cost, potential for nitrogen tie-up, and depletion of water needed for the cash crop are a few of the potential cover crop pitfalls.

Researchers at UNL are working on a new study funded by the Nebraska Corn Board and Nebraska Soybean Board to investigate the effects of integrating cover crops into soybean and corn cropping systems. The team working on the project includes researchers in Lincoln, Concord, Clay Center, and North Platte with expertise in cropping systems, soil fertility, soil physics, weed science, agroecology, and ag economics.

One of the group's primary objectives is to determine how cover crops could affect corn and soybean yields under a range of cropping and weather conditions.

The study is being conducted at two rain-fed (Mead and Concord) and two irrigated (Clay Center and Brule) sites. Three crop rotations (corn following corn, corn following soybean, and soybean following corn), two seeding dates (corn at R5-dent and post-harvest), and five cover crop treatments are being tested (Table 1). For fall 2014, the R5 planting was broadcast mid-September and the post-harvest planting was drilled about one month later in mid-October. The cover crops surviving the winter will be terminated two weeks prior to corn planting this spring.

To determine the effect of cover crops on corn and soybean cropping systems, and especially how grain yields are impacted, soil moisture monitoring, cover crop biomass production and nutrient sequestration, and corn and soybean development will be measured. In addition, a number of soil chemical, physical, and biological properties will be measured to study the potential benefit cover crops have over three years. This includes both yields and economic pay-offs.

While we are still early in the study, our plans to communicate findings are underway. Please follow CropWatch for field day announcements. We will also present annual updates at UNL Crop Production Clinics.

Chris Proctor, Roger Elmore, Humberto Blanco, Chuck Francis, Charles Shapiro, Richard Ferguson, Tim Shaver, all in the Department of Agronomy and Horticulture
Derek Heeren, Department of Biological Systems Engineering
Matt Stockton, Department of Agricultural Economics

Table 1. Cover crop study treatments at four Nebraska locations.
Location Rain-fed
Mead and Concord
Rotation Corn fb1 Corn Corn fb Soybean Soybean fb Corn
Planting R5-Dent
(broadcast)
Post-harvest
(drill)
R5-Dent
(broadcast)
Post-harvest
(drill)
R5-Dent
(broadcast)
Post-harvest
(drill)
Cover Crops Grass2, legume3, brassica4, 4-way mix5, 7-species cocktail6, control
Location Irrigated
Clay Center and Brule
Rotation Corn fb1 Corn Corn fb Soybean Soybean fb Corn
Planting R5-Dent
(broadcast)
Post-harvest
(drill)
R5-Dent
(broadcast)
Post-harvest
(drill)
R5-Dent
(broadcast)
Post-harvest
(drill)
Cover Crops Grass2, legume3, brassica4, 4-way mix5, 7-species cocktail6, control
1 Followed by (fb)
2 Grass: cereal rye ‘elbon'
3 Legume: hairy vetch ‘vallana', winter pea ‘variety not stated (vns)'
4 Brassica: oilseed radish ‘nitro'
5 Four-way-mix: cereal rye ‘elbon', hairy vetch ‘vallana', winter pea ‘vns', oilseed radish ‘nitro'
6 Seven-species-cocktail: cereal rye ‘elbon', black oat ‘cosaque', hairy vetch ‘vallana', winter pea ‘vns', balansa clover ‘vns', oilseed radish ‘nitro', forage collards ‘impact'

 

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