Evaluation of Diverse Cover Crops Across Nebraska: Findings from Spring-planted Cover Crops in 2022

Evaluation of Diverse Cover Crops Across Nebraska: Findings from Spring-planted Cover Crops in 2022


The Cover Crop Initiative is a four-year collaborative effort with the University of Nebraska-Lincoln (UNL) and Nebraska Natural Resources Conservation Service (NRCS) to learn about and promote the strategic utilization of cover crops in Nebraska. Specifically, the project establishes cover crop variety trials in multiple Nebraska ecoregions, at several UNL research stations. This project hopes to provide knowledge and skills training to NRCS, as well as other internal and external stakeholders on implementing site-specific cover crop projects designed to achieve specific management goals. Data collected will be integrated into an online portal aggregating science and experiment-based information to connect soil health and the strategic use of cover crops in Nebraska. Online information includes cover crop production estimates utilizing Nebraska-specific climate and soils information, as well as the specific information about the species selected.

Cover cropping is a widely recognized agricultural conservation practice that has been shown to improve soil health, productivity and biodiversity. It has the potential to address several issues in Nebraska, including soil erosion, nutrient management and weed suppression, as well as to serve as a cropland-livestock integration mechanism. Cover crop success, however, is dependent on the selection of appropriate cover crop species, as adaptation of different cover crop species determines its performance in achieving the specific goals of conservation and management. It is also important to note that performance differences can exist within the same species beyond environmental factors, including the specific plant hardiness zone and the local landscape.

Nebraska's annual precipitation varies greatly from west to east, ranging from 13 to 35 inches (Figure 1). This variation in precipitation, combined with the state's diverse cropping systems, soils and climate, highlights the need for a tailored approach to cover crop species selection. It is critical to select the most appropriate cover crop species or variety that is well-suited to the unique eco-region and able to achieve specific management goals, based on locally derived data and information on the species-specific capabilities and tolerances.

Cover Crop Variety Trial

The project’s cover crop variety trials are located at five UNL research stations across the state: Panhandle Research Extension and Education Center (PHREEC), Scottsbluff; High Plains Ag Lab (HPAL) near Sidney; West Central Research Extension and Education Center (WCREEC), North Platte; Rogers Memorial Farm (RMF) near Lincoln; and Haskell Ag Lab (HAL), Concord (Figure 1).

At all the project study locations, the experimental layout is a randomized complete block design (RCBD) with four replications. Cover crop planting windows are spring (March-May), summer (June-October), and fall/winter (October-April of following year). The types of cover crop species evaluated based on location and growing window are listed in Table 1. Performance of different cover crop species and varieties were evaluated by monitoring growth and other characteristics listed on Table 2.

Cover crop variety trial site map
Figure 1. Map showing the distribution of study sites across the precipitation gradients. Study sites are represented as “black stars” on the map. Each colored region on the map represents the precipitation range as presented on the map legend. Precipitation data from 1981-2010 were collected from High Plains RCC CLIMOD.
Table 1
Table 1. 2022 sites and planting windows.
SiteGrowing WindowSpecies
HPAL, Sidney March 4 to May 25 Cool-season small grains, legumes, brassicas, mixes
PHREEC, Scottsbluff March 23 to May 24 Cool-season small grains, legumes, brassicas, mixes
WCREEC, North Platte June 20 to Sept. 19 Warm-season grasses, legumes, brassicas, broadleaves, mixes
RMF, Lincoln July 12 to Oct. 11 Warm-season grasses, legumes, brassicas, broadleaves, mixes
HAL, Concord Sept. 10 to spring 2023 Cool-season small grains, legumes, brassicas, mixes
PHREEC, Scottsbluff Sept. 16 to spring 2023 Cool-season small grains, legumes, brassicas, mixes
WCREEC, North Platte Sept. 30 to spring 2023 Cool-season small grains, legumes, brassicas, mixes
Table 2
Table 2. Cover crop objectives and how they are measured.
Establishment Plant height and stand counts four weeks after planting (WAP)
Growth Growth stages at 4 WAP
Biomass quantity Dry matter at termination
Biomass quality (C:N ratio) Dry matter % C and % N
Forage quality NIRS analysis in fresh biomass
N benefits % N in dry matter

Adaptation and Performance Evaluation: Spring Season Cover Crops

Spring cover crops are typically short-season annual species and generally remain in the ground for about 60-90 days before cash crop planting. They are planted during the onset of spring when soil temperature is just warm enough for germination (~40℉). Spring cover crops can be planted in early March and terminated in late May, before planting cash crops like corn, dry edible beans, soybeans, barley, sugarbeets or sorghum. Spring planted cover crops provide different opportunities for species selection compared to winter cover crops.

The spring cover crops trials for 2022 were established at HPAL near Sidney and PHREEC at Scottsbluff, and planted on March 4, 2022, and March 23, 2022, respectively. Cover crops were terminated on May 24 and 25, 2022. A total of 20 species, varieties and mixes were evaluated including: grasses (seven), legumes (four), brassicas (three), two-way mixes (three), and three-way mixes (three). Species name, variety and seeding rates for all cover crop species are listed in Table 3. Site information and management details are provided in Table 4.

Table 3
Table 3. Cover crop type, species, variety and seeding rates as used for spring cover crops at Sidney and Scottsbluff in 2022.
TypeSpeciesVarietySeeding Rate (lbs./acre)
1 Spring forage barley Lavina 100
2 Spring barley Robust 100
3 Winter barley P919 100
4 Spring oats Goliath 100
5 Spring oats Hayden 100
6 Spring oats Jerry 100
7 Spring triticale Surge 100
8 Spring pea 4010 70
9 Winter pea Survivor 70
10 Winter pea WyoWinter 70
11 Faba bean Petite 70
12 Rapeseed Bonar 8
13 Rapeseed Barsica 8
14 Collard Impact 8
Two-way mixtures
15 Oat + Pea Goliath + 4010 Each species is ½ of its full rate
16 Oat + Pea Hayden + 4010 "
17 Triticale + Pea Surge + 4010 "
Three-way mixtures
18 Barley+Pea+Rapeseed Lavina+4010+Barsica Each species is 1/3 of its full rate
19 Oat + Pea + Rapeseed Goliath + 4010 + Barsica "
20 Triticale + Pea + Rapeseed Surge + 4010 + Barsica "
Table 4
Table 4. Management details for spring cover crops at Sidney and Scottsbluff in 2022.
Cooperator/site HPAL/Cheyenne County PHREEC/Scottsbluff County
Soil type Keith silt loam Tripp very fine sandy loam
Planting date March 4, 2022 March 23, 2022
Seeding depth 1 inch 1.25 inches
Soil moisture at planting Fairly dry Adequate at seeding depth
Implement/tools DCS research drill DCS research drill
Rows/plot 6 6
Row spacing 10 inches 10 inches
Plot length 30 feet 30 feet
Alley width 3 feet 3 feet
Tillage No-till No-till
Previous crop Sunflower Corn
Pre-plant herbicide Fall glyphosate (32 oz) Fall glyphosate (32 oz)
Fertilizer at planting None None
Irrigation Non-irrigated Non-irrigated
Total precipitation during growing period 3.7 inches 3.9 inches
Termination date May 25, 2022 May 24, 2022
Termination herbicide Sharpen (0.6 L ha-1) Glyphosate (0.38 L ha-1) Sharpen (0.6 L ha-1) Glyphosate (0.38 L ha-1)


Jerry oats, Pea4010 spring peas, and a mixture of Hayden oats and Pea4010 spring peas produced the highest biomass at Sidney, greater than 0.5 ton of biomass per acre (Figure 2A). There were no significant differences in biomass among cover crop varieties at Scottsbluff, although many species, including the grasses and legumes, produced approximately 0.3 tons per acre of biomass (Figure 2B). Collard (Impact) failed to establish, and Rapeseed (Barsica and Bonar) had very little growth at both Sidney and Scottsbluff (Figure 2). The three-week delay in planting reduced biomass production for most cover crop species at Scottsbluff compared to Sidney.

Figure 2. Spring cover crop biomass at the time of termination at Sidney (A) and Scottsbluff (B) in 2022. Different lowercase letters above bars indicate a significant difference between varieties within a species (p = 0.05, Fisher’s protected least significant difference (LSD) test).


  • Spring planted cover crops offer a different planting window alternative to late fall planting and can allow for successful establishment and production depending on location and growing time.
  • Lavina barley, Jerry oats, Pea4010 spring pea, and a two-way mix of Hayden oats and Pea4010 spring pea performed well in terms of biomass production and establishment within the local factors experienced at these western Nebraska locations and 80-plus days of growth.
  • Collard and rapeseeds did not perform or establish well within this planting window and local factors experienced at these western Nebraska locations.
  • Delayed planting by three weeks at Scottsbluff reduced biomass production for most species primarily due to the decreased growing time of 62 days vs 81 growing days at Sidney, except Goliath oats with an observed greater production amount, but not with statistical confidence.

Sidney cover crop field
Figure 3. Cover crop variety trial at Sidney, Nebraska.
Jerry oat cover crop
Figure 4. Jerry oat cover crop.
Spring pea cover crop
Figure 5. Pea4010 spring pea cover crop.

Hayden oat and pea cover crop
Figure 6. Hayden oat and Pea4010 cover crop.
Surge triticale cover crop
Figure 7. Surge triticale cover crop.
Robust barley cover crop
Figure 8. Robust barley cover crop.

Extension and Outreach Activities

Growers are invited to visit the following sites to learn more about these cover crop variety experiments:

  • Spring cover crop trials for 2023 will be repeated with the same treatment applications on new field locations at Sidney, Nebraska and Scottsbluff, Nebraska.
  • Spring trials will be on display during field days on May 9, 2023, at Scottsbluff, Nebraska, and June 14, 2023, at Sidney, Nebraska.
  • Fall cover crops interseeded into irrigated corn will be showcased during a field day on May 2, 2023, at Haskell Ag Lab, Concord, Nebraska.

For more project outputs, visit the CropWatch Variety Testing page.

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