The Potential of Multi-Species Mixtures to Diversify Cover Crop Benefits

Cover crops provide a range of well-documented benefits to growers and the environment. However, no single species can deliver all of these benefits, and hence planting mixtures is gaining increasing attention. To the best of our knowledge, there is no comprehensive review on different multi-mix strategies. This article reviews available studies on multi-mixes, focusing on temperate North America, and discusses objective criteria for selecting components of a multi-mix and what future research is needed. Very few peer-reviewed studies on multi-mixes are currently available; a diversity of species compositions is being tested with a wide range of potential benefits but also with various limitations. Selection of species in multi-mixes is based on different criteria that help improve multiple ecosystem services. An emerging concept is the importance of selecting cover crop species with functional complementarity rather than simply increasing the number of species. Based on this concept, objective criteria have been developed to select the species for a multi-mix: grower objectives/primary purpose of planting the cover crop, crop rotation and cropping system compatibility, above and belowground compatibility, complementarity of different ecosystem functions, compatibility with the growing environment, duration for cover crop growth, termination option(s) available, input/labour costs, planting equipment required, persistence/weediness, and potential net economic returns. We propose a step-wise procedure to develop effective multi-species mixtures. The number of species and their ratio in the mixtures will depend on objective criteria, and hence long-term research is required to assess different species compositions and their impacts.

Download Full-text

Functional Diversity Of Interseeded Cover Crops And Their Effect On Carabid Activity-Density In Semi-Arid Climates

10.31237/osf.io/85pfw ◽

2020 ◽

Author(s):

Sara Capitan

Keyword(s):

Cover Crops ◽

Cover Crop ◽

Single Species ◽

Predation Rate ◽

Crop Diversity ◽

Environmental Benefits ◽

Crop Species ◽

Annual Crops ◽

Seeding Method ◽

Activity Density

Interseeding cover crops into standing annual crops can promote environmental benefits within agroecosystems. However, seeding method and cover crop diversity may influence biomass production and activity-density of ground beetles (Coleoptera: Carabidae). Carabids abundant in agroecosystems and their granivorous behavior can impact weeds and potentially crops. In a two-year study, six annual cover crop species– planted as either single species or mixtures– were interseeded into standing corn. The seed predation rate of Harpalus, a granivorous carabid, was estimated in a no-choice experiment using weed and crop seed species. Higher crop diversity did not correlate with biomass yield, but cover crop species did. Carabid activity-density was significantly higher later in the season, but was not influenced by diversity or species. Harpalus consumed crop seeds, but preferred weed seed. With further experimentation and analysis, these results can inform farmers in choosing the most effective seeding method and seed type for interseeded cover crop establishment.

Download Full-text

Characterization of Cover Crop Rooting Types from Integration of Rhizobox Imaging and Root Atlas Information

Plants ◽

10.3390/plants8110514 ◽

2019 ◽

Vol 8 (11) ◽

pp. 514 ◽

Cited By ~ 2

Author(s):

Bodner ◽

Loiskandl ◽

Hartl ◽

Erhart ◽

Sobotik

Keyword(s):

Data Integration ◽

Root System ◽

Cover Crops ◽

Cover Crop ◽

Plant Root ◽

Large Diameter ◽

Ecosystem Functions ◽

Distribution Data ◽

Species Classification ◽

Crop Species

Plant root systems are essential for sustainable agriculture, conveying resource-efficient genotypes and species with benefits to soil ecosystem functions. Targeted selection of species/genotypes depends on available root system information. Currently there is no standardized approach for comprehensive root system characterization, suggesting the need for data integration across methods and sources. Here, we combine field measured root descriptors from the classical Root Atlas series with traits from controlled-environment root imaging for 10 cover crop species to (i) detect descriptors scaling between distant experimental methods, (ii) provide traits for species classification, and (iii) discuss implications for cover crop ecosystem functions. Results revealed relation of single axes measures from root imaging (convex hull, primary-lateral length ratio) to Root Atlas field descriptors (depth, branching order). Using composite root variables (principal components) for branching, morphology, and assimilate investment traits, cover crops were classified into species with (i) topsoil-allocated large diameter rooting type, (ii) low-branched primary/shoot-born axes-dominated rooting type, and (iii) highly branched dense rooting type, with classification trait-dependent distinction according to depth distribution. Data integration facilitated identification of root classification variables to derive root-related cover crop distinction, indicating their agro-ecological functions.

Download Full-text

Assessment of Cover Crop Management Strategies in Nebraska, US

Agriculture ◽

10.3390/agriculture9060124 ◽

2019 ◽

Vol 9 (6) ◽

pp. 124 ◽

Cited By ~ 5

Author(s):

Maxwel C. Oliveira ◽

Liberty Butts ◽

Rodrigo Werle

Keyword(s):

Cover Crops ◽

Cover Crop ◽

Management Strategies ◽

Crop Management ◽

Weed Suppression ◽

Future Research ◽

Weed Species ◽

Crop Species ◽

Seed Corn ◽

Field Corn

Adoption of cover crops has the potential to increase agricultural sustainability in the US and beyond. In 2017, a survey was conducted with Nebraska stakeholders in an attempt to evaluate current cover crop management strategies adopted in soybean (Glycine max [L.] Merr.), field corn (Zea mays L.), and seed corn production. Eighty-two Nebraska stakeholders answered the survey, of which 80% identified themselves as growers. Eighty-seven percent of respondents manage cover crops, and the average cover crop ha planted on a per farm basis is 32%. The primary method of establishing cover crops following soybeans and field corn is drilling. In seed corn, interseeding is the main seeding strategy for cover crop establishment. Cereal rye (Secale cereale L.) appeared as the most adopted cover crop species (either alone or in mixtures with radish [Raphanus sativus L.] or hairy vetch [Vicia villosa Roth]). Over 95% of respondents utilize herbicides for cover crop termination in the spring before crop planting. Glyphosate is used by 100% of survey respondents that use herbicides for cover crop termination. The major observed impacts of incorporating cover crops into a production system according to survey respondents are reduced soil erosion and weed suppression. According to 93% of respondents, cover crops improve weed control by suppressing winter and/or summer annual weed species. The biggest challenge reported by cover crop adopters is planting and establishing a decent stand before winter. According to the results of this survey, there are different management strategies, positive outcomes, and challenges that accompany cover crop adoption in Nebraska. These results will help growers, agronomists, and researchers better guide cover crop adoption, management, and future research and education needs in Nebraska and beyond.

Download Full-text

Arthropod Granivory of Lime-Coated Cover Crop Seeds

Environmental Entomology ◽

10.1093/ee/nvaa053 ◽

2020 ◽

Vol 49 (4) ◽

pp. 848-853

Author(s):

Michael M Bredeson ◽

Dwayne Beck ◽

Jonathan G Lundgren

Keyword(s):

Calcium Carbonate ◽

Plant Species ◽

Cover Crops ◽

Cover Crop ◽

Alternative Methods ◽

Ecosystem Functions ◽

Seed Coating ◽

Field Exposure ◽

Crop Species ◽

Crop Seed

Abstract Diversifying cropland plant communities is prerequisite to restoring ecosystem functions in agricultural habitats. Cover crops are one such way to improve biodiversity, and broadcasting calcium carbonate-coated (lime) seeds can be a viable method for plant establishment. In addition to improving seed-to-soil contact, calcium carbonate may also reduce arthropod granivory. Here we examine the effect of this seed-coating technology on arthropod granivory for seven cover crop species under field conditions. Carabidae, Gryllidae, and Staphylinidae were the three most frequently collected granivorous taxa in pitfall samples, and Pterostichus permundus and Gryllus pennsylvanicus represented 60.8% of all individual granivores. Cover crop seed damaged was variable among plant species. Among all plant species, the presence of a seed coating significantly reduced granivory by nearly 40% in the 7-d field exposure. Individually, hairy vetch and sorghum × sudan seeds were especially protected by calcium carbonate. No positive correlations were observed between invertebrate groups and the number of seeds consumed. Alternative methods for assessing the functionality of granivorous arthropod communities should be pursued, as activity-density measured from pitfall traps failed to reveal important cover crop seed consumers. Protection of cover crop seeds from granivory through a calcium carbonate coating may allow producers to adjust seeding rates and save on costs, increasing the rate of adoption for this conservation practice.

Download Full-text

Allelopathy in Cover Crop-based Production Systems

HortScience ◽

10.21273/hortsci.30.4.819a ◽

1995 ◽

Vol 30 (4) ◽

pp. 819A-819

Author(s):

N.G. Creamer ◽

M.A. Bennett ◽

J. Cardina ◽

E.E. Regnier

Keyword(s):

Cover Crops ◽

Cover Crop ◽

Production Systems ◽

Single Species ◽

Crop Species ◽

Eastern Black Nightshade ◽

Crimson Clover ◽

Water Ph ◽

Germinating Seeds ◽

Allelochemical Effects

Little research has been conducted to quantify allelopathic suppression of weeds in the field. The objectives of this study were to develop an adequate control for separating physical from allelochemical effects, use the control to quantify allelochemical suppression in the field, and determine whether a mixture of cover crops would provide a broader spectrum of weed control than single species. Hairy vetch, rye, crimson clover, and barley were cut into 5-cm pieces, shaken in distilled water (pH 6) to leach allelochemicals, and redried. A seed germination bioassay confirmed that leached cover crops were nontoxic to germinating seeds. Physical suppression of Eastern black nightshade by the four cover crop species occurred in the field study, as did allelochemical suppression by crimson clover. Only rye physically suppressed yellow foxtail, and none of the cover crops suppressed yellow foxtail allelochemically.

Download Full-text

Redistribution of phosphorus in soil through cover crop roots

Brazilian Archives of Biology and Technology ◽

10.1590/s1516-89132004000300007 ◽

2004 ◽

Vol 47 (3) ◽

pp. 381-386 ◽

Cited By ~ 13

Author(s):

Júlio C. Franchini ◽

Marcos A. Pavan ◽

Mário Miyazawa

Keyword(s):

Pisum Sativum ◽

Cover Crops ◽

Cover Crop ◽

Lupinus Albus ◽

Growth Period ◽

Soil Surface ◽

Phosphate Fertilizer ◽

Vicia Sativa ◽

Crop Species ◽

Soil P

The objective of this study was to evaluate if cover crops can absorb P from the upper layers and transport it in their roots to subsoil layers. Samples of an Oxisol were placed in PVC columns. Super phosphate fertilizer was applied to the 0-10 cm soil surface layers. The cover crops tested were: Avena strigosa, Avena sativa, Secale cereale, Pisum sativum subsp arvense, Pisum sativum, Vicia villosa, Vicia sativa, Lupinus angustifoliu, Lupinus albus, and Triticum aestivum. After a growth period of 80 days the cover crop shoots were cut off and the soil was divided into 10cm layers and the roots of each layer were washed out. The roots and shoots were analyzed separated for total P contribution to the soil. Considerable amount of P was present in the roots of cover crops. Vicia sativa contained more than 60% of total plant P in the roots. The contribution of Vicia sativa to soil P bellow the fertilized zone was about 7 kg ha-1. It thus appeared that there existed a possibility of P redistribution into the soil under no tillage by using cover crops in rotation with cash crops. Vicia sativa was the most efficient cover crop species as P carrier into the roots from superficial layer to lower layers.

Download Full-text

The influence of the seasons: how the agricultural calendar impacts farmer perceptions of cover crops

Renewable Agriculture and Food Systems ◽

10.1017/s1742170521000521 ◽

2021 ◽

pp. 1-11

Author(s):

Margaret Beetstra ◽

Robyn Wilson ◽

Eric Toman

Keyword(s):

Cover Crops ◽

Cover Crop ◽

Conservation Practice ◽

Individual Level ◽

Practice Adoption ◽

Wide Range ◽

Research Findings ◽

Time Of Year ◽

Conducting Research ◽

Conservation Practice Adoption

Abstract Across the Midwest, substantial funding and personnel time have been allocated to encourage farmers to adopt a wide range of conservation practices but adoption rates for many of these practices remain low. Prior research focuses largely on the influence of individual-level factors (e.g., beliefs, attitudes) on conservation practice adoption rather than on contextual factors (e.g., seasons) that might also play a role. In the present study, we considered seasonal variation and its potential influence on farmer cover crop decision-making. We first established how farmer temporal and financial resources fluctuate across the year and then compared the annual agricultural decision and cover crop decision calendars. We also considered farmer cover crop perceptions and likely behaviors. To study this, we surveyed the same Midwestern farmers in the spring, summer and winter within a 12-month period. Results indicated that farmers were generally the least busy and the most financially comfortable in the winter months. Moreover, farmers perceived the benefits of cover crops differently throughout the year. These results indicate that seasonality can be a confounding factor which should be considered when designing and conducting research and farmer engagement. As researchers, it is our responsibility to understand the specific calendar experienced by our sample and how that may influence responses so we can examine theory-supported factors of interest rather than seasonality as a driver of farmer responses. As practitioners, it is important to use research findings to engage with farmers about conservation in a way that prioritizes communicating about the most salient aspects of the practice at the time of year when farmers will be most receptive.

Download Full-text

Systemic Colonization by Metarhizium robertsii Enhances Cover Crop Growth

Journal of Fungi ◽

10.3390/jof6020064 ◽

2020 ◽

Vol 6 (2) ◽

pp. 64

Author(s):

Imtiaz Ahmad ◽

María del Mar Jiménez-Gasco ◽

Dawn S. Luthe ◽

Mary E. Barbercheck

Keyword(s):

Cover Crops ◽

Cover Crop ◽

Field Experiments ◽

Negative Relationship ◽

Crop Growth ◽

Above Ground Biomass ◽

Crop Species ◽

Metarhizium Robertsii ◽

Cereal Rye ◽

Ground Biomass

Fungi in the genus Metarhizium (Hypocreales: Clavicipitaceae) are insect pathogens that can establish as endophytes and can benefit their host plant. In field experiments, we observed a positive correlation between the prevalence of M. robertsii and legume cover crops, and a negative relationship with brassicaceous cover crops and with increasing proportion of cereal rye in mixtures. Here, we report the effects of endophytic M. robertsii on three cover crop species under greenhouse conditions. We inoculated seeds of Austrian winter pea (Pisum sativum L., AWP), cereal rye (Secale cereale L.), and winter canola (Brassica napus L.) with conidia of M. robertsii to assess the effects of endophytic colonization on cover crop growth. We recovered M. robertsii from 59%, 46%, and 39% of seed-inoculated AWP, cereal rye, and canola plants, respectively. Endophytic M. robertsii significantly increased height and above-ground biomass of AWP and cereal rye but did not affect chlorophyll content of any of the cover crop species. Among inoculated plants from which we recovered M. robertsii, above-ground biomass of AWP was positively correlated with the proportion of colonized root but not leaf tissue sections. Our results suggest that winter cover crops may help to conserve Metarhizium spp. in annual cropping systems.

Download Full-text

Cover crop species affect mycorrhizae-mediated nutrient uptake and pest resistance in maize

Renewable Agriculture and Food Systems ◽

10.1017/s1742170519000061 ◽

2019 ◽

Vol 35 (5) ◽

pp. 467-474 ◽

Cited By ~ 8

Author(s):

Ebony G. Murrell ◽

Swayamjit Ray ◽

Mary E. Lemmon ◽

Dawn S. Luthe ◽

Jason P. Kaye

Keyword(s):

Nutrient Uptake ◽

Cover Crops ◽

Cover Crop ◽

European Corn Borer ◽

Pest Resistance ◽

Plant Nutrient ◽

Crop Species ◽

Maize Crop ◽

Corn Borer ◽

Maize Growth

AbstractArbuscular mycorrhizal fungi (AMF) can increase plant nutrient uptake and chemical defense production, both of which can improve plants’ ability to resist insect herbivory. Cover crops—non-commercial species planted in between cash crops in a crop rotation—can naturally alter both soil nutrients and AMF. We tested whether different cover crop species alter AMF colonization, plant nutrient status and plant–insect interactions in a subsequent maize crop. Cover crop species were either non-mycorrhizal, non-leguminous (canola, forage radish), mycorrhizal non-leguminous (cereal rye, oats), mycorrhizal leguminous (clover, pea) or absent (fallow). We measured the cascading consequences of cover crop treatment on maize root AMF colonization, maize growth and performance of an herbivorous insect (European corn borer) feeding on the maize. Maize AMF colonization was greater in plots previously planted with mycorrhizal (rye, oats) than non-mycorrhizal (canola, radish) cover crops or no cover crop (fallow). AMF colonization was linked to increased plant phosphorous and nitrogen, and maize growth increased with low plant N:P. Induced jasmonic acid pathway plant defenses increased with increasing maize growth and AMF colonization. European corn borer survivorship decreased with lower plant N:P, and insect development rate decreased with increased induced plant defenses. Our data describe a cascade in which cover crop species selection can increase or decrease mycorrhizal colonization of subsequent maize crop roots, which in turn impacts phosphorus uptake and may affect herbivory resistance in the maize. These results suggest that farmers could select cover crop species to manage nutrient uptake and pest resistance, in order to amend or limit fertilizer and pesticide use.

Download Full-text

Cover Crop Effectiveness Varies in Cover Crop-Based Rotational Tillage Organic Soybean Systems Depending on Species and Environment

Agronomy ◽

10.3390/agronomy9060319 ◽

2019 ◽

Vol 9 (6) ◽

pp. 319 ◽

Cited By ~ 2

Author(s):

Laura Vincent-Caboud ◽

Léa Vereecke ◽

Erin Silva ◽

Joséphine Peigné

Keyword(s):

Cover Crops ◽

Weed Management ◽

Cover Crop ◽

Crop Yields ◽

Weed Suppression ◽

Future Research ◽

Weed Biomass ◽

Cereal Rye ◽

Cereal Grain ◽

Crop Biomass

Organic farming relies heavily on tillage for weed management, however, intensive soil disturbance can have detrimental impacts on soil quality. Cover crop-based rotational tillage (CCBRT), a practice that reduces the need for tillage and cultivation through the creation of cover crop mulches, has emerged as an alternative weed management practice in organic cropping systems. In this study, CCBRT systems using cereal rye and triticale grain species are evaluated with organic soybean directly seeded into a rolled cover crop. Cover crop biomass, weed biomass, and soybean yields were evaluated to assess the effects of cereal rye and winter triticale cover crops on weed suppression and yields. From 2016 to 2018, trials were conducted at six locations in Wisconsin, USA, and Southern France. While cover crop biomass did not differ among the cereal grain species tested, the use of cereal rye as the cover crop resulted in higher soybean yields (2.7 t ha−1 vs. 2.2 t ha−1) and greater weed suppression, both at soybean emergence (231 vs. 577 kg ha−1 of weed biomass) and just prior to soybean harvest (1178 vs. 1545 kg ha−1). On four out of six sites, cover crop biomass was lower than the reported optimal (<8000 kg ha−1) needed to suppress weeds throughout soybean season. Environmental conditions, in tandem with agronomic decisions (e.g., seeding dates, cultivar, planters, etc.), influenced the ability of the cover crop to suppress weeds regardless of the species used. In a changing climate, future research should focus on establishing flexible decision support tools based on multi-tactic cover crop management to ensure more consistent results with respect to cover crop growth, weed suppression, and crop yields.

Download Full-text