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Are cover crop mixtures better at suppressing weeds than cover crop monocultures?

Published online by Cambridge University Press:  28 January 2020

Richard G. Smith
Associate Professor, Department of Natural Resources and the Environment, University of New Hampshire, Durham, NH, USA
Nicholas D. Warren
Research Scientist, Department of Natural Resources and the Environment, University of New Hampshire, Durham, NH, USA
Stéphane Cordeau
Research Scientist, Agroécologie, AgroSup Dijon, INRA, Université Bourgogne Franche-Comté, F-21000 Dijon, France
E-mail address:


Cover crops are increasingly being used for weed management, and planting them as diverse mixtures has become an increasingly popular strategy for their implementation. While ecological theory suggests that cover crop mixtures should be more weed suppressive than cover crop monocultures, few experiments have explicitly tested this for more than a single temporal niche. We assessed the effects of cover crop mixtures (5- or 6-species and 14-species mixtures) and monocultures on weed abundance (weed biomass) and weed suppression at the time of cover crop termination. Separate experiments were conducted in Madbury, NH, from 2014 to 2017 for each of three temporal cover-cropping niches: summer (spring planting–summer termination), fall (summer planting–fall termination), and spring (fall planting–subsequent spring termination). Regardless of temporal niche, mixtures were never more weed suppressive than the most weed-suppressive cover crop grown as a monoculture, and the more diverse mixture (14 species) never outperformed the less diverse mixture. Mean weed-suppression levels of the best-performing monocultures in each temporal niche ranged from 97% to 98% for buckwheat (Fagopyrum esculentum Moench) in the summer niche and forage radish (Raphanus sativus L. var. niger J. Kern.) in the fall niche, and 83% to 100% for triticale (×Triticosecale Wittm. ex A. Camus [Secale × Triticum]) in the winter–spring niche. In comparison, weed-suppression levels for the mixtures ranged from 66% to 97%, 70% to 90%, and 67% to 99% in the summer, fall, and spring niches, respectively. Stability of weed suppression, measured as the coefficient of variation, was two to six times greater in the best-performing monoculture compared with the most stable mixture, depending on the temporal niche. Results of this study suggest that when weed suppression is the sole objective, farmers are more likely to achieve better results planting the most weed-suppressive cover crop as a monoculture than a mixture.

Research Article
© Weed Science Society of America, 2020

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Associate Editor: Martin M. Williams II, USDA–ARS


Arbuckle, JG, Roesch-McNally, G (2015) Cover crop adoption in Iowa: the role of perceived practice characteristics. J Soil Water Conserv 70:418429CrossRefGoogle Scholar
Baraibar, B, Hunter, MC, Schipanski, ME, Hamilton, A, Mortensen, DA (2018) Weed suppression in cover crop monocultures and mixtures. Weed Sci 66:121133CrossRefGoogle Scholar
Bicksler, AJ, Masiunas, JB (2009) Canada thistle (Cirsium arvense) suppression with buckwheat or Sudangrass cover crops and mowing. Weed Technol 23:556563CrossRefGoogle Scholar
Blanco-Canqui, H, Shaver, TM, Lindquist, JL, Shapiro, CA, Elmore, RW, Francis, CA, Hergert, GW (2015) Cover crops and ecosystem services: insights from studies in temperate soils. Agron J 107:24492474CrossRefGoogle Scholar
Blesh, J, VanDusen, BM, Brainard, DC (2019) Managing ecosystem services with cover crop mixtures on organic farms. Agron J 111:826840CrossRefGoogle Scholar
Brainard, DC, Bellinder, RR, Kumar, V (2011) Grass-legume mixtures and soil fertility affect cover crop performance and weed seed production. Weed Technol 35:473479CrossRefGoogle Scholar
Bybee-Finley, KA, Mirsky, SB, Ryan, MR (2017) Crop biomass not species richness drives weed suppression in warm-season annual grass-legume intercrops in the Northeast. Weed Sci 65:669680Google Scholar
[CTIC] Conservation Technology Information Center (2017). Report of the 2016-17 National Cover Crop Survey. Joint Publication of the Conservation Technology Information Center, the North Central Region Sustainable Agriculture Research and Education Program, and the American Seed Trade Association. West Lafayette, IN: CTIC. 46 pGoogle Scholar
Couëdel, A, Alletto, L, Tribouillois, H, Justes, E (2018) Cover crop crucifer-legume mixtures provide effective nitrate catch crop and nitrogen green manure ecosystem services. Agric Ecosyst Environ 254:5059CrossRefGoogle Scholar
Creamer, NG, Bennett, MA, Stinner, BR (1997) Evaluation of cover crop mixtures for use in vegetable production systems. HortScience 32:866870CrossRefGoogle Scholar
Creamer, NG, Bennett, MA, Stinner, BR, Cardina, J, Regnier, EE (1996) Mechanisms of weed suppression in cover crop-based production systems. HortScience 31:410413CrossRefGoogle Scholar
Falquet, B, Gfeller, A, Pourcelot, M, Tschuy, F, Wirth, J (2015) Weed suppression by common buckwheat: a review. Environ Control Biol 53:16CrossRefGoogle Scholar
Fargione, J, Brown, CS, Tilman, D (2003) Community assembly and invasion: an experimental test of neutral versus niche processes. Proc Natl Acad Sci USA 100:89168920CrossRefGoogle ScholarPubMed
Finney, DM, Kaye, JP (2017) Functional diversity in cover crop polycultures increases multifunctionality of an agricultural system. J Appl Ecol 54:509517CrossRefGoogle Scholar
Finney, DM, White, CM, Kaye, JP (2016) Biomass production and carbon/nitrogen ratio influence ecosystem services from cover crop mixtures. Agron J 108:3952CrossRefGoogle Scholar
Florence, AM, Higley, LG, Drijber, RA, Francis, CA, Lindquist, JL (2019) Cover crop mixture diversity, biomass productivity, weed suppression, and stability. PLoS ONE 14:e0206195CrossRefGoogle ScholarPubMed
Freyre, R, Loy, JB (2000) Evaluation and yield trials of tomatillo in New Hampshire. HortTechnology 10:374377CrossRefGoogle Scholar
Fridley, JD (2003) Diversity effects on production in different light and fertility environments: an experiment with communities of annual plants. J Ecol 91:396406CrossRefGoogle Scholar
Groff, S (2008) Mixtures and cocktails: soil is meant to be covered. J Soil Water Conserv 63:110A111ACrossRefGoogle Scholar
Hayden, ZD, Brainard, DC, Henshaw, B, Ngouajio, M (2012) Winter annual weed suppression in rye-vetch cover crop mixtures. Weed Technol 26:818825CrossRefGoogle Scholar
Hodgdon, EA, Warren, ND, Smith, RG, Sideman, RG (2016) In-season and carry-over effects of cover crops on productivity and weed suppression. Agron J 108:16241635CrossRefGoogle Scholar
Hunter, MC, Smith, RG, Schipanski, ME, Atwood, LW, Mortensen, DA (2017) Agriculture in 2050: recalibrating targets for sustainable intensification. BioScience 67:386391CrossRefGoogle Scholar
Jiang, XL, Zhang, WG, Wang, G (2007) Biodiversity effects on biomass production and invasion resistance in annual versus perennial plant communities. Biodivers Conserv 16:19831994CrossRefGoogle Scholar
Kladivko, EJ, Kaspar, TC, Jaynes, DB, Malone, RW, Singer, J, Morin, XK, Searchinger, T (2014) Cover crops in the upper midwestern United States: potential adoption and reduction of nitrate leaching in the Mississippi River Basin. J Soil Water Conserv 69:279291CrossRefGoogle Scholar
Lawley, YE, Teasdale, JR, Weil, RR (2012) The mechanism for weed suppression by a forage radish cover crop. Agron J 104:110CrossRefGoogle Scholar
Lawley, YE, Weil, RR, Teasdale, JR (2011) Forage radish cover crop suppresses winter annual weeds in fall and before corn planting. Agron J 103:137144CrossRefGoogle Scholar
MacLaren, C, Swanepoel, P, Bennett, J, Wright, J, Dehnen-Schmutz, K (2019) Cover crop biomass production is more important than diversity for weed suppression. Crop Sci 59:733748CrossRefGoogle Scholar
Mohler, CL, Liebman, M (1987) Weed productivity and composition in sole crops and intercrops of barley and field pea. J Appl Ecol 24:685699CrossRefGoogle Scholar
Murrell, EG, Schipanski, ME, Finney, DM, Hunter, MC, Burgess, M, LaChance, JC, Baraibar, B, White, CM, Mortensen, DA, Kaye, JP (2017) Achieving diverse cover crop mixtures: effects of planting date and seeding rate. Agron J 109:259271CrossRefGoogle Scholar
Naeem, S, Knops, JMH, Tilman, D, Howe, KM, Kennedy, T, Gale, S (2000) Plant diversity increases resistance to invasion in the absence of covarying extrinsic factors. Oikos 91:97108CrossRefGoogle Scholar
Nelson, AG, Pswarayi, A, Quideau, S, Frick, B, Spaner, D (2011) Yield and weed suppression of crop mixtures in organic and conventional systems of the western Canadian Prairie. Agron J 104:756762CrossRefGoogle Scholar
Norsworthy, JK, Ward, SM, Shaw, DR, Llewellyn, RS, Nichols, RL, Webster, TM, Bradley, KW, Frisvold, G, Powles, SB, Burgos, NR, Witt, WW, Barrett, M (2012) Reducing the risks of herbicide resistance: best management practices and recommendations. Weed Sci 12(SP):3162CrossRefGoogle Scholar
Osipitan, OA, Dille, JA, Assefa, Y, Knezevic, SZ (2018) Cover crop for early season weed suppression in crops: systematic review and meta-analysis. Agron J 110:22112221CrossRefGoogle Scholar
Price, AJ, Balkcom, KS, Culpepper, SA, Kelton, JA, Nichols, RL, Schomberg, H (2011) Glyphosate-resistant Palmer amaranth: a threat to conservation tillage. J Soil Water Conserv 66:265275CrossRefGoogle Scholar
Ranells, NN, Wagger, MG (1997) Grass-legume bicultures as winter annual cover crops. Agron J 89:659665CrossRefGoogle Scholar
Schappert, A, Schumacher, M, Gerhards, R (2019) Weed control ability of single sown cover crops compared to species mixtures. Agronomy 9:294CrossRefGoogle Scholar
Smith, RG, Atwood, LW, Pollnac, FW, Warren, ND (2015) Cover crop species as distinct biotic filters in weed community assembly. Weed Sci 63:282295CrossRefGoogle Scholar
Smith, RG, Atwood, LW, Warren, ND (2014) Increased productivity of a cover crop mixture is not associated with enhanced agroecosystem services. PLoS ONE 9: e97351CrossRefGoogle Scholar
Snapp, SS, Swinton, SM, Labarta, R, Mutch, D, Black, JR, Leep, R, Nyiraneza, J, O’Neil, K (2005) Evaluating cover crops for benefits, costs and performance within cropping system niches. Agron J 97:322332Google Scholar
Storkey, J, Doring, T, Baddeley, J, Collins, R, Roderick, S, Jones, H, Watson, C (2015) Engineering a plant community to deliver multiple ecosystem services. Ecol Appl 25:10341043CrossRefGoogle ScholarPubMed
Teasdale, JR, Brandsaeter, LO, Calegari, A, Skora Neto, F (2007) Cover crops and weed management. Pages 4964in Upadhyaya, MK, Blackshaw, RE, eds. Non Chemical Weed Management Principles, Concepts and Technology. Wallingford, UK: CABICrossRefGoogle Scholar
Thapa, R, Poffenbarger, H, Tully, KL, Ackroyd, VJ, Kramer, M, Mirsky, SB (2018) Biomass production and nitrogen accumulation by hairy vetch-cereal rye mixtures: a meta-analysis. Agron J 110:11971208CrossRefGoogle Scholar
Tilman, D, Wedin, D, Knops, JMH (1996) Productivity and sustainability influenced by biodiversity in grassland ecosystems. Nature 379:718–20CrossRefGoogle Scholar
Tilman, D, Isbell, F, Cowles, JM (2014) Biodiversity and ecosystem functioning. Annu Rev Ecol Evol Syst 45:471493CrossRefGoogle Scholar
Tribouillois, H, Fort, F, Cruz, P, Charles, R, Flores, O, Garnier, E, Justes, E (2015) A functional characterization of a wide range of cover crop species: growth and nitrogen acquisition rates, leaf traits and ecological strategies. PLoS ONE 10:e0122156CrossRefGoogle Scholar
Wallace, JM, Curran, WS, Mortensen, DA (2019) Cover crop effects on horseweed (Erigeron canadensis) density and size inequality at the time of herbicide exposure. Weed Sci 67:327338CrossRefGoogle Scholar
Weisser, WW, Roscher, C, Meyer, ST, Ebeling, A, Luo, G, Allan, E, Beßler, H, Barnard, RL, Buchmann, N, Buscot, F, et al. (2017) Biodiversity effects on ecosystem functioning in a 15-year grassland experiment: patterns, mechanisms, and open questions. Basic Appl Ecol 23:173CrossRefGoogle Scholar
Weston, LA (1996) Utilization of allelopathy for weed management in agroecosystems. Agron J 88:860866CrossRefGoogle Scholar
Wiggins, MS, Hayes, RM, Steckel, LE (2016) Evaluating cover crops and herbicides for glyphosate-resistant Palmer amaranth (Amaranthus palmeri) control in cotton. Weed Technol 30:415422CrossRefGoogle Scholar
Wortman, SE, Francis, CA, Lindquist, JL (2012) Cover crop mixtures for the western Corn Belt: opportunities for increased productivity and stability. Agron J 104:699705CrossRefGoogle Scholar
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