Evaluation of Summer Cover Crops for Growth, Nutrient Dynamics, and Weed Suppression in South Florida
Source abstract
Abstract
Soil degradation, nutrient depletion, and persistent weed pressure represent critical challenges in the adoption of sustainable agriculture practices in subtropical organic farming systems. Reliance on conventional inputs threatens long-term soil health and ecosystem resilience, highlighting the need for regenerative alternatives. Cover crops are widely recognized as multifunctional agroecological tools with the capacity to enhance nutrient cycling, perform weed suppression, and improve soil organic matter. To evaluate their effectiveness in South Florida's subtropical climate and organic raised bed systems, a field experiment was conducted as a Randomized Block Design (RBD) at the Florida International University Organic Garden during the 2024 summer season. The six cover crops species that were tested include green gram (Vigna radiata), hibiscus (Hibiscus sabdariffa), sorghum (Sorghum bicolor), soybean (Glycine max), sunn hemp (Crotalaria juncea), and pearl millet (Pennisetum glaucum). Data collected includes plant establishment, biomass accumulation, weed suppression, soil physiochemical properties, and plant nutrient composition. Sorghum and sunn hemp produced the highest fresh and dry biomass, with sorghum achieving the most effective weed suppression with the lowest weed biomass and weed population. Sunn hemp contributed to enhanced nitrogen content in plant tissues, while hibiscus promoted the highest soil P and N concentrations. Pearl millet exhibited the highest total carbon and organic matter content, indicating potential for enhancing soil carbon content and soil fertility. Results show that each cover crop species can provide a specialized or generalized ecosystem service depending on management goals.
Source: crossref · Quality: baseline
Research context
OpenAlex topics: Agroforestry and silvopastoral systems · Agronomic Practices and Intercropping Systems · Weed Control and Herbicide Applications
SciVX discovery tags are terminology-based. OpenAlex topics are source-provided classifications.
Affiliations
Department of Earth and Environment, Florida International University, Miami, FL 33199, USA
Funding
USDA NRCS
References (75)
Show source-provided references
1. Cover cropping and conservation tillage improve soil health in the southeastern United States10.1002/agj2.20865 ↗
2. Wiener, S.S., Álvarez-Berríos, N.L., and Lindsey, A.B. (2020). Opportunities and challenges for hurricane resilience on agricultural and forest land in the U.S. Southeast and Caribbean. Sustainability, 12.10.3390/su12041364 ↗
3. Ma, J., Yin, B., Gao, T., He, K., Huang, X., Jiang, T., and Zhen, W. (2025). Legume–Non-Legume Cover Crop Mixtures Enhance Soil Nutrient Availability and Physical Properties: A Meta-Analysis Across Chinese Agroecosystems. Agronomy, 15.10.3390/agronomy15081756 ↗
4. The role of cover crops in improving soil fertility and plant nutritional status in temperate climates. A review10.1007/s13593-022-00825-0 ↗
5. Villat, J., and Nicholas, K.A. (2023). Quantifying soil carbon sequestration from regenerative agricultural practices in crops and vineyards. Front. Sustain. Food Syst., 7.10.3389/fsufs.2023.1234108 ↗
6. Zhang, K., Liu, Z., McCarl, B.A., and Fei, C.J. (2024). Enhancing agricultural soil carbon sequestration: A review with some research needs. Climate, 12.10.3390/cli12100151 ↗
7. Li, G., Ren, A., Anwar, S., Shi, L., Bai, W., Zhang, Y., and Gao, Z. (2024). Optimizing Soil Health and Sorghum Productivity through Crop Rotation with Quinoa. Life, 14.10.3390/life14060745 ↗
8. Dong, F., and Zeng, W. (2024). Effects of fall and winter cover crops on weed suppression in the United States: A meta-analysis. Sustainability, 16.10.3390/su16083192 ↗
9. Chaturvedi, P., Govindaraj, M., Govindan, V., and Weckwerth, W. (2022). Sorghum and pearl millet as climate resilient crops for food and nutrition security. Front. Plant Sci., 13.10.3389/fpls.2022.851970 ↗
10. Economics of cover crops10.1002/crso.20311 ↗
11. Delayed cover-crop termination and reduced herbicide inputs produce trade-offs in soybean phase of US Northeast forage-grain rotation10.1017/wet.2023.18 ↗
12. Bernier Brillon, J., Lucotte, M., Bernier, A., Fontaine, M., and Moingt, M. (2024). Using cover crops as means of controlling weeds and reducing the applied quantity of glyphosate-based herbicide in no-till glyphosate tolerant soybean and corn. Agriculture, 14.10.3390/agriculture14050659 ↗
13. Soil microbial strategies for climate mitigation—Report from a climate action workshop in Las Vegas, Nevada, February 202410.1093/sumbio/qvae033 ↗
14. Biswas, P., Mondal, S., Maji, S., Mondal, A., and Bandopadhyay, P. (2023). Microclimate modification in field crops: A way toward climate-resilience. Climate-Resilient Agriculture, Vol 1: Crop Responses and Agroecological Perspectives, Springer.10.1007/978-3-031-37424-1_29 ↗
15. Wallander, S., Smith, D., Bowman, M., and Claassen, R. (2021). Cover Crop Trends, Programs, and Practices in the United States, AgEcon Search.
16. Evaluation of vermicompost and vermicompost tea application on corn (Zea mays) growth and physiology using optical plant sensors10.1080/01904167.2024.2434583 ↗
17. Belbase, P., Jayachandran, K., and Balaji Bhaskar, M.S. (2025). Assessment of Soil and Plant Nutrient Status, Spectral Reflectance, and Growth Performance of Various Dragon Fruit (Pitaya) Species Cultivated Under High Tunnel Systems. Soil Syst., 9.10.3390/soilsystems9030075 ↗
18. National Weather Service (2026, May 05). National and Oceanic Atmospheric Administration, Available online: https://www.weather.gov/news.
19. Solly, E.F., Weber, V., Zimmermann, S., Walthert, L., Hagedorn, F., and Schmidt, M.W. (2020). A critical evaluation of the relationship between the effective cation exchange capacity and soil organic carbon content in Swiss forest soils. Front. For. Glob. Change, 3.10.3389/ffgc.2020.00098 ↗
20. Singh, M.S., and Devi, T.T. (2022). Field study on soil organic matter content in inundation areas of Langol Catchment by “loss-on-ignition” method. River Dynamics and Flood Hazards: Studies on Risk and Mitigation, Springer.10.1007/978-981-19-7100-6_21 ↗
21. Floating flowers: Screening cut-flower species for production and phytoremediation on floating treatment wetlands in South Florida10.1016/j.envadv.2023.100405 ↗
22. The role of different soil sample digestion methods on trace elements analysis: A comparison of ICP-MS and INAA measurement results10.1007/s00769-006-0238-1 ↗
23. Girden, E.R. (1992). ANOVA: Repeated Measures, Sage Publications. Chapter vi.10.4135/9781412983419 ↗
24. Comparing individual means in the analysis of variance10.2307/3001913 ↗
25. Cover crops improve soil condition and barley yield in a subtropical highland agroecosystem
26. Scianna, J., Zentner, D., Pokorny, M., Majeski, M., and Noack, R. (2026, May 05). Impact of Cover Crop Seeding Rate on Stand Establishment and Aboveground Biomass Production, Available online: https://www.nrcs.usda.gov/plantmaterials/mtpmcsr13926.pdf.
27. Bhandari, H., Shivakumar, K., Kar, C., Bera, A., and Meena, J. (2022). Sunn hemp: A climate-smart crop. Developing Climate Resilient Grain and Forage Legumes, Springer.10.1007/978-981-16-9848-4_13 ↗
28. Abiotic and biotic factors affecting crop seed germination and seedling emergence: A conceptual framework10.1007/s11104-018-3780-9 ↗
29. Stable characteristics of cover crops for weed suppression in organic farming systems10.1626/pps.14.75 ↗
30. The use of cover crop for weed suppression and competition in limited-irrigation vineyards10.1007/s12600-024-01124-y ↗
31. Florence, A., Higley, L.G., Drijber, R., Francis, C.A., and Lindquist, J.L. (2019). Cover crop mixture diversity, biomass productivity, weed suppression, and stability. PLoS ONE, 14.10.1371/journal.pone.0206195 ↗
32. Yield and weed suppression of crop mixtures in organic and conventional systems of the western Canadian prairie10.2134/agronj2011.0374 ↗
33. Do cover crops suppress weeds in the US Southeast? A meta-analysis10.1017/wsc.2023.21 ↗
34. Zannopoulos, S., Gazoulis, I., Kokkini, M., Antonopoulos, N., Kanatas, P., Kanetsi, M., and Travlos, I. (2024). The Potential of Three Summer Legume Cover Crops to Suppress Weeds and Provide Ecosystem Services—A Review. Agronomy, 14.10.3390/agronomy14061192 ↗
35. Cover crops improve soil structure and change organic carbon distribution in macroaggregate fractions10.5194/soil-10-139-2024 ↗
36. Biomass production, weed suppression, and soil water use of cover crops in dryland wheat production systems10.1002/agj2.70053 ↗
37. Cover crops and weed suppression in the US Midwest: A meta–analysis and modeling study10.1002/ael2.20022 ↗
38. Bilenky, M.T., Nair, A., and McDaniel, M.D. (2022). Effect of summer cover crops on cabbage yield, weed suppression, and N mineralization in a low input cropping system. Front. Sustain. Food Syst., 6.10.3389/fsufs.2022.1021639 ↗
39. Weed suppression in cover crop monocultures and mixtures10.1017/wsc.2017.59 ↗
40. Effect of fall-planted cover crops on weed suppression, grain sorghum yield, and profitability in the semiarid Central Great Plains10.1017/wsc.2024.100 ↗
41. A new approach for modelling weed suppression of cover crops10.1111/wre.12627 ↗
42. Explanations for Amaranthus retroflexus growth suppression by cover crops10.1016/j.cropro.2017.10.006 ↗
43. The importance of species selection in cover crop mixture design10.1017/wsc.2022.28 ↗
44. Zhang, H., Ghahramani, A., Ali, A., and Erbacher, A. (2023). Cover cropping impacts on soil water and carbon in dryland cropping system. PLoS ONE, 18.10.1371/journal.pone.0286748 ↗
45. Cover crop legacy impacts on soil water and nitrogen dynamics, and on subsequent crop yields in drylands: A meta-analysis10.1007/s13593-022-00760-0 ↗
46. Effect of tree canopy cover on soil moisture dynamics in different agroforestry systems under semi-arid condition10.9734/ijecc/2024/v14i94432 ↗
47. Using winter cover crops to improve soil and water quality10.1081/CSS-100104110 ↗
48. Freidenreich, A., Dattamudi, S., Li, Y., and Jayachandran, K. (2022). Influence of leguminous cover crops on soil chemical and biological properties in a no-till tropical fruit orchard. Land, 11.10.3390/land11060932 ↗
49. Shrestha, N., Hu, H., Shrestha, K., and Doust, A.N. (2023). Pearl millet response to drought: A review. Front. Plant Sci., 14.10.3389/fpls.2023.1059574 ↗
50. Pearl millet a promising fodder crop for changing climate: A review10.1007/s00122-024-04671-4 ↗
51. Cover crops alter soil physicochemical properties: A global meta-analysis10.1016/j.geoderma.2025.117436 ↗
52. Biological nitrogen fixation and soil N2O emissions from legume residues in an Acrisol in SE Brazil10.1016/j.geodrs.2018.e00196 ↗
53. Legume nitrogen credits for sugarcane production: Implications for soil N availability and ratoon yield10.1007/s10705-019-09979-y ↗
54. White, K.E., Brennan, E.B., Cavigelli, M.A., and Smith, R.F. (2022). Winter cover crops increased nitrogen availability and efficient use during eight years of intensive organic vegetable production. PLoS ONE, 17.10.1371/journal.pone.0267757 ↗
55. Three years of cover crops management increased soil organic matter and labile carbon pools in a subtropical vegetable agroecosystem10.1002/agg2.20454 ↗
56. Soil aggregation and potential carbon and nitrogen mineralization with cover crops under tropical no-till10.2489/jswc.2020.00188 ↗
57. Hidden miners–the roles of cover crops and soil microorganisms in phosphorus cycling through agroecosystems10.1007/s11104-018-3810-7 ↗
58. Unlocking the potential of plant growth-promoting rhizobacteria on soil health and the sustainability of agricultural systems10.1016/j.jenvman.2020.111118 ↗
59. Vermicompost derived from mushroom residues improves soil C/P cycling, bacterial community, and fungal abundance10.1111/gcbb.13103 ↗
60. Freidenreich, A. (2021). Developing Sustainable Soil Building Strategies for Tropical Fruit Groves within the South Florida Redland. [Ph.D. Dissertation, Florida International University].
61. Crop Residue Management for Soil Health and Environmental Sustainability: A Comprehensive Review10.1007/s42729-025-02633-3 ↗
62. Role of cover crops in improving soil and row crop productivity10.1080/00103620500303939 ↗
63. The role of cover crops towards sustainable soil health and agriculture—A review paper10.4236/ajps.2018.99140 ↗
64. Quintarelli, V., Radicetti, E., Allevato, E., Stazi, S.R., Haider, G., Abideen, Z., Bibi, S., Jamal, A., and Mancinelli, R. (2022). Cover crops for sustainable cropping systems: A review. Agriculture, 12.10.3390/agriculture12122076 ↗
65. Seepaul, R., George, S., Love, J., Wright, D., Mackowiak, C., and Blount, A. (2023). Managing Cover Crops for Improved Soil Health: SS-AGR-272/AG277, rev. 1/2023. Agronomy, 2023.10.32473/edis-ag277-2023 ↗
66. Cover plants can contribute on macronutrient accumulation in agroforestry systems during off-season10.1007/s10457-023-00849-9 ↗
67. Crops that feed the world 11. Pearl Millet (Pennisetum glaucum L.): An important source of food security, nutrition and health in the arid and semi-arid tropics10.1007/s12571-016-0557-y ↗
68. Ambati, K., and Sucharitha, K. (2024). Pearl Millet: Biology, Functional Potential and Sustainable Utilization: Major Millets. Millets: The Multi-Cereal Paradigm for Food Sustainability, Springer Nature. Available online: https://link.springer.com/chapter/10.1007/978-3-031-64237-1_4.10.1007/978-3-031-64237-1_4 ↗
69. Influence of root and leaf traits on the uptake of nutrients in cover crops10.1007/s11104-016-2974-2 ↗
70. Abo-Elyousr, K.A., Mousa, M.A., Ibrahim, O.H., Alshareef, N.O., and Eissa, M.A. (2022). Calcium-rich biochar stimulates salt resistance in pearl millet (Pennisetum glaucum L.) plants by improving soil quality and enhancing the antioxidant defense. Plants, 11.10.3390/plants11101301 ↗
71. Horneck, D.A., Ellsworth, J.W., Hopkins, B.G., Sullivan, D.M., and Stevens, R.G. (2007). Managing Salt-Affected Soils for Crop Production, Oregon State University Extension Service. Available online: https://ir.library.oregonstate.edu/concern/administrative_report_or_publications/pr76f371k.
72. Couëdel, A., Alletto, L., and Justes, E. (2023). The acquisition of macro-and micronutrients is synergistic in species mixtures: Example of mixed crucifer-legume cover crops. Front. Agron., 5.10.3389/fagro.2023.1223639 ↗
73. Review on iron availability in soil: Interaction of Fe minerals, plants, and microbes10.1007/s11368-013-0814-z ↗
74. Sensor-based prediction of cover crops biomass and nutrient recovery
75. Legumes in Cropping System for Soil Ecosystem Improvement: A Review