Systems management strategies for increasing alfalfa use in warm-humid regions

Abstract

Alfalfa use (Medicago sativa L.; “lucerne”) in warm, humid regions of the world represents a potential area of expansion for the alfalfa industry. The objective of this review paper is to demonstrate how alfalfa forage breeding and systems research efforts have identified opportunities for increasing alfalfa contributions in these regions, along with potential pathways for seed industry and farming operations to increase adoption. Our review draws primarily on reports from the Southeast United States and Argentina. Significant technological advancements in plant screening and selection have identified alfalfa plant populations that are more adapted to the growing conditions experienced in these regions, which are often characterized by mild temperature, long growing seasons, and multiple other abiotic and biotic stressors. Management systems research conducted in the United States and Argentina has demonstrated the use of alfalfa for conserved forage, grazing, or dual-purpose use in monoculture or mixtures with warm-season grasses such as bermudagrass (Cynodon spp.). These trials report increased forage production, nutritive value, and ecosystem services of alfalfa–grass mixtures when compared with traditionally N-fertilized warmseason grass-based systems. Grazing-based alfalfa systems in Argentina have demonstrated methods for utilizing alfalfa as part of beef, dairy, and finishing systems. Some approaches for expanding alfalfa production in the region include targeted marketing efforts for adapted varieties and demonstrating alfalfa applications within existing farming frameworks. This includes educational programming efforts and on-farm demonstrations to promote alfalfa use as a component of the livestock diets, integration into grass-based systems, crop rotations, and wildlife use. Continued emphasis on a systems approach to alfalfa inclusion represents an opportunity for improved forage and livestock production in warm, humid regions of the world.

Keywords

alfalfa / forage legumes / systems management

References

[1] Acharya, J. P., Lopez, Y., Gouveia, B. T., de Bem Oliveira, I., Resende, Jr., M. F. R., Muñoz, P. R., & Rios, E. F. (2020). Breeding alfalfa (Medicago sativa L.) adapted to subtropical agroecosystems. Agronomy, 10, 742.

[2] Adhikari, L., Makaju, S. O., & Missaoui, A. M. (2019). QTL mapping of flowering time and biomass yield in tetraploid alfalfa (Medicago sativa L.). BMC Plant Biology, 19, 359.

[3] Andrade, M. H., Acharya, J. P., Benevenuto, J., de Bem Oliveira, I., Lopez, Y., Muñoz, P., Resende, Jr., M. F. R., & Rios, E. F. (2022). Genomic prediction for canopy height and dry matter yield in alfalfa using family bulks. The Plant Genome, 15, 1–16.

[4] Annicchiarico, P. (2015). Alfalfa forage yield and leaf/stem ratio: Narrow-sense heritability, genetic correlation, and parent selection procedures. Euphytica, 205, 409–420.

[5] Annicchiarico, P., Nazzicari, N., Ananta, A., Carelli, M., Wei, Y., & Brummer, E. C. (2016). Assessment of cultivar distinctness in alfalfa: A comparison of genotyping-by-sequencing, simple-sequence repeat marker, and morphophysiological observations. The Plant Genome, 9, 1–12.

[6] Anonymous . (2022). Brazil creates its first Brachiaria ruziziensis grass cultivar. Embrapa Animal Production ICLFS. https://www.embrapa.br/en/busca-de-noticias/-/noticia/68876481/brazil-creates-its-first-brachiaria-ruziziensis-grass-cultivar#:∼:text=Cultivated%20in%20tropical%20regions%2C%20the,belong%20to%20the%20Brachiaria%20genus

[7] De Assis, G. M. L., Ruggieri, A. C., Mercadante, M. E. Z., De Camargo, G. M. F., & Carneiro Júnior, J. M. (2010). Selection of alfalfa cultivars adapted for tropical environments with repeated measures using PROC MIXED of SAS^® system. Plant Genetic Resources, 8, 55–62.

[8] Basigalup, D. (2023). Grazing management for alfalfa persistence and productivity. In R. Smith & T. Bowling (Eds.), In Proceedings of the XXV International Grassland Congress (pp. 419–424). Curran Associates, Inc.

[9] Basigalup, D., & Ustarroz, E. (2007). Graing alfalfa systems in the Argentinean Pampas. In Proceedings of the 37th California Alfalfa & Forage Symposium (pp. 53–62). University of California-Davis. https://alfalfasymposium.ucdavis.edu/+symposium/proceedings/2007/07-51.pdf

[10] Bates, G. E., Hoveland, C. S., McCann, M. A., Bouton, J. H., & Hill, N. S. (1996). Plant persistence and animal performance for continuously stocked alfalfa pastures at three forage allowances. Journal of Production Agriculture, 9, 418–423.

[11] Baxter, L. L., Burt, J. C., Mullenix, M. K., Payne, S. L., Reagin, K. R., Mason, K. M., Prevatt, C. G., & Tucker, J. J. (2023). Understanding the agronomic impacts of defoliation strategies in “Bulldog 805” alfalfa + “Tifton 85” bermudagrass mixed stands. Grassland Research, 2, 251–259.

[12] Beck, P., Hess, T., Hubbell, D., Gadberry, M. S., Jennings, J., & Sims, M. (2017a). Replacing synthetic N with clovers or alfalfa in bermudagrass pastures. 1. Herbage mass and pasture carrying capacity. Animal Production Science, 57, 539–546.

[13] Beck, P., Hess, T., Hubbell, D., Gadberry, M. S., Jennings, J., & Sims, M. (2017b). Replacing synthetic N with clovers or alfalfa in bermudagrass pastures. 2. Herbage nutritive value for growing beef steers. Animal Production Science, 57, 547–555.

[14] Beck, P., Hess, T., Hubbell, D., Gadberry, M. S., Jennings, J., & Sims, M. (2017c). Replacing synthetic N with clovers or alfalfa in bermudagrass pastures. 3. Performance of growing steers. Animal Production Science, 57, 556–562.

[15] Berone, G. D., Sardiña, M. C., & Moot, D. J. (2020). Animal and forage responses on lucerne (Medicago sativa L.) pastures under contrasting grazing managements in a temperate climate. Grass and Forage Science, 75, 192–205.

[16] Biazzi, E., Nazzicari, N., Pecetti, L., Brummer, E. C., Palmonari, A., Tava, A., & Annicchiarico, P. (2017). Genome-wide association mapping and genomic selection for alfalfa (Medicago sativa) forage quality traits. PLoS One, 12(1), e0169234.

[17] Biswas, A., Andrade, M. H. M. L., Acharya, J. P., de Souza, C. L., Lopez, Y., de Assis, G., Shirbhate, S., Singh, A., Munoz, P., & Rios, E. F. (2021). Phenomics-assisted selection for herbage accumulation in alfalfa (Medicago sativa L.). Frontiers in Plant Science, 12, 756768.

[18] Bouton, J. (2021). The irony and ecstasy of alfalfa in the south. Progressive Forage, 1, 20–21.

[19] Bouton, J. H. (2001). Alfalfa. In J. A. Gomide, W. R. S. Mattos, & S. C. Silva. (Eds.), In Proceedings of XIX International Grassland Congress. FEALQ. https://uknowledge.uky.edu/cgi/viewcontent.cgi?article=4439&context=igc

[20] Bouton, J. H. (2012a). An overview of the role of lucerne (Medicago sativa L.) in pastoral agriculture. Crop and Pasture Science, 63, 734–738.

[21] Bouton, J. H. (2012b). Breeding lucerne for persistence. Crop and Pasture Science, 63, 95–106.

[22] Bouton, J. H. (2023). Industry perspectives, challenges, and opportunities in warm climates. In R. Smith & T. Bowling (Eds.), In Proceedings of the XXV International Grassland Congress (pp. 439–442). Curran Associates, Inc.

[23] Bouton, J. H., & Gates, R. N. (2003). Grazing-tolerant alfalfa cultivars perform well under rotational stocking and hay management. Agronomy Journal, 95, 1461–1464.

[24] Bouton, J. H., Gates, R. N., Wood, D. T., & Utley, P. R. (1997). Registration of ‘ABT 805’ alfalfa. Crop Science, 37, 293.

[25] Bouton, J. H., Smith, Jr., R. S. (1998). Standard test to characterize alfalfa cultivar tolerance to intensive grazing with continuous stocking. North American Alfalfa Improvement Conference. Standard Tests. https://www.naaic.org/stdtests/grazing.pdf

[26] Bouton, J. H., Smith, Jr., S. R., Wood, D. T., Hoveland, C. S., & Brummer, E. C. (1991). Registration of ‘Alfagraze’ alfalfa. Crop Science, 31, 479.

[27] Bouton, J. H., Sumner, M. E., Hammel, J. E., & Shahandeh, H. (1986). Yield of an alfalfa germplasm selected for acid soil tolerane when grown in soils with modified subsoils. Crop Ecology, Production & Management, 26, 334–336.

[28] Bowley, S. R., & Christie, B. R. (1981). Inheritance of dry matter yield in a heterozygous population of alfalfa. Canadian Journal of Plant Science, 61, 313–318.

[29] Brown, R. H., & Byrd, G. T. (1990). Yield and botanical composition of alfalfa-bermudagrass mixtures. Agronomy Journal, 82, 1074–1079.

[30] Brown, R. H., Pearce, R. B., Wolf, D. D., & Blaser, R. E. (1972). Energy Accumulation and Utilization. In C. H. Hanson (Ed.), Alfalfa science and technology. Agronomy No. 15 (p. 148). Agronomy Monographs.

[31] Brummer, C. E., & Casler, M. D. (2014). Cool-season forages. In S. Smith, B. Diers, J. Specht, & B. Carver (Eds.), Yield gains in major US field crops (Vol. 33, pp. 33–51). CSSA Special Publications.

[32] Brummer, E. C., Bouton, J. H., & Kochert, G. (1993). Development of an RFLP map in diploid alfalfa. Theoretical and Applied Genetics, 86–86, 329–332.

[33] Burt, J. C., Baxter, L. L., Prevatt, C. G., Kimberly Mullenix, M., Stewart, Jr., R. L., & Tucker, J. J. (2023). Improving bermudagrass in the southeastern United States with alfalfa as an alternative nitrogen source in grazing systems. Grassland Research, 1, 280–289.

[34] Burt, J. C., Baxter, L. L., Silva, L. S., Vasco, C., Mullenix, M. K., Prevatt, C. G., Stewart, L. S., & Tucker, J. J. (2024). Alfalfa-bermudagrass mixtures managed under contrasting harvest strategies in the southeastern US. I. Agronomy and animal responses. Grass and Forage Science.

[35] Burton, G. W. (1976). Legume nitrogen versus fertilizer nitrogen for warm-season grasses. In C. S. Hoveland, W. E. Knight, & G. C. Marten (Eds.), Biological N fixation in forage-livestock systems. ASA Special Publication Number 28. American Society of America.

[36] Casler, M. D., & Brummer, E. C. (2008). Theoretical expected genetic gains for among-and-within-family selection methods in perennial forage crops. Crop Science, 48, 890–902.

[37] Cassida, K. A., Stewart, C. B., Haby, V. A., & Gunter, S. A. (2006). Alfalfa as an alternative to bermudagrass for pastured stocker cattle systems in the Southern USA. Agronomy Journal, 98, 705–713.

[38] Castonguay, Y., Laberge, S., Brummer, E. C., & Volenec, J. J. (2006). Alfalfa winter hardiness: A research retrospective and integrated perspective. Advances in Agronomy, 90, 203–265.

[39] Cazenave, A. B., Shah, K., Trammell, T., Komp, M., Hoffman, J., Motes, C. M., & Monteros, M. J. (2019). High-throughput approaches for phenotyping alfalfa germplasm under abiotic stress in the field. The Plant Phenome Journal, 2, 1–13.

[40] Feng, Y., Shi, Y., Zhao, M., Shen, H., Xu, L., Luo, Y., Liu, Y., Xing, A., Kang, J., Jing, H., & Fang, J. (2022). Yield and quality properties of alfalfa (Medicago sativa L.) and their influencing factors in China. European Journal of Agronomy, 141, 126637.

[41] Fernandes Filho, C. C., Andrade, M. H. M. L., Nunes, J. A. R., Jarquin, D. H., & Rios, E. F. (2023). Genomic prediction for complex traits across multiples harvests in alfalfa (Medicago sativa L.) is enhanced by enviromics. The Plant Genome, 16, e20306.

[42] Fisher, M. (2017). Reduced-lignin alfalfa provides flexibility for farmers. Crops & Soils, 50, 4–9.

[43] Forage Genetics, LLC. (n.d.). Got Bermudagrass initiative. https://www.americasalfalfa.com/Alfalfa-Varieties/Got-Bermudagrass.aspx

[44] Goplen, B. P., Howarth, R. E., & Lees, G. L. (1993). Selection of alfalfa for a lower initial rate of digestion and corresponding changes in epidermal and mesophyll cell wall thickness. Canadian Journal of Plant Science, 73, 111–122.

[45] Grigson, D. (n.d.) Impact of alfalfa in Lincoln County. University of Kentucky Cooperative Extension System. https://uknowledge.uky.edu/cgi/viewcontent.cgi?article=1102&context=ky_alfalfa

[46] Haby, V. A. (2002). Soil fertility and management of acid Coastal Plain soils for crop production. Communications in Soil Science and Plant Analysis, 33, 2497–2520.

[47] Hancock, K., Collette, V., Chapman, E., Hanson, K., Temple, S., Moraga, R., & Caradus, J. (2014). Progress towards developing bloat-safe legumes for the farming industry. Crop and Pasture Science, 65, 1107–1113.

[48] Hanna, W. W., & Sollenberger, L. E. (2015). Tropical and subtropical grasses. In R. F. Barnes, C. J. Nelson, K. J. Moore, & M. Collins (Eds.), Forages volume II: The science of Grassland agriculture (16, 6th ed., pp. 245–255). Blackwell Publishing.

[49] Hawkins, C., & Yu, L. X. (2018). Recent progress in alfalfa (Medicago sativa L.) genomics and genomic selection. The Crop Journal, 6, 565–575.

[50] Hendricks, T. J., Tucker, J. J., Hancock, D. W., Mullenix, M. K., Baxter, L. L., Stewart, Jr., R. L., Segers, J. R., & Bernard, J. K. (2020). Forage accumulation and nutritive value of bermudagrass and alfalfa-bermudagrass mixtures when harvested for baleage. Crop Science, 60, 2792–2801.

[51] Hersom, M., Driver, D., Faircloth, B., & Wasdin, J. (2007). Utilization of round bale silage as a complement to hay production. University of Florida Beef Report, 56, 25–28.

[52] Hoppen, S. M., Neres, M. A., Ta, H., Yang, X., Mills, A., Jáuregui, J., & Moot, D. J. (2022). Canopy dynamics of lucerne (Medicago sativa L.) genotypes of three fall dormancies grown under contrasting defoliation frequencies. European Journal of Agronomy, 140, 126601.

[53] Horner, E. S. (1970). Registration of Florida 66 Alfalfa1 (Reg. No. 48). Crop Science, 10, 456.

[54] Horner, E. S., & Ruelke, O. C. (1981). Registration of Florida 77 Alfalfa 1 (Reg. No. 99). Crop Science, 21, 797.

[55] Hoveland, C. S. (1989). Legume persistence under grazing in stressful environments. In C. G. Marten, A. G. Matches, R. F. Barnes, R. W. Brougham, R. J. Clements, & G. W. Sheath (Eds.), Persistence of forage legumes (pp. 375–385). ASA, CSSA, and CSSA Books.

[56] Hoveland, C. S. (1992). Grazing systems for humid regions. Journal of Production Agriculture, 5, 23–27.

[57] Hoveland, C. S., Hill, N. S., Lowrey, Jr., R. S., Fales, S. L., McCormick, M. E., & Smith, Jr., A. E. (1988). Steer performance on birdsfoot trefoil and alfalfa pasture in Central Georgia. Journal of Production Agriculture, 1, 343–346.

[58] Jia, C., Zhao, F., Wang, X., Han, J., Zhao, H., Liu, G., & Wang, Z. (2018). Genomic prediction for 25 agronomic and quality traits in alfalfa (Medicago sativa). Frontiers in Plant Science, 9, 1220.

[59] Van Keuren, R. W., & Marten, G. C. (1972). Pasture production and utilization. In C. H. Hanson (Ed.), Alfalfa science and technology (pp. 641–658). Agronomy Monographs.

[60] Killerby, M. A., Reyes, D. C., White, R., & Romero, J. J. (2022). Meta-analysis of the effects of chemical and microbial preservatives on hay spoilage during storage. Journal of Animal Science, 100(3), 1–13.

[61] Klotz, J. L., & Bouton, J. H. (2021). Joint International Grassland and International Rangeland Congress Kenya 2021: Grasslands Summary. In Kenya Agricultural and Livestock Research Organization, Nairobi, Kenya (Ed.), Proceedings of Joint International Grassland and International Rangeland Congress–Plenary, Keynote, & Summary Papers. https://uknowledge.uky.edu/cgi/viewcontent.cgi?article=4923&context=igc

[62] Lacefield, G., Ball, D., Hancock, D., Andrae, J., & Smith, R. (2019). Growing alfalfa in the South. National Alfalfa and Forage Alliance. https://www.alfalfa.org/pdf/alfalfainthesouth.pdf

[63] Lamb, J. F. S., Sheaffer, C. C., Rhodes, L. H., Sulc, R. M., Undersander, D. J., & Brummer, E. C. (2006). Five decades of alfalfa cultivar improvement: Impact on forage yield, persistence, and nutritive value. Crop Science, 46, 902–909.

[64] Lark, T. J. (2020). Protecting our prairies: Research and policy actions for conserving America’s grasslands. Land Use Policy, 97, 104727.

[65] Leach, G. J., & Clements, R. J. (1984). Ecology and grazing management of alfalfa pastures in the subtropics. In N. C. Brady (Ed.), Advances in agronomy (Vol. 37, pp. 127–154). Academic Press, Inc.

[66] Li, X., & Brummer, E. C. (2012). Applied genetics and genomics in alfalfa breeding. Agronomy, 2(1), 40–61.

[67] Li, X., Han, Y., Wei, Y., Acharya, A., Farmer, A. D., Ho, J., Monteros, M. J., & Brummer, E. C. (2014). Development of an alfalfa SNP array and its use to evaluate patterns of population structure and linkage disequilibrium. PLoS One, 9(1), e84329.

[68] Li, X., Wei, Y., Acharya, A., Jiang, Q., Kang, J., & Brummer, E. C. (2014). A saturated genetic linkage map of autotetraploid alfalfa (Medicago sativa L.) developed using genotyping-by-sequencing is highly syntenous with the Medicago truncatula genome. G3: Genes, Genomes, Genetics, 4, 1971–1979.

[69] Lu, X., Ji, S., Hou, C., Qu, H., Li, P., & Shen, Y. (2018). Impact of root C and N reserves on shoot regrowth of defoliated alfalfa cultivars differing in fall dormancy. Grassland Science, 64, 83–90.

[70] McCaslin, M. (1994). Insights into the mechanisms of resistance to the potato leafhopper by glandular-haired alfalfa. In F. W. Shockley & E. A. Backus (Eds.), In Proceedings of the 1998 North American Alfalfa Improvement Conference. University of Missouri. https://www.naaic.org/Publications/1998Proc/1998Reports.pdf#page=78

[71] McCaslin, M. (2005). History of Roundup Ready^® alfalfa. Kentucky Alfalfa and Stored Forage Conference. https://uknowledge.uky.edu/cgi/viewcontent.cgi?article=1108&context=ky_alfalfa

[72] McKenzie, J. S., Roger, P., & Duke, S. H. (1988). Cold and heat tolerance. In A. A. Hanson, D. K. Barnes, & R. R. Hill (Eds.), Alfalfa and alfalfa improvement. Agronomy No. 29 (p. 285). ASA, CSA, SSSA Books.

[73] Moore, K. J., Boote, K. J., & Sanderson, M. A. (2004). Physiology and developmental morphology. In L. E. Moser, B. L. Burson, & L. E. Sollenberger (Eds.), Warm-season (C₄) grasses. Agronomy No 45 (pp. 187–188). ASA, CSA, SSSA Books.

[74] Moore, K. J., Collins, M., Nelson, J. C., & Redfearn, D. D. (2020). Forages, volume 2: The science of grassland agriculture (7th ed., p. 976). Wiley-Blackwell Publishing.

[75] Mott, G. O. (1960). Grazing pressure and the measurement of pasture production. In C. L. Sidmore (Ed.), In Proceedings of the 8th International Grassland Congress (pp. 606–611). Alden Press.

[76] Muir, J. P., Pitman, W. D., Dubeux, Jr., J. C., & Foster, J. L. (2014). The future of warm-season, tropical and subtropical forage legumes in sustainable pastures and rangelands. African Journal of Range & Forage Science, 31, 187–198.

[77] Mullenix, M. K., Silva, L. S., Prevatt, C. G., & Tucker, J. J. (2023). Farmer experiences with alfalfa in the southern USA. In R. Smith & T. Bowling (Eds.), In Proceedings of the XXV International Grassland Congress (pp. 752–755). Curran Associates, Inc.

[78] National Alfalfa Forage Alliance (NAFA). (2023). https://www.alfalfa.org/

[79] Pedreira, C. G. S., Silva, V. J., Ferragine, M. D. C., Bouton, J. H., Tonato, F., Otani, L., & Basto, D. C. (2020). Validating the NAAIC alfalfa grazing tolerance standard test and assessing physiological responses to grazing in a tropical environment. Crop Science, 60, 1702–1710.

[80] Pruitt, J. R., & Lacy, R. C. (2013). Economics of baleage for beef cattle operations (p. 9). Lousiana State University AgCenter Publication 3330.

[81] Quesenberry, K. H., Rios, E. F., Kenworthy, K. E., Blount, A. R., & Reith, P. E. (2022). Breeding forages with climate resiliency in temperate/tropical transition zones. Grass and Forage Science, 77, 124–130.

[82] Riday, H., & Brummer, E. C. (2004). Performance of intersubspecific alfalfa hybrids in sward versus space planted plots. Euphytica, 138, 107–112.

[83] Rimi, F., Macolino, S., Leinauer, B., Lauriault, L. M., & Ziliotto, U. (2014). Fall dormancy and harvest stage impact on alfalfa persistence in a subtropical climate. Agronomy Journal, 106, 1258–1266.

[84] Rios, E. F., Murad Andrade, M., Fernandes Filho, C. C., Sipowicz, P., Biswas, A., Ulbricht, R., Basigalup, D., & Brummer, E. C. (2023). Plant breeding perspectives for alfalfa (Medicago sativa L.) success in warm climates. In R. Smith & T. Bowling (Eds.), In Proceedings of the XXV International Grassland Congress (pp. 838–841). Curran Associates, Inc.

[85] Robins, J. G., Hansen, J. L., Viands, D. R., & Brummer, E. C. (2008). Genetic mapping of persistence in tetraploid alfalfa. Crop Science, 48, 1780–1786.

[86] Romero, N. A., Comeron, E. A., & Ustarroz, U. (1995). Capítulo 8. Crecimiento y utilización de la alfalfa. In E. H. Hijano & A. Navarro (Eds.), La alfalfa en la Argentina. INTA Subprograma Alfalfa. Enciclopedia Agro de Cuyo, Manuales (Vol. 11, pp. 149–170). INTA.

[87] Rushing, B., Lemus, R., Maples, J. G., & Lyles, J. C. (2022). Stocker cattle performance on interseeded alfalfa bermudagrass pastures in Mississippi. Crop, Forage & Turfgrass Management, 8(1), e20164.

[88] Russelle, M. P. (2013). The Alfalfa Yield Gap: A review of the evidence. Forage & Grazinglands, 11(1), 1–8.

[89] Sakiroglu, M., & Brummer, E. C. (2017). Identification of loci controlling forage yield and nutritive value in diploid alfalfa using GBS-GWAS. Theoretical and Applied Genetics, 130, 261–268.

[90] Samac, D. A., Brummer, E. C., McKersie, B., & Skinner, D. Z. (1998). Report of the committee of the use of biotechnology research in alfalfa improvement. In Proceedings of the 36th North American Alfalfa Improvement Conference. Montana State University. http://www.naaic.org

[91] dos Santos, I. G., Cruz, C. D., Nascimento, M., Rosado, R. D. S., & de Ferreira, R. P. (2018). Direct, indirect, and simultaneous selection as strategies for alfalfa breeding on forage yield and nutritive value. Pesquisa Agropecuária Tropical, 48, 178–189.

[92] Sheaffer, C. C., & Marten, G. C. (1990). Alfalfa cutting frequency and date of fall cutting. Journal of Production Agriculture, 3, 486–491.

[93] Shelton, H. M., Franzel, S., & Peters, M. (2005). Adoption of tropical legume technology around the world: Analysis of success. In D. A. McGilloway (Ed.), Proceedings of the XX International Grassland Congress (pp. 149–166). Wageningen Academic Publishers. https://hdl.handle.net/10568/55508

[94] Silva, L., Mullenix, K., Dillard, L., Kesheimer, K., & Russell, D. (2020). Alfalfa establishment and management. Alabama Cooperative Extension System Publication ANR, 2687, 6. https://www.aces.edu/blog/topics/farming/alfalfa-establishment-and-management/

[95] Silva, L. S., Mullenix, M. K., Prevatt, C., & Tucker, J. J. (2021). Perceptions of adoption of alfalfa plantings by forage-livestock producers in the Southern United States. Applied Animal Science, 37, 665–669.

[96] Smith, Jr., S. R., & Bouton, J. H. (1993). Selection within Alfalfa cultivars for persistence under continous stocking. Crop Science, 33, 1321–1328.

[97] Smith, Jr., S. R., Bouton, J. H., & Hoveland, C. S. (1989). Alfalfa persistence and regrowth potential under continuous grazing. Agronomy Journal, 81, 960–965.

[98] Smith, S. R., Lea, K., Henning, J., Basigalup, D., & Putnam, D. H. (2021). Grazing alfalfa: Economic and sustainable use of a high-value crop. National Alfalfa and Forage Alliance. https://www.alfalfa.org/pdf/GrazingAlfalfaFinal.pdf

[99] Sollenberger, L. E., & Dubeux, Jr., J. C. (2022). Warm-climate, legume-grass forage mixtures versus grass-only swards: An ecosystem services comparison. Revista Brasileira de Zootecnia, 51, e20210198.

[100] Stringer, W. C., Khalilian, A., Undersander, D. J., Stapleton, G. S., & Bridges, Jr., W. C. (1994). Row spacing and nitrogen: Effect on Alfalfa-Bermudagrass yield and botanical composition. Agronomy Journal, 86, 72–76.

[101] Stringer, W. C., Morton, B. C., & Pinkerton, B. W. (1996). Row spacing and nitrogen: Effect on alfalfa-bermudagrass quality components. Agronomy Journal, 88, 573–577.

[102] Tang, Z., Parajuli, A., Chen, C. J., Hu, Y., Revolinski, S., Medina, C. A., Lin, S., Zhang, Z., & Yu, L. X. (2021). Validation of UAV-based alfalfa biomass predictability using photogrammetry with fully automatic plot segmentation. Scientific Reports, 11, 3336.

[103] Tarnonsky, F., Hochmuth, K., DiCostanzo, A., & DiLorenzo, N. (2023). Effects of replacing corn silage with alfalfa haylage in growing beef cattle diets on performance during the growing and finishing period. Journal of Animal Science, 101, skac397.

[104] Teuber, L. R., Taggard, K. L., Gibbs, L. K., McCaslin, M. H., Peterson, M. A., & Barnes, D. K. (1998). Fall dormancy—Standard tests to characterize alfalfa cultivars. NAAIC. https://www.naaic.org/stdtests/dormacy2.pdf

[105] Tucker, J. J., Hendricks, T. J., Mason, K. B., Mullenix, M. K., Prevatt, C. G., & Hancock, D. W. (2019). Alfalfa in the south workshop series: Increasing acreage through education. Journal of the National Association of County Agricultural Agents, 12, 1–4.

[106] Tucker, J. J., Mullenix, M. K., & Prevatt, C. G. (2023). Alfalfa production and adaptability as monoculture and mixed grass systems. In R. Smith & T. Bowling (Eds.), In Proceedings of the XXV International Grassland Congress (pp. 951–953). Curran Associates, Inc.

[107] Tucker, J. J., Mullenix, M. K., Silva, L. S., Prevatt, C. G., Samac, D., Kesheimer, K., & Tomaso-Peterson, M. (2021). Alfalfa bermudagrass management guide. National Alfalfa and Forage Alliance. https://www.alfalfa.org/pdf/AlfalfaBermudagrass-LowRes.pdf

[108] United States Department of Agriculture National Agricultural Statistics Service. (2023). Production Acreage Maps. www.nass.usda.gov

[109] Ustarroz, E., Kloster, A., Latimori, N., Zaniboni, M., & Mendez, D. (1997). Intensification of wintering on alfalfa-based pastures. In Proceedings of the First National Congress on Intensive Meat Production (pp. 181–204). INTA-Forrajes y Granos-SAGPyA.

[110] Velez-Santiago, J., Arroyo-Aguilu, J. A., Fuentes, F., & Torres, A. (1984). Evaluation of eight alfalfa cultivars in a cumulic haplustolls of Southern Puerto Rico. Journal of Agriculture of the University of Puerto Rico, 68(2), 121–130.

[111] Ventroni, L. M., Volenec, J. J., & Cangiano, C. A. (2010). Fall dormancy and cutting frequency impact on alfalfa yield and yield components. Field Crops Research, 119, 252–259.

[112] Vilela, D., Basigalup, D. H., Juntolli, F. V., & Ferreira, R. P. (2018). Research priorities and future of alfalfa in Latin America. In Proceedings of the Second World Alfalfa Congress (pp. 140–143), INTA. https://repositorio.inta.gob.ar/handle/20.500.12123/4031

[113] White, J. A., Lemus, R., & Varco, J. J. (2021). The recovery of ¹⁵N in the aerial biomass of alfalfa-bahiagrass mixtures. Crop Forage & Turfgrass Management, 7(1), e20104.

[114] Wolf, D. D., & Allen, V. G. (1990). Yield and regrowth characteristics of alfalfa grazed by steers during spring and summer. Agronomy Journal, 82, 1079–1082.

[115] Woodfield, D. R., Roldan, M. B., Voisey, C. R., Cousins, G. R., & Caradus, J. R. (2019). Improving environmental benefits of white clover through condensed tannin expression. Journal of New Zealand Grasslands, 81, 195–202.

[116] Zhao, D., Mejia-Guerra, K. M., Mollinari, M., Samac, D., Irish, B., Heller-Uszynska, K., Beil, C. T., & Sheehan, M. J. (2023). A public mid-density genotyping platform for alfalfa (Medicago sativa L.). Genetic Resources, 4, 55–63.

RIGHTS & PERMISSIONS

2024 The Authors. Grassland Research published by John Wiley & Sons Australia, Ltd on behalf of Chinese Grassland Society and Lanzhou University.