Little is known about the relative performance of weeping lovegrass in mixtures with alfalfa. Our objective was to compare the productivity and forage quality of monocultures and binary mixtures of the species. Mixtures always gave higher yields than any of the monocultures and the highest was obtained in the mixture with the largest proportion of alfalfa. In the second year weeping lovegrass N concentration in the mixtures were higher than in monoculture. Weeping lovegrass did not affect the alfalfa N concentration. There was not differences in the NDF, for between these species

Brevedan, R. E.

Fioretti, M. N.

Laborde, H.

Varillas, M. A.

English

University of Kentucky

University of Kentucky UKnowledge International Grassland Congress Proceedings XIX International Grassland Congress Yield and Forage Quality in Alfalfa-Weeping Lovegrass Mixtures H. Laborde Universidad Nacional del Sur, Argentina R. E. Brevedan Universidad Nacional del Sur, Argentina M. A. Varillas Universidad Nacional del Sur, Argentina M. N. Fioretti Universidad Nacional del Sur, Argentina Follow this and additional works at: https://uknowledge.uky.edu/igc  Part of the Plant Sciences Commons, and the Soil Science Commons This document is available at https://uknowledge.uky.edu/igc/19/2/11 This collection is currently under construction. The XIX International Grassland Congress took place in São Pedro, São Paulo, Brazil from February 11 through February 21, 2001. Proceedings published by Fundacao de Estudos Agrarios Luiz de Queiroz This Event is brought to you for free and open access by the Plant and Soil Sciences at UKnowledge. It has been accepted for inclusion in International Grassland Congress Proceedings by an authorized administrator of UKnowledge. For more information, please contact UKnowledge@lsv.uky.edu. ID # 02-14YIELD AND FORAGE QUALITY IN ALFALFA-WEEPING LOVEGRASSMIXTURESH.E. Laborde, R.E. Brevedan, M.A. Varillas and M.N. Fioretti.Departamento de Agronomía and CERZOS, Universidad Nacional del Sur-CONICET, 8000Bahía Blanca, Argentina.AbstractLittle is known about the relative performance of weeping lovegrass in mixtures withalfalfa. Our objective was to compare the productivity and forage quality of monocultures andbinary mixtures of the species. Mixtures always gave higher yields than any of themonocultures and the highest was obtained in the mixture with the largest proportion ofalfalfa. In the second year weeping lovegrass N concentration in the mixtures were higherthan in monoculture. Weeping lovegrass did not affect the alfalfa N concentration. There wasnot differences in the NDF, for between these species.Keywords: Intercropping, land equivalent ratio, semi-arid regionIntroductionHigh yielding legume-grass mixtures are an important part in forage-animalproduction. Legume grass forage mixtures offer several potential advantages over puregrasses or pure legume, such as transfer of symbiotically fixed nitrogen to grasses (Ledgard,1991), extended stand longevity and weed control (Drolson and Smith, 1976). But it isdifficult to keep the components in the mixture and specially to maintain each component at aspecified level (Smith et al., 1986) due to a high degree of competition between itscomponents. They compete for light, water and mineral nutrients (Jones et al., 1988). Theproduction of better quality forage (Jung et al., 1991) and reduced nitrogen inputs(Whitehead, 1995) makes legume-grass mixtures very attractive.Alfalfa (M. sativa) is well adapted throughout Argentina. The area in production isover 5.0 million ha, including pure stands and alfalfa-grass mixtures. Weeping lovegrass isthe most important forage crop in the semi-arid region of Argentina. It is sown over 700,000ha.Our objectives were to evaluate yield potential and nutritional value of a mixed swardof alfalfa-weeping lovegrass during a 2-year period.Material and MethodsThe experiment was conducted at the Agronomy Department of the UniversidadNacional del Sur, Bahía Blanca (38º 45´S, 62º 11´W), Argentina.Treatments were,two monocultures:1) Weeping lovegrass (W)2) Alfalfa (A)and three mixtures:3) Alternate single rows, one row of weeping lovegrass, one row of alfalfa (W/A)4) Alternate double row of alfalfa, one row of weeping lovegrass (W/2A)5) Interseeded, weeping lovegrass and alfalfa together in the same row at a plant densityproportion of 1:1 (WA).There were 6 replications per treatment. Each plot was 2.4 by 6 m.Weeping lovegrass (Eragrostis curvula (Schrad.) Nees) cv. Ermelo and alfalfa(Medicago sativa L) cv. Armona, were seeded in October 1993 in a deep sandy soil. Plotswere hand weeded during the experiment.Dry matter yield was obtained by clipping, at a stubble height of 7 cm in all cases.Percentage composition of alfalfa-weeping lovegrass mixtures on a dry weight basis wasobtained after hand separation of the species at each harvest. Plant material was dried toconstant weight at 60ºC. Neutral detergent fiber (NDF) was determined (Goering and VanSoest, 1970) and total nitrogen (N) by semimicroKjeldahl procedure.The land equivalent ratio (LER) was calculated following Willey (1979).Data were analysed by analysis of variance using a randomized complete block designwith Duncan´s multiple range test to determine differences among treatment means.Results and DiscussionMixtures of alfalfa and weeping lovegrass had higher dry matter yields thanmonocultures (Table 1). These results agree with the ones reported by Ta and Faris (1987),Adúriz and Gargano (1989) and Gökkus et al. (1999). In the second year there was a decreasein dry matter yields for all treatments, but again the mixtures gave the highest  yields (Table1). There were no significant differences among the mixtures, but the one with greatestproportion of alfalfa (W/2A) gave the highest yield (Table 1).In the second year LER values of the mixtures were higher than 1.2 (Table 1). A LERvalue higher than 1.0 indicates that monocultures used more land than the intercrop to provideequal quantitites of the products and the magnitude of LER shows the increase in biologicalefficiency of the intercropping. The results indicated the advantage of the mixtures comparedto weeping lovegrass alone or alfalfa alone. Similar results were observed by Ta and Faris(1987).In the second year there was a significant increase in the weeping lovegrass Nconcentration grown in mixtures, up to 21%, over weeping lovegrass alone (Table 2). Similarresults were observed by Haystead and Marriott (1979) and Ta and Faris (1987). This resultcan be due to a decomposition of alfalfa tissues (Butler et al., 1959) or to a root excretion ofN (Ta et al., 1986). In the first year, N concentration of weeping lovegrass was also higher inthe mixtures but the differences were not significant. An increase in the alfalfa proportion ofthe mixtures resulted in an increased concentration of weeping lovegrass nitrogen. Alfalfanitrogen concentration was not affected by the presence of weeping lovegrass.Neutral detergent fiber of alfalfa and weeping lovegrass did not change by thepresence of the other species in both years (Table 2).The results showed the advantages of mixing weeping lovegrass and alfalfa overweeping lovegrass alone or alfalfa alone for herbage production and quality.AcknowledgmentThe proyect received financial assistance from ANPCYT-Argentina (Project 08-4516).The contribution is gratefully acknowledged.ReferencesAdúriz, M.A. and Gargano A.O. (1989). Effects of frequencies and intensities of defoliationon alfalfa (Medicago sativa) and weeping lovegrass (Eragrostis curvula), mixture, 1- Drymatter yields. Revista Argentina de Producción Animal. 9:33-40.Butler, G.W., Greenwood R.W. and Soper K. (1959). Effects of shading and defoliation onthe turnover of root and nodule tissue of plants of Trifolium repens, Trifolium pratense, andLotus uliginosus. New Zealand Journal of Agricultural Research 2:415-426.Drolsom, P.N. and Smith D. (1976). Adapting species for forage mixtures. In: R.I.Papendick, P.A. Sanchez and G.B. Triplett (ed). Multiple cropping. ASA. Madison, Wis. pp.223-232.Goering, H.K. and Van Soest P.J. (1970). Forage fiber analysis (apparatus, reagents,procedures, and some applications). USDA Handb. 379 U.S. Gov. Print. Office, Washington,DC.Gökkus, A., Koc A., Serin Y., Comakli B., Tan M. and Kantar F. (1999). Hay yield andnitrogen harvest in smooth bromegrass mixtures with alfalfa and red clover in relation tonitrogen application. European Journal of Agronomy 10:145-151.Haystead, A. and Marriott C. (1979). Transfer of legume nitrogen to associated grass. SoilBiology and Biochemistry 11: 99-104.Jones, T.A., Carlson I.T. and Buxton D.R. (1988). Reed canarygrass binary mixtures withalfalfa and birdsfoot trefoil in comparison to monocultures. Agronomy Journal 80:49-55.Jung, G.A., Shaffer J.A. and Posenberg J.L. (1991). Sward dynamics and herbagenutritional value of alfalfa-ryegrasss mixtures. Agronomy Journal 83:786-794.Ledgard, S.F.  (1991). Transfers of fixed nitrogen from white clover to associated grasses inswards grazed by dairy cows, estimated using 15N methods. Plant and Soil 131: 215-223.Smith, D., Bula, R.J. and Walgenbach, R.P. (1986). Forage management. Kendall/Hunt,Dubuque, Ia.Ta, T.C. and Faris M.A. (1987). Effects of alfalfa proportions and clipping frequencies ontimothy-alfalfa mixtures. II. Nitrogen fixation and transfer. Agronomy Journal 79:820-824.Ta, T.C., Macdowall F.D.H. and Faris M.A. (1986). Excretion of nitrogen assimilated fromN2 fixed by nodulated roots of alfalfa (Medicago sativa L.). Canadian Journal of Botany64:2063-2067.Whitehead, D.C. (1995). Grassland nitrogen. CAB International, Wallingford, UK, pp. 387.Willey, R.W. (1979). Intercropping - its importance and research needs. Part 1. Competitionand yield advantages. Field Crop Abstracts 32:1-10.Table 1  - Dry matter (DM) yield of weeping lovegrass (W) and alfalfa (A) in pure stands (Wor A, alone) and mixtures (W/A or W/2A or WA interseeded) and the percentage of the alfalfain each stand in 1994 and 1995. Land equivalent ratio (LER) of weeping lovegrass and alfalfamixtures (W/A or W/2A or WA interseeded) in 1995.1994 1995DM A proportion DM A proportion LERTreatment t ha-1 (%) t ha-1 (%)A alone 6.53* b 100 3.29 b 100 -W/A 7.51 a 47 4.73 a 38 1.22 aW/2A 8.35 a 68 4.61 a 51 1.35 aWA interseeded 7.92 a 48 3.81 ab 35 1.30 aW alone 5.68 c 0 3.26 b 0 -*values within any column followed by the same letter are not significantly different at the0.05 level using Duncan´s multiple range test.Table 2  - Average total nitrogen (N) and neutral detergent fiber (NDF) concentration ofweeping lovegrass (W) and alfalfa (A) on pure stands (W or A alone) and mixtures (W/A orW/2A or WA interseeded in 1994) and 1995.1994 1995N NDF N NDFTreatment W A W A W A W A______________________________ % ______________________________A alone - 3.59 a - 39.5 a - 3.51 a - 40.1 aW/A 1.07*a 3.44 a 78.3 a 40.1 a 1.13 a 3.44 a 79.5 a 39.8 aW/2A 1.10 a 3.50 a 76.5 a 36.6 a 1.19 a 3.47 a 80.0 a 37.6 aWA interseeded 1.10 a 3.51 a 78.0 a 37.9 a 1.12 a 3.44 a 79.3 a 39.2 aW alone 1.01 a - 78.3 a - 0.98 b - 81.0 a -*values within any column followed by the same letter are not significantly different at the0.05 level using Duncan´s multiple range test.

Yield and Forage Quality in Alfalfa-Weeping Lovegrass Mixtures

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Yield and Forage Quality in Alfalfa-Weeping Lovegrass Mixtures

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