Development of compatible, persistent, wann-season f:rass-legume mixtuns could increase forage yield and quality during summer months. We established a trial to detennine forage yield, quality, species compatibility, and persistence of binary mixtures of wann·st·ason grasses with selected legumes, five of which are native to the ~:entral USA. Grass entries were switchgrass (Panicum virgaJum L.), sideoats grama (Bouleloua curtipendula Michx.), and indiangrass [Sorghastrum nutans (L.) Nash]. Legume entries were purple prairieclover [Dalea purpurea Vent.; syn. Petalostemon purpureum (Vent.) Rydb.], roundhead lespedeza (Lespedeza capitata Michx.), leadplant fAmorplra canescens Pursh), Ulinois bundleOower [Desmanthus illinoensis (Mich{.) MacMill., B. Robins. & Fern.), catclaw sensitive brier [Schrankia nuttaUii (DC.) Standi.), and cicer milkvetch (Astragalus cicer L.), a cool-season species. Unfertilized grass plots without legumes also were included. The experiment was on a Haynie very fine sandy loam soil (coarse-silty, mixed, calcareous, mesic Typic Udifluvents). All mixtures containing purple prairieclover, roundhead lespedeza, Illinois bunolleflower, or catclaw sensitive brier yielded more forage than did g1·asses grown alone or with leadplant, except for pure switchgrass in 1986. All legumes increased the crude protein concentration of fora:~e compared to that of grass-alone plots, except for leadplant with switchgrass in 1986. Inclusion of catclaw sensitive brier and cicer milkvetch with grasses consistently improved in vitro digestible dry mutter concentration (IVDDM), while inclusion of roundhead lespedeza, leadplant, and Illinois bundleflower generally resulted in decreased IVDDM concentration of forage. Purple prairieclover generally did :mot influence JVDMD of mixtures. Persistence of all legumes was good. Cicer milkvetch was not compatible with these grasses because it developed a thick, dense canopy prior to initiation of growth by these grasses.T HE ADVANTAGES OF COOL-SEASON LEGUMES in coolseason pasture and hayland plantings :have been well documented (Burns and Standaert, 1985;Wagner, 1954). Including adapted legumes with grasses in a mixture has consistently increased forage yield and quality compared to unfertilized grasses. Rumbaugh et al. (1982) reported that interplanting alfalfa (Medicago sativa L.) or cicer milkvetch into a stand of crested wheatgrass [Agropyron desertorum (Fisch.) Schult.] significantly increased forage yield, as well as protein concentration and yield of the grass. Broadcast-seeding of biennial sweetclover [Melilotus officina/is (L.) Desr.] into native range increased yield and protein concentration of western wheatgrass [Pascopyron smithii (Rydb.) A. LOve] (Nichols and Johnson, 1969).Cool-season legumes may not be satisfactory companion species in warm-season grass pastun!s. Differences in seedling vigor, optimum time of establishment,

Clarification of relationships among species in mixed stands is essential to enlightened management of forage mixtures. During 1976–1979, we evaluated several grass‐legume mixtures in a field study in eastern Kansas. Grasses were: commercial smooth brome, Bromus inermis Leyss.; ‘Regar’ Turkish brome, B. biebersteinii Roem. &Schult.; ‘Kentucky 31’ tall fescue, Festuca arundinacea Scbreb.; and ‘Ioreed’ reed canarygrass, Phalaris arundinacea L. Legumes were: ‘Kanza’ alfalfa, Medicago sativa L.; ‘Kenstar’ red clover, Trifolium pratense L.; ‘Dawn’ birdsfoot trefoil, Lotus corniculatus L.; and ‘Emerald’ crownvetch, Coronilla varia L. Each grass was grown in a two‐species mixture with each legume, and in a pure stand with 0 and 90 kg N ha‐1 as NH4NO3. Mixtures were obtained by alternating all‐grass and all‐legume drill rows. Legumes were grown in pure stands in an adjacent planting. Both plantings were on a Woodson silt loam of the fine, mixed, thermic family in the Abruptic Argiaquolls subgroup of the Mollisols. Dry matter (DM) yields were obtained from all plots. Proportion of grass in mixtures was determined from hand‐harvested samples. Dry matter yield of the grass component of each mixture was computed as the product of the DM yield of the whole stand and the proportion of grass in the mixture. Crude protein (CP) contents of whole stands and grass components of mixtures were computed as 6.25 times N. Although comparisons varied across years, mixtures averaged as much grass DM (3.21 Mg ha‐1) as unfertilized all‐grass stands (3.07 Mg ha‐1) during the 4‐year period. Crude‐protein contents of grass components of mixtures consistently ranked above those of unfertilized all‐grass stands; differences usually were significant (P < 0.05) but varied in magnitude with year and type of stand. Legumes differed significantly (P < 0.05) every year in DM yield and every year except 1979 in CP content. Over the 4‐year period, however, no legume was clearly superior in either variable.

Little information is available regarding comparative forage quality of alfalfa (Medicago sativa L.) leaves and stems of the nine germplasms from which most North American cultivars have been developed. In a greenhouse trial, forage quality of leaves and stems of the nine germplasms was compared when grown in a common environment and harvested at the same phenological stage. Germplasm sources (and representative cultivar) tested were: Indian (Sirsa #9), African (African), Peruvian (Hairy Peruvian), Flemish (DuPuits), Turkistan (Lahontan), Chilean (Kansas Common), M. varia Martin (Grimm), Ladak (Ladak), M. falcata L. (Anik). Leaves of germplasm sources differed for concentrations of neutral detergent fiber, cellulose, crude protein, true in vitro digestible dry matter, and p‐hydroxybenzaldehyde, vanillic, p‐coumaric, ferulic, and sinapic acids. Stems of germplasm sources differed for concentrations of NDF, hemicellulose, CEL, TIVDDM, and p‐hydroxybenzoic, syringic, p‐coumaric, and ferulic acids. Results indicate that alfalfa germplasm sources differ in nutritive value of leaves and stems.

The influence of tall fescue (Festuca arundinacea Schreb.) on germination and seedling growth of birdsfoot trefoil (Lotus corniculatus L.) was evaluated during 1983‐85 at Manhattan, Kansas. Studies were designed to evaluate tall fescue cv. Kentucky‐31 for possible allelopathic compounds, determine the effects of tall fescue on the germination, seedling growth and yield of birdsfoot trefoil, and to characterize the chemical properties of tall fescue. Fescue produced allelopathic compounds, particularly during the spring and autumn months when it was actively growing. The greatest trefoil inhibition occurred with fescue plant extracts prepared during the autumn (September and October). The concentration of fescue extracts influenced trefoil germination, with greater inhibition as fescue concentration increased. In a sand medium under greenhouse conditions, fescue extracts prepared in spring and autumn reduced trefoil growth by 50 and 56%, respectively, with no inhibition during the summer months. Under field conditions, full strength fescue extracts reduced trefoil plant populations by 14 and 57% with spring and autumn prepared extracts, respectively. Fescue competition reduced sod‐seeded trefoil plants per unit area by 17 and 31% for spring and autumn seeding, respectively. Full strength fescue extracts reduced trefoil seedling growth by an average of 37%, and trefoil dry matter yields by 53%.

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