Relationships between alfalfa (Medicago sativa L.) and associated grasses in a plant community are complex. A concern has developed whether alfalfa was, in fact, benefiting from grass association. A field study was conducted to describe the changes in canopy components of alfalfa‐reed canarygrass (Phalaris arundinacea L.) and alfalfa‐orchardgrass (Dactylis glomerata L.) mixtures. Alfalfa‐grass mixtures of one row of grass between two rows of alfalfa and one row of alfalfa between two rows of grass were planted in a repeating pattern. Monocultures of each species and four binary mixtures were sampled for total, alfalfa and grass component, and stratified alfalfa yields were measured at 10, 20, 30, 40, and 50 d of spring and summer regrowth for 2 yr. Planting pattern, grass species and season of growth affected botanical composition and yield of alfalfa‐grass mixtures. Alfalfa‐grass mixtures yielded more than alfalfa monocultures during only one spring growth cycle. During summer regrowth, alfalfa‐grass mixtures were less productive than alfalfa monocultures. In spring, reed canarygrass accounted for a greater proportion of the total yield than orchardgrass, whereas the two grasses were similar during summer. Grass yields of mixtures were not affected by alfalfa association. The results of this study suggest that alfalfa‐grass mixtures offer little yield advantage over alfalfa monocultures when harvested as hay.

Fall sodseeding of annual forages into perennial warm‐season pastures offers a practical method of extending the grazing season and improving forage quality. A 2‐yr study evaluating the effect of sodseeding method and ryegrass‐clo‐ver mixtures on forage production, animal performance, and economics of sodseeded winter pastures for growing beef animals was conducted. Forage mixtures of either annual ryegrass (Lolium multiflorum Lam.)‐white clover (Trifolium repens L.) (R‐W) or ryegrass‐white clover‐crimson clover (Trifolium incarnatum L.) (R‐W‐C) were sodseeded into common bermudagrass [Cynodon dactylon (L.) Pers.] pastures in the fall by (i) drilling into the sod using a conventional grain drill equipped with a small seed attachment (Drill), or (ii) lightly disking (less than 1 in. deep) before broadcast seeding followed by lightly disking and harrowing (Broadcast). Pastures were grazed with weanling calves beginning in late November in Year 1 and late December in Year 2 through May. Sodseeding method had no effect on total yield. The addition of crimson clover into the mixture increased total forage production (P=0.10), monthly clover percentage (P<0.05) during February, March, and April, and animal grazing days (P<0.05) during April. Animal gains and beef production per acre were not affected by either sodseeding method or mixture averaging 2.15 lb/head/d and 460 lb beef/acre. Economic analysis showed the highest net returns for drilling R‐W mixtures ($93/acre). Bermudagrass hay production following the grazing season was similar for both sodseeding methods and both mixtures. The results of this study suggest that the easiest or least expensive method for fall sodseeding should be considered.

Adequate quantity and quality of cool-season forage are limiting factors in cattle (Bos taurus) producing areas of the subtropics. 'Bigalta' limpograss (Hemarthria altissima (Poir.) Stapf et C.E. Hubb.] has been proposed as a forage with potential to help overcome both problems. A 2-yr study to determine the effect of increasing levels of fall-applied fertilizer on the quality of stockpiled Bigalta limpograss was conducted in central Florida. Eight fertilizer treatments were applied on 10 October each year: (1) 0-0-0, (ii) 34-4-13, (iii) 68-7-26, (iv) 100-11-40, (v) 135-15-54, (vi) 168-18-67, (vii) 200-22-80, and (viii) 400-45-160 kg ha-1 of N-P-K. Forage quality variables were measured in whole plant samples at monthly intervals from 5 December through 5 April, inclusive, and were compared to established National Research Council (NRC) requirements for beef cattle. Yield increases entering into the stockpile period (December) of 285 to 610% (relative to the control) resulted from rates of 68-7-26 kg ha-1 of N-P-K and higher, and these yield increases were maintained through April. Addition of greater than 68-7-26 kg ha-1 of N-P-K consistently increased in vitro dry matter digestibility (IVDMD) crude protein (CP), P, K, and Mn, whereas Zn concentration was decreased by fertilizer application. Acid detergent fiber (ADF), neutral detergent fiber (NDF), and concentrations of Ca, Mg, Fe, and Cu were generally unaffected by fertilizer level. Crude protein, P, and K levels were raised into acceptable NRC ranges, while Zn dropped below the required range as a result of fertilization. Animals grazing stockpiled limpograss of this quality would require supplementation with Zn and Cu during the entire period, while supplementation with CP and P would be required only during February and April, respectively. Both Ca/P and K/(Ca + Mg) ratios were maintained at levels conducive to good beef cattle production throughout the stockpile period.

A 2-year study to compare the effect of liquid and solid N-P-K (9:1:4)fertilizers on 'Callie'bermudagrass (Cynodon dactylon var. aridus Harlan et de Wet) production and nutrient uptake was conducted in Central Florida. There was a positive linear relationship between yield and amount of N-P-K fertilizer applied from both sources. Forage N and K concentrations were positively affected and P levels were unaffected by increased fertility levels. Solid fertilizer increased dry matter production and resulted in higher relative uptake efficiencies of the applied N, P, and K than the liquid source. It also maintained higher N concentrations in the forage in some cuttings than the liquid, but neither P nor K concentrations were affected by the fertilizer source. Ammonia volatilization of the urea in the liquid source was probably the major reason for the lower yield, N concentration, and N uptake efficiency with that source. The trend for lower P and K uptake efficiencies by the liquid-treated forage appears to be associated with the lower yields obtained with this source.

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