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Bermudagrass [Cynodon dactylon (L.) Pers.], a base forage in southeastern United States livestock production, often fails to meet nutrient requirements of some classes of livestock. Contributions of arrowleaf (Trifolium vesiculosum Savi), ball (Trifolium nigrescens Viv.), berseem (Trifolium alexandrinum L.), crimson (Trifolium incarnatum L.), red (Trifolium pratense L.), and white (Trifolium repens L.) clovers to overseeded bermudagrass swards were compared with monoculture bermudagrass receiving 0, 112, or 225 kg ha−1 of N fertilizer on a range of sites. Berseem and crimson clovers produced up to 2.2 Mg ha−1 in March and early April, with berseem particularly reliable on fertile silt loam soils. Red clover was about 3 wk later with growth continuing until July most dependably at the more northern of the loam‐soil locations. Intermediate white clover, although not managed optimally for the species, was a productive late clover only at the southern location. All clovers overseeded on Darley fine sand were unsuccessful both years. Variable responses among clover species and sites from overseeded bermudagrass indicate that this clover production approach is very site specific in the lower southeastern United States.

Sweet sorghum (Sorghum bicolor (L.) Moench) is widely recognized as a highly promising biomass energy crop with particular potential to complement sugarcane production in diversified cropping systems. Agronomic assessments have led to identification of four cultivars well suited for such sugarcane-based production systems in southern Louisiana. Sweet sorghum biofuel production systems are currently being developed, and research producing large sample numbers requiring ethanol yield assessment is anticipated. Fiber analysis approaches developed for forage evaluation appear to be useful for screening such large numbers of samples for relative ethanol yield. Chemical composition, forage fiber characteristics, digestibility, and ethanol production of sweet sorghum bagasse from the four cultivars were assessed. Measures of detergent fiber, lignin, and digestibility were highly correlated with ethanol production (P < 0.01). The best linear regression models accounted for about 80% of the variation among cultivars in ethanol production. Bagasse from the cultivar Dale produced more ethanol per gram of material than any of the other cultivars. This superior ethanol production was apparently associated with less lignin in stems of Dale. Forage evaluation measures including detergent fiber analyses, in vitro digestibility, and an in vitro gas production technique successfully identified the cultivar superior in ethanol yield indicating their usefulness for screening sweet sorghum samples for potential ethanol production in research programs generating large sample numbers from evaluations of germ plasm or agronomic treatments. These screening procedures reduce time and expense of alternatives such as hexose sugar assessment for calculating theoretical ethanol yield.

Sweet sorghum [Sorghum bicolor (L.) Moench] is recognized as a promising biomass energy crop for meeting the increasing demand for bioenergy feedstocks. Field experiments were conducted at sites in northern and southern Louisiana for 2 yr to assess planting date and harvest maturity effects on yield from primary plantings and ratoon crops. The cultivar M81‐E was evaluated using a split plot arrangement of treatments in randomized complete block designs. Planting date from mid‐March to early July was the primary plot treatment. Harvest maturity at the early heading (EH) or hard dough (HD) stage was assigned as the subplot treatment. A range of planting dates from mid‐March to early June produced substantial yields of biomass and fermentable sugar with appropriate harvest maturity and could support sugar mill operation for up to three additional months. However, sweet sorghum planted in early May and harvested at the HD stage produced 30 to 210% more fermentable sugar than other tested planting dates and maturity combinations. Ratoon crop production was not dependable showing inconsistent tiller growth with resultant low biomass yields. Correlation coefficients of sugar yield with biomass or other quantitative agronomic characteristics were higher than 0.79, while that with brix was only 0.32 (P < 0.0001). Production management in Louisiana from long season cultivars such as M81‐E based on a single harvest 150 to 160 d from planting at the HD stage can provide more biomass and fermentable sugar than can production management targeting a ratoon crop.