Mulch Evaluation and Managing Vegetation in Medians: Final Report

About the report:

Experiments show best erosion control and vegetation with straw mulch, all wood or paper fiber mulches being suitable tacking agents at rates of 750 lb./A. When used alone, standard wood fiber generally gave better vegetative cover than paperfi er; however, all fiber mulches are acceptable when applied at 1500 or 2500 lb/A. Sparse grass stands in medians were improved before and after one spring mowing when applying readily available N at 50 or 100 lb./A; during late winter, responses from urea formaldehyde (slow release nitrogen) were nil. Grass canopies along mowed areas often become thin and weedy because of low soil fertility; such grass canopies may be improved by N fertilization or permanently by seeding persistent perennial legumes, crownvetch (Coronilla varia), flatpea (Lathyrus sylvestris) and/or sweetpea (Lathyrus latifolius). Legumes may be successfully established when broadcast seeded in late winter-early spring into existing sod with a loose, roughened soil surface or by no-till sod seeding when legumes are placed in the soil. In dense grass sods, herbicides banded over the rows usually improve stands and growth of legumes. With dense stands of temperate grasses, as tall rescue, it is practical to mow once during the season when delaying the first mowing until about 50% of the seedheads emerge. Sparse grass canopies with weedy annual and perennial species need to be mowed a second or third time to maintain a "groomed" appearance. Principles of mowing temperate grasses and grass-legume mixtures are given. Sampling soil in areas in need of renovation is strongly recommended to ascertain the lime, phosphorus and potassium needs. Sampling studies show large variations in the mineral nutrient status among and within cut and fill slopes and medians. Soil analyses reduce renovation costs by applying only needed fertilizers. Four legumes, crownvetch, flatpea, sweetpea, and sericea lespedeza, are persistent perennials for cut and fill slopes in the Piedmont, Coastal Plain and Mountainous regions of Virginia when not mowed. These legumes persist indefinitely after applying lime, phosphorus and potassium liberally for establishment.

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