Waste stream utilisation for sustainable viticulture.

Field trials were established at four vineyards in January 1999 to evaluate the effects of four mulch mixtures on different soil and plant parameters. Mulches were made from wine industry and other commercially available plant and animal wastes. Soil, grape petioles, grape leaves and grape juice were analysed over three seasons. The mulches applied released considerable quantities of nutrients, which were available for use by the grapevines. Generally, the type of mulch used had little impact on the parameters that were measured and the greatest differences occurred between non-mulched and mulch treatments. Soil pH showed an increase at three of the four sites after application of mulch. Soil phosphorus increased moderately at one site and substantially at the other three sites in the first year and soil potassium levels increased dramatically at all sites in the first year. After the application of mulches in 1999 the petiole nitrate levels increased dramatically at all sites, however there were no differences in the second year. In the third year petiole nitrate levels were again high indicating that the differences between years was probably largely attributable to differences in rainfall received among the three seasons. Petiole potassium levels also increased after the application of mulch, however the increase was nowhere near as large as the increase in soil potassium. The use of mulch increased leaf nitrogen and potassium levels but not phosphorus levels. The use of mulch did increase juice potassium, however there was greater seasonal and site variation than variation due to the effect of mulch.

Seroprevalence of human immunodeficiency virus infection in a prenatal population at high risk for HIV infection.

To determine the seroprevalence of human immunodeficiency virus infection in prenatal patients at high risk for HIV infection we tested 513 women from December 1985 through July 1987 at an inner-city hospital in Atlanta, Georgia. Demographic and HIV risk information was collected from all seropositive women. Twenty-nine (6%) of the 513 women tested were positive for HIV on enzyme-linked immunosorbent assay and Western blot analysis. Twenty-six (90%) of seropositive women gave a history of intravenous drug use. Two (7%) had sexual partners known to have AIDS or AIDS-related complex (ARC), and one (3%) was Haitian. Seropositive women were at remarkable risk for other sexually transmitted diseases. The majority of pregnancies ended in term births. This serosurvey defines an obstetric population with a high seroprevalence, and has stimulated us to institute routine voluntary antepartum screening for HIV.