Kim Patricia May Mosse

Physicochemical and microbiological effects of long- and short-term winery wastewater application to soils

Application of winery wastewaters to soils for irrigation of various crops or landscapes is a common practice in the wine industry. In this study, we sought to investigate the effects of this practice, by comparing the physicochemical and microbiological soil properties in paired sites that differed in having had a history of winery waste application or not. We also compared the effects of a single application of untreated winery wastewater, to application of treated winery wastewater (sequencing batch reactor) and pure water to eliminate the effects of wetting alone. Long-term application of winery wastes was found to have significant impacts on soil microbial community structure, as determined by phospholipid fatty acid analysis, as well as on many physicochemical properties including pH, EC, and cation concentrations. (13)C NMR revealed only slight differences in the nature of the carbon present at each of the paired sites. A single application of untreated winery wastewater was shown to have significant impacts upon soil respiration, nitrogen cycling and microbial community structure, but the treated wastewater application showed no significant differences to wetting alone. Results are discussed in the context of sustainable winery wastewater disposal.

Winery wastewater inhibits seed germination and vegetative growth of common crop species.

The ability to reuse winery wastewater would be of significant benefit to the wine industry, as it could potentially be a cost-effective method of wastewater management, whilst at the same time providing a valuable water resource. This study investigated the effects of different dilutions of a semi-synthetic winery wastewater on the growth and germination of four common crop species in a glasshouse study; barley (Hordeum vulgare), millet (Pennisetum glaucum), lucerne (Medicago sativa) and phalaris (Phalaris aquatica). The wastewater caused a significant delay in the germination of lucerne, millet and phalaris, although overall germination percentage of all species was not affected. Vegetative growth was significantly reduced in all species, with millet being the most severely affected. The germination index of barley correlated very highly (r(2)=0.99) with barley biomass, indicating that barley seed germination bioassays are highly relevant to plant growth, and therefore may be of use as a bioassay for winery wastewater toxicity.