Salinity, sodicity and microbiological properties of an Ultisol cultivated with saltbush and irrigated with saline effluents

The objective of this work was to evaluate the effects of irrigation with saline effluents, from red tilapia production ponds, on chemical and microbiological properties of soils cultivated with saltbush (Atriplex nummularia Lindl). Four areas were used, from which two were irrigated with saline waste and cultivated with A. nummularia, during one and five years. The other two areas were not irrigated, and one was cultivated with natural vegetation and the other with the halophyte. The parameters related to soil salinity and sodicity were evaluated, as well as the following characteristics: microbial biomass carbon (Cmic); Cmic/organic carbon; the activity of acid and alcaline phosphatase enzymes, beta-glucosidase, protease, L-asparaginase and L-glutaminase. The addition of salts affected the physical and chemical properties of the soils irrigated with saline effluents, with a tendency to salinization and sodification. The salinity affected the microbiological properties of irrigated soil, but the cultivation with the halophyte improved the production of the studied enzymes. A. nummularia cultivation in areas that received saline effluents from irrigation improves soil fertility and microbiological properties, but does not prevent salinity.

Atriplex nummularia; carbon microbial biomass; soil enzymes; physical properties; chemical properties

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