Effects of pulpmill effluent irrigation on the distribution of elements in the profile of an arid region soil

A comparison was made between the distribution of nitrogen, phosphorous, sodium, calcium, magnesium, cadmium, electrical conductivity and pH in the top 2.5 m of soil in two adjacent fields in Northern Arizona. One field had been irrigated with pulpmill effluent for 15 years. The adjacent field had never been irrigated. Saltbush plants, Atriplex canescens (Pursh) Nutt. growing in the two fields were compared for differences in sodium, magnesium, calcium, nitrogen and phosphorus content. Overall concentrations of all measured elements except calcium and cadmium were significantly elevated in the soil that was irrigated with effluent. Sodium concentration and pH were elevated in the upper soil horizon, whereas phosphorus concentrations were elevated uniformly. Differences in electrical conductivity and magnesium concentrations between the effluent-irrigated field and the unirrigated field increased with depth. Saltbush plants sampled from the irrigated field had higher concentrations of phosphorus and sodium, and lower calcium concentrations than plants sampled from the unirrigated field. This soil could be a good repository for sodium, however, the nutrient content of the resident saltbush population was affected. Other tested elements appeared to leach readily.