Soil Quality of a Semi-Arid Pasture Irrigated with Reverse Osmosis Wastewater—A Case Study from Northern New Mexico

摘要

Soil quality indicators were assessed in two adjacent fields in northern New Mexico near a reverse osmosis (RO) facility. One field had been cleared of native vegetation, sowed with a pasture mix and irrigated with saline RO wastewater (electrical conductivity (EC) of 2.73 dS/m) (WW) for two years. An adjacent field of non-irrigated, undisturbed native vegetation (NV) that received only natural rainfall was sampled for comparison and assumed to be representative of baseline values. Measurements included mean weight diameter (MWD), dry aggregates > 2 mm (D > 2 mm), dry aggregates < 0.25 mm (D < 0.25 mm), wet aggregate stability, permanganate oxidizable carbon (POXC), soil organic matter, EC, pH, sand, silt and clay contents, and chemical parameters (NO3-N, P, Ca, Mg, Na, Zn, Fe, Mn and Cu). The wastewater irrigated field had more favorable soil quality indicators than the non-irrigated field, presumably due to the pasture mix and irrigation. However, the EC is higher in the WW irrigated field and will affect long-term utilization of the land for cropping, unless good soil salinity management is implemented.