Using ion exchange resins to monitor nitrate accumulation and leaching in remote semiarid ephemeral stream beds

This data was collected to test the applicability and efficiency of resin samplers and resin bags to monitor nitrates (NO3-N) in two small semi-arid intermitent flow catchments in Northwestern Mexico. Resin samplers were installed below the river bed and remained there for five months to capture NO3-N leachate during the summer rains. Resin bags were anchored in rock outcrops upstream of the resin samplers before the onset of the summer rainfall season. Bags were replaced every two weeks for four months to capture pulses of NO3-N concentrations in ephemeral streams. Results of the resin samplers found a difference of up to 12 kg ha-1 season-1 between the two catchments. The resin bags showed a higher accumulation of NO3-N concentrations in the catchment with lower vegetation cover (160.35 mg L-1 season-1) compared to the one with higher vegetation (67.88 mg L-1 season-1). Measured nitrate fluxes at both sites responded to rainfall pulses recorded during the monitoring period. Resin samplers and resin bags demonstrated an efficient way of determining spatio-temporal nitrate fluxes in semi-arid ecosystems in remote areas that are difficult to access, monitor, and collect data.