Different Approaches to Assessing Pollution Load: The Case of Nitrogen-Related Grey Water Footprint of Barley and Soybean in Argentina

OLIVERA RODRIGUEZ, PAULA; HOLZMAN, MAURO EZEQUIEL; MUJICA, CLAUDIO RAMÓN; RIVAS, RAÚL EDUARDO; ALDAYA, MAITE M.

Water

MDPI

Año: 2021 vol. 13

Abstract: Agriculture is among the main causes of water pollution. Currently, 75% of global anthropogenicnitrogen (N) loads come from leaching/runoff from cropland. The grey water footprint(GWF) is an indicator of water resource pollution, which allows for the evaluation and monitoring ofpollutant loads (L) that can affect water. However, in the literature, there are different approachesto estimating L and thus contrasting GWF estimates: (A1) leaching/runoff fraction approach, (A2)surplus approach and (A3) soil nitrogen balance approach. This study compares these approachesfor the first time to assess which one is best adapted to real crop production conditions and optimisesGWF calculation. The three approaches are applied to assess N-related GWF in barley and soybean.For barley in 2019, A3 estimated a GWF value 285 to 196% higher than A1, while in 2020, the A3estimate was 135 to 81% higher. Soybean did not produce a GWF due to the crop characteristics. A3incorporated N partitioning within the agroecosystem and considered different N inputs beyondfertilization, improving the accuracy of L and GWF estimation. Providing robust GWF results todecision-makers may help to prevent or reduce the impacts of activities that threaten the world?swater ecosystems and supply.