Water footprint of irrigated rice in the state of Rio Grande do Sul, 2019/2020 crop.

Agricultural production is the practice that uses the most water on the planet, especially the irrigated agriculture, which represents a large part of this demand. As well as the quantitative issue, adequate quality is essential to meet the demands of the crop and its return to the water sources, in a way that does not cause damage to the environment. To measure this consumption, the expression "water footprint" emerged. The water footprint seeks to quantify the demand for water incorporated into products. This paper aims to determine the amount of water used to produce irrigated rice in six rice growing regions in the state of Rio Grande do Sul (RS), in the 2019/2020 crop. The mentioned regions are represented the municipalities of Uruguaiana (West Border), Dom Pedrito (Campanha), Santa Maria (Central Region), Camaquã (Internal Coastal Plain), Porto Alegre (External Coastal Plain), and Rio Grande (South Zone). Climate data from the analyzed regions, during the plant cycle, and productivity values in the crop in question were used. Values of 1187 m3 t-1 were found for WB, 1347 m3 t-1 for CA, 1058 m3 t-1 for CR, 783 m3 t-1 for ICP, 1115 m3 t-1 for ECP, and 1066 m3 t-1 for SZ. For the state of Rio Grande do Sul, an average water footprint was obtained in the 2019/2020 crop of 1093 m3 t-1 .