Sustainability of the grey water footprint (GWF) for cultivation of onion in the Brazilian semi-arid regions

Abstract

The grey water footprint (GWF) is defined as the volume of freshwater that is required to dilute pollutants to make them harmless. The objective of this study was to evaluate the grey water footprint and its sustainability for onion cultivation in the Brazilian semiarid regions. The work was developed in the Brazilian semi-arid region in an area corresponding to 10 thousand hectares of onion cultivation under surface irrigation. A survey of the main pollutants was carried out, in addition to the environmental conditions of soil and climate, soon after using mathematical models to estimate the grey water footprint and sustainability. The agrochemicals Ronstar 250 BR, Dicarzol 500 PS and Sportak 450 CE are classified as having the highest grey water footprint for onion cultivation in the Brazilian semi-arid region; thus requiring a higher volume of freshwater for pollutants dilution to convert them to harmless. It is recommended to replace these agrochemicals with others of smaller GWF. According to the obtained results, it can be concluded that the grey water footprint is an efficient indicator in monitoring the impact of man on the environment. The semi-arid regions of Brazil classified as sustainable for the cultivation of irrigated onions.

The water footprint of the sugarcane agro-industry in the Northeast region of Brazil

“…Most studies concerning the WF of sugarcane yield a lower value of grey WF than that found in the present study, because the former tend to consider only the effects of pollutants already present in the environment and not the effects of pesticide use. Matos et al (2017), in a study of the WF of onion crops, found onion's grey WF to be 75,078.8 m³ t -1 in the semi-arid region of Brazil where the pesticide Dicarzol 500PS was used. Boff (2016) found that the grey WF of soybean cultivation 7651 m³ t -1 when the herbicide 2,4-D was introduced.…”

Pegada hídrica cinza no cultivo de tomate no semiárido brasileiro

“…Com estes resultados, até a própria precipitação proveniente das regiões de Parelhas e Equador -RN que é de 551 mm, pode ajudar na diluição, evitando desta forma, a utilização de águas oriundas dos reservatórios hídricos. Matos et al (2017), quantificaram a PHC da produção de cebola para a região do Vale do São Francisco, nos estados de Pernambuco, Alagoas e Bahia, e obtiveram valores da PHC para os agrotóxicos Karate 50 EC (1140 m³ t -1 ) e Sportak 450 EC (60750 m³ t -1 ), maiores ao deste estudo. Essa diferença nos valores da PHC, provavelmente, ocorreu devido as características ambientais entre as regiões e também pelas culturas estudadas.culturais.…”