Diagnosis of the quality of the waters from the micro watershed of the Angico River for irrigation purposes

Abstract

The present work accomplished a diagnosis of the quality of the surface and underground waters from the micro watershed of the Angico River, aiming to evaluate its use for irrigation. During a period of 11 months of research samples of water were collected fron 9 sources, corresponding to 5 tubular wells with weather vanes, 2 amazon wells and 2 big waterholes in the stream bed. From the 77 samples of water collected, only two sources presented values of the pH (8.60 and 8.89) above the recommendation of the classification of the UCCC (1974). For irrigation, water of excellent quality does not exist in the micro watershed of the Angico River, where the different sources presented low, moderate and severe use restrictions, regarding the salinity risk, however without any restriction of its use as for the risk of the sodification and/or permeability of the water into the soil. The nine studied sources are not appropriate for use by the sprinkler and surface irrigation methods, considering the evaluations of the chloride and sodium parameters which indicated low, moderate and severe restrictions of use.

Key words:
salinity; sodicity; irrigated agriculture