In situ Field Capacity in Brazilian Soils and a Derived Irrigation Management Practice Based on Water Suction

Field capacity (FC) is a fundamental parameter in soil and water engineering hydrologic modeling. Despite its relevance, the situ determination of this not standardized by indirect methods dubious. This study presents method calculation FC corresponding suction (hFC), using van Genuchten equation for retention pedotransfer function Ottoni Filho et al. (2016) FC. The methodology was applied to HYBRAS, database hydrophysical data Brazilian soils with 1,075 samples from 15 states. hFC were confirmed depend on textural class pedogenetic origin (weathered unweathered soils). Our analysis justified why must be determined based only single predetermined value. A simplified proposed management irrigated through root zone mode confidence interval values groups formed classes pedological nature. Various statistical calculations are presented these groups.