Coupling Water Resources and Agricultural Practices for Sorghum in a Semiarid Environment

Water scarcity and changing rainfall distribution have caused uncertainties in relation to agricultural production in semiarid areas. In this context, water reuse for irrigation is a promising alternative, although requiring irrigation and agricultural management. Production of forage plants is strategic for semiarid areas due to their high tolerance to stresses and use as animal fodder. The objective of this work was to evaluate the combined performance of treated wastewater irrigation and mulching on forage sorghum and on soil attributes in Northeast Brazil. Sorghum was cropped in November 2018, three months before the beginning of the hydrologic year, and cultivated over three cycles until April 2019. The experiment was designed with five irrigation depths (60%, 80%, 100%, 120%, and 140% of crop evapotranspiration), and with four soil cover conditions (0% (witness), soil covered with native vegetation, with coconut coir, and with macerated moringa seeds), adopting four replications. Irrigation with treated wastewater promoted linear increases in forage sorghum yield at irrigation depths of up to 140% of crop evapotranspiration. Mulch promoted a 24% increase in productivity in relation to the area where conservation was not practiced, being able to control salinity while also contributing to the higher incorporation of organic matter. Irrigation with treated wastewater had no negative agronomic impacts on soil, once natural rainfall events typical of the Brazilian semiarid region allowed effective salt leaching from shallow sandy soils