Domestic Sewage Effluent’s Used in Fertigation of Forage Planting Chemical and Physical Characteristics

Abstract

Fertigation of agricultural crops using raw domestic sewage (RDS) has proven to be an excellent choice as opposed to conventional treatment. In this context, this work’spurpose was to evaluate the characteristics of the RDS to be applied in elephant grass fertirrigation as to its possible nutrients and pollutants. RDS was submitted to chemical (pH, COD, BOD5, Na, macronutrients and micronutrients) and physical (EC, TS, TFS and TVS) laboratory analyzes. Sodium was the referential chemical element for the definition of the RDS’s sheet to be applied to the ground, which was 215 mm of RDS at 26 cultivation weeks. NTK and P concentrations in RDS were 137 and 19.9 mg L-1, corresponding to the applied load of 296 and 43.9 kg ha-1 respectively, values that can be considered high. Furthermore, the mean concentrations of BOD5 and COD were 433 and 743 mg L-1 respectively, which leads to a COD/BOD5 ratio of 1,7, signaling a high biodegradability of organic matter in the RDS, indicative of good quality for agricultural purposes. Based on the applied sheet, it can be concluded that the RDS provided the availability of sufficient quantities of nutrients, ensuring good conditions for forage grass development.