THE INFLUENCE OF IRRIGATION WITH TREATED DAIRY WASTEWATER ON THE YIELD AND QUALITY OF TABLE BEET

Abstract

Abstract. This work was conducted to evaluate the level of total soluble solids and the yield of the table beet irrigated with of the dairy treated effluent and with different irrigation depths. The experiment was conducted in a greenhouse (210 m 2 ), near of the dairy effluent treatment plant of the University of SA£o Paulo, located at Pirassununga, Brazil. The treatments consisted of three types of water: (1) Anaerobic Effluent – ANE; (2) Aerobic Effluent – AE; (3) Treated rainwater – RW. Three different irrigation depths were used, 50, 100 and 150 % of the crop water demand. All these treatments were applied combined with 50% of the mineral nitrogen fertilization recommended for the table beet. Apart from these, there was a control (table beet with 100% of the nitrogen fertilization recommended, irrigated with water and irrigation depth equal to 100% of the crop water demand). The use of wastewater and the higher irrigation depths promoted differences in the evaluated parameters. Comparing the treatments, it is possible to note that the table beet development was most favorable when irrigated with ANE and AE. The irrigation with ANE was superior in all irrigation depths compared to other treatments (AE and RW). This indicates the importance of differentiating the source of available nutrients (particularly nitrogen) in the wastewater. The level of total soluble solids were not affected by water quality, but were reduced with the increasing of irrigation depths applied with treated dairy wastewater. However the obtained values did not reduce the table beet quality.