The use of treated bleached kraft pulp kraft mill effluent on eucalyptus plantation

Abstract

The use of treated pulp mill effluent on eucalyptus plantation appears to be an attractive option for plant nutrition and water supply. It also constitutes a supplementary treatment process or final disposal option for the mill effluent. This study aimed at the investigation and evaluation of the effects of bleached kraft pulp mill treated effluent (BKME) on three typical Brazilian soils used for Eucalyptus plantation. The BKME was characterized and five different application rates, defined according to the load of sodium, were tested in controlled environment experiments (greenhouse). After BKME application over a six month period an expressive increase in the salinity of the studied soils was observed, although no dispersal effects in soil with high clay content were detected. The low content of some nutrients in the BKME, indicated the need for complementation in fertirrigation. In general, the best biomass productivity and plant growth results were obtained in fine textured soil at a loading rate of 6.49 t sodium.ha-I. In general, the good response of the soil-plant system under different effluent application rates showed the possibility of agricultural use of BKME if adequate management practices and monitoring are conducted.