Desenvolvimento E Produtividade Da Cana-De-açúcar No Ciclo Da Cana-Planta Com Aplicação De Efluente De Esgoto Tratado Via Gotejamento Subsuperficial

The increasing world demand for sugar and bioenergy drives sugarcane production to high standards.Since the plantations grow toward regions of low hydric resources, the application of treated sludge is identified as an alternative for hydric supply, contributing, that way, to the sustainability of the sector.Water reuse in Brazil is a quite recent practice which does not account with regulations to support an adequate application and disposition.Sludge effluents constitute important environmental problems (water bodies pollution), social problems (health risks) as well as economic problems which should be studied to generate laws to contribute to negative impacts mitigation or diminution of these kinds of effluents in the environment and in the society and the country annual expenses to revert soil and water resources pollution.However, only little information associated to drip subsurface application effects on sugar cane crop productivity and development is available.Based on what it has been exposed before, this research work intends to evaluate the treated sludge irrigation as applied by means of subsurface drip irrigation technique on the RB86-7515 sugar cane vegetative and productivity development on the cane plant cycle in the Campinas, São Paulo region.Treated sugar cane plants (with two water qualities, i.e., treated sludge effluent and superficial reservoir water) agronomic and technological parameters have been determined for two distinct dripping tape installation depth (0.20 and 0.40 m).Agronomic parameters have been measured 303 days after the plantation, meanwhile the technological analyses were carried after 358 of the plantation.Treatments did not show significant influence on the agronomic plant development if compared with the non-irrigated treatment.Regarding productivity, T4treatment (irrigated with treated sludge effluent, fertirrigated and with dripping tape positioned at the depth of 0.4 m) exhibited the highest estimated value (281 t ha -1 ) surpassing the non irrigated treatment by 47 t ha -1 .However, treatment T4 reached an average recoverable total sugar of 125 kg ha -1 , which was lower of the non-irrigated treatment by 10 kg ha -1 and also lower of the treatment with superficial reservoir water, fertirrigated and with the dripping tape positioned at 0.20 m by 35 kg ha -1 .Irrigation with treated at the depth of 0.4 m at the intense growth level did not promote the increase of the agronomic as well as of the technological sugarcane attributes associated to the RB86-7515 sugarcane variety.The average productivity increase was of 17% on the cane plant cycle as compared with the dry xiii (sequeiro?)crop with conventional fertilization when the treated sludge efluente together with the irrigation the fertilization carried with subsurface dripping positioned at 0.4 m.