Produtividade e aporte de nutrientes em palma forrageira ‘gigante’ irrigada com água residuária

Abstract

The experiment was installed at the Instituto Federal de Educação, Ciência e Tecnologia Baiano, Guanambi Campus. The forage palm is a xerophilous plant, adapted to high temperatures and water deficit. It is an important forage resource for semi-arid regions during the dry season. The objective of this study was to evaluate the productivity and the nutrient supply in the 'Giant' forage palm irrigated with wastewater, compared to conventional irrigation and fertilization with bovine manure. The treatments were: without fertilization and without irrigation (SA_SI); without fertilization and irrigation with wastewater (0,6 L plant-1 week-1 ) (AR_0,6); without fertilization and irrigation with wastewater (1,2 L plant-1 week-1 , applied once a week) (AR_1,2); without fertilization and irrigation with wastewater (1,2 L plant-1 week-1 , divided in two weekly applications) (AR_2X0,6); with organic fertilization (60 T ha-1 of bovine manure, applied before planting) and irrigation with common water (1,2 L plant-1 week-1 ) (CA_AP_1,2), and with organic fertilization (60 T ha-1 of bovine manure applied before planting), without irrigation (CA_SI). The wastewater used in the experiment was collected in the stabilization pond of the campus and the common water was collected on tubular well installed at the campus. The treatments were arranged in a randomized complete block design, with five replicates. The productivity of green and dry matter, the amount of macro and micronutrients applied in the soil by water and organic fertilizer, the macro and micronutrient contents present in the cladodes tissues, and the macro and micronutrient contents in the soil were evaluated. Green matter yield was higher in irrigated treatments. Regarding dry matter, its value was higher in SA_SI and it did not differ statistically in the others. Bovine manure increased the N, P, K and S extraction / export. The average amount of macronutrients extracted / exported in descending order were K, Ca, N, Mg, S and P.