Cultivo de tilápia e uso de seu efluente na fertirrigação de feijão vigna.

Abstract

The activities of water use involve complex interactions, where an activity causes impacts, both positive and negative, in other activities. The management of water resources within the concept of multiple use has the objective of concurrent and integrated exploitation, in which relations between the products generated are complementary. The concept of integrated agricultureaquaculture has been successively redefined to accommodate a range of models and systems applications. In several countries, the integrated agriculture-aquaculture is being developed fully for several years and with many models. In Brazil, these integrated production systems are recent and require research to determine the best form of exploitation. The objective of this study was to develop and disseminate the multiple use of water resources in the Northeast, through the use of water for fish farming in fertigation of crops. The study was conducted at UEP-Parnaiba, Embrapa Meio-Norte.The part regarding the fish culture, species worked was Nile tilapia (Oreochromis niloticus) Chitralada, and the crop grown was cowpea (Vigna unguiculata (L.) Walp), BRS Guariba. In the experiment with tilapia, two factors were studied: stocking density (28 fish m"3-Dl and 56 fish m"3-D2) and daily renewal rate of water (200 %-Vl, 400 %-V2, 600 %-V3 and 800 %-V4). The fish were reared in tanks with 3 m3 and cycle of 140 days. In the experiment with cowpea two types of water were used for irrigation (AO- irrigation water of the UEP-Al-Parnaiba and effluent from fish culture), combined with four doses of chemical fertilizers (Fl-100 % fertilization, F2-66 % fertilization, F3-33 % fertilization and F4-0 %). The integrated agricmture-aquaculture production system with cowpea cultivation and Nile tilapia fish optimizes the use of water resources and agricultural, exploitation with the acquisition of two productions from the water sharing. The best fish production was obtained in the treatment of the 56 fish m"3 density, with daily water renewal rate of 400 %, which also produced the highest levels of nutrients in the effluent. The indices of growth and yield components of the cowpea, BRS Guariba, crop did not change because of the doses of chemical fertilization and the use of effluerit from tilapia.