Eficiência do reúso de água cinza no desenvolvimento do capiaçu no semiárido brasileiro.

Abstract

Although the "drought" phenomenon is natural, Brazilian society has created programs and/or institutions to face/combat the effects of drought. "Ensuring current and future generations the necessary availability of water, with quality standards appropriate to their respective uses." Water reuse presents itself as a viable alternative to meeting non-potable demands and can be implemented in homes, agricultural production and a variety of activities affected by water scarcity. Therefore, the objective of this study was to evaluate the efficiency of reusing gray water in the irrigation of BRS capiaçu in agro-industrial systems in the Brazilian semi-arid region. The research was carried out using gray water and water supply at the Center for Agro-food Science and Technology - UFCG, located in the municipality of Pombal, state of Paraíba. Initially, daily irrigation with water supply occurred until the BRS Capiaçu buds developed, for 10 days. After this phase, the treatments received surface and subsurface irrigation with supply water and gray water. 10-liter buckets were used, applying 4 buckets per water treatment close to the culm (surface) and through a 100 mm tube (subsurface). Irrigations were carried out every other day at 5 pm, over 90 days. The experiment consisted of 3 blocks of repetitions, totaling 12 experimental units measuring 2.0 x 1.50 x 1.50 meters. Irrigation of the BRS Capiaçu cultivar, using supply water and subsurface gray water, obtained satisfactory results. However, caution must be taken when using wastewater due to the high levels of salts present. In the case of gray water, it can pose risks to the soil and crops if there is no periodic monitoring of soil analysis and irrigated water. BRS Capiaçu is a well known livestock forage, the most used in Brazil, due to its nutritional value, when compared to other elephant grass cultivars. The irrigation of Cultivar BRS Capiaçu, carried out with supply water and gray water subsurface in the blocks through a 100 mm pipe, was satisfactory. In this way, the reuse of gray water proves to be a low-cost alternative, which can be used in regions with high water scarcity and with populations with low purchasing power living in rural areas.