Uso da água residuaria doméstica tratada e adubação fosfatada no cultivo da moringa oleífera lam.

Abstract

Water reuse is necessary due to water scarcity in various parts of the world. The use of wastewater in agricultural irrigation is already a reality, with favorable results for the growth and development of plants. However, it is necessary to adopt adequate management to avoid damage to the soil and damage in the cultivation of plants that may have nutritional and commercial importance, as is the case of the Moringa oleifera Lam plant. Thus, this research used domestic wastewater treated using Upflow Anaerobic Reactors and Sludge Manta (UASB) in different proportions for irrigation in the cultivation of the Moringa plant oil Lam. comparing with the control treatment (drinking water) plus the interaction with phosphate fertilization (7.9 gkg-1) of phosphorus through fertigation using Purified monoammonium (MAP) phosphate (Dripsol®). For this purpose, the experiment was carried out between the months of July and November of the year 2019 in a greenhouse belonging to the Experimental Station of the Instituto Nacional do Semiárido - INSA municipality of Campina Grande - PB. The design adopted was a randomized block with four replications. The factors under study were arranged in a 5 x 2 factorial scheme in which the treatments were composed of a combination of two factors, factor 1: five different levels of wastewater concentration diluted in drinking water for the irrigation of Moringa (25%, 50%, 75%, 100% and water supply as a control treatment). Factor 2: two fertilization managements (AF - phosphate fertilization and SA - without phosphate fertilization). The growth characteristics of the plants (height, stem diameter, and a number of leaves) from 15 to 110 days after the beginning of treatments (DAIT), levels of Chlorophyll A, B, Total, and Carotenoids at 90 DAIT were evaluated. Nitrogen, phosphorus, and potassium present in Moringa leave at 90 DAIT, absolute growth rate and relative growth rate in plant height from 15 to 110 DAIT, fresh matter and dry matter content of the aerial part of Moringa, rate of the absolute and relative growth of the fresh and dry matter of the aerial part of the plants, root / aerial part of the plants and, finally, the determination of nutrient input and changes in soil chemistry at the end of the treatment application. In the results, it was verified that the use of wastewater (AR) contributed to the growth of the plants, reaching the maximum value with the concentration of 75% of AR, in that same concentration reached the highest N content and with 100% of AR the higher levels of P and K in the aerial part of the plants, in the absolute growth rate in the height of the plants, fresh matter and dry matter of the aerial part, reached the highest level with 75% of RA. The chemical changes and the nutrient content in the soil were most influenced by 75% of wastewater in irrigation. The treatment with phosphate fertilization had better results than the treatment with wastewater in the growth parameters, increased the content of N and P in the aerial part of Moringa, increased the rate of absolute and relative growth in the height of the plants, increased the production of fresh matter and dry matter in the aerial part of the plants and modified the chemical composition of the soil. Both RA and AF influenced the root / aerial part of the plants.