Chemical changes in the soil after irrigation with effluents and phosphate fertilization cultivated with <i>Moringa oleifera</i> Lam.

Abstract

The interest in the use of wastewater has grown, due to the limitation of good quality water, especially in the semi-arid region. The objective was to analyze the chemical alterations of soil irrigated with wastewater and phosphate fertilization, in the production of seedlings of Moringa oleifera Lam. The experiment was installed in a greenhouse, in the forest nursery of the Experimental Station Prof. Ignácio Salcedo from the National Institute of the Semi-Arid Region – INSA, Campina Grande – Paraíba. A randomized block design was adopted, factorial arrangement 5 x 2, with four replications, with five percentages of treated domestic wastewater, diluted in supply water (25%; 50%; 75%; 100% and treated supply water ), associated with two nutritional factors (PA – phosphorus fertilization and SA – without fertilization). At 110 days after conducting the treatments, the following soil characteristics were evaluated: hydrogen potential, electrical conductivity, calcium, magnesium, sodium, phosphorus, potassium, sum of bases, aluminum, hydrogen, sulfate, cation exchange capacity and organic matter . The use of phosphate fertilizer contributed positively to the phosphorus, carbon, organic matter and cation exchange capacity of the soil. The increasing percentiles of wastewater leveraged the sum of bases and the cation exchange capacity, simultaneously promoted the increase in Na⁺, Al, H⁺Al contents and in the electrical conductivity of the soil saturation extract.