Effect of textile industry biosolids for soil fertility and sugar cane production

Biosolids are the sludge that comes from an effluent treatment plant, with a significant amount of organic matter and nutrients in its composition that makes it usable in agriculture as fertilizer. Studies have proven the good results that this practice usually brings to the soil, implanted culture and economic viability of cultivation. The present work aimed to evaluate the effect of the biosolid produced by the effluents treatment plant (ETP) of a textile industry to soil fertility and sugar cane production. In this way, an experiment was carried out on an experimental farm in the municipality of Pedras de Fogo-Paraíba, Brazil. The experimental design used was randomized blocks, composed of 6 (six) treatments and two repetitions: without fertilization, conventional fertilization, 1x, 2x, 4x and 8x the dose of biosolid recommended by CONAMA Resolution 375/06, with three repetitions each, totalizing 18 (eighteen) experimental plots. Soil samples were collected at a depth of 0-20 cm and soil fertility analysis were carried out according to the methodology described by EMBRAPA at the Soil Chemistry and Fertility Laboratory of the Agricultural Sciences Center of the Federal University of Paraíba. The soil of the experimental area was classified as Arenic Orthic Ferroluvic Spodossolo, of sandy texture, low natural fertility, poor drainage and medium organic matter content, with presence of impediment layers and high risk of contamination of the water table and flooding. Based on the results it was observed that the areas with application of biosolids had a higher availability of phosphorus, thus, this element favoured the supply for plant growth in these plots. For the pH results, values between 6.4 and 6.8 were found, though did not change the availability of nutrients for the culture. Regarding maturation, it was observed that there was equal maturation in all plots with the use of biosolids. Regarding the amount of organic matter in the soil, it was observed that there was no improvement in this parameter. This significant fall in organic matter may have occurred due to leaching, once the region where the experiment was located had extended periods of rain. The use of biosolids showed as a viable fertilizer, providing essential nutrients, nitrogen and phosphorus, to the development of the plant in the Spodossolo da Paraíba.