Uso de resíduos de papel em compostagem agrícola

Abstract

Nowadays, the correct destination of solid waste generated in the urban environment has been the subject of constant debates by civil society and environmental agencies. It is necessary to ensure that the natural resources used can somehow return to the environment and, preferably, that this return is advantageous. The present work aimed to evaluate organic compounds produced from bovine manure with paper waste from school environments, white and printed with black ink. In containers of 6 dm3 three organic composts were produced from bovine manure and white sulfite paper (4: 1 ratio) (RPB), bovine manure and printed sulfite paper (4: 1 ratio) (RPI) and bovine manure (EPC) only. In the organic compounds produced, the Pb and Cd contents were below the limits of quantification of the methodology used. Two consecutive lettuce crops were grown. The first cultivation was carried out in pots of 3 dm3, in a completely randomized design in the 4x3 + 1 scheme with four replications. The treatments were: four doses of organic compound, equivalent to 20, 40, 80, 160 Mg ha-1, three compounds (RPB, RPI and EPC) and the zero dose as additional treatment, without addition of organic compound. The second cultivation was carried out 90 days after the first one, without additional fertilization. In the soil, there was an increase in pH, CTC, COS, P, K Ca and Mg, after 2 consecutive cultivations. The Ni, Cr, Pb and Cd metals were not absorbed by the plant after incorporation of the organic compound into the soil after a period of three months. The use of paper waste from school environments in agricultural compost improved soil properties and increased lettuce production, with the highest yields obtained in the second crop. The results indicate that this type of organic compound has residual effect for a second lettuce crop, being indicated as a soil conditioner and that this technology can be used as final disposal of waste paper.