Impacto da água residuária de curtume no crescimento inicial da Atriplex nummularia Lindi cultivada em luvissolo.

Abstract

Various human activities can lead to soil degradation. In the livestock industry, the leather tanning process is highlighted as a potentially degrading activity, due to the deposition of the residues in the different stages, initiated with salting that generates wastewater of high organic load, usually deposited in the areas surrounding the slaughterhouses. The search for mechanisms to minimize the impact caused to the soil by the activity is essential, being the possibility of the use of plants tolerant to the high levels of salinization an important strategy of phytoremediation, like the herb salt (Atriplex nummularia L.). The objective of this research was to verify the impact of irrigation with tannery waste water on the initial growth of the salt grass and to carry out preliminary soil assessment of the brine disposal area. A case study and a field survey in Sumé (PB) were carried out, which consisted of soil characterization of the area and establishment of salt grass seedlings, irrigated with different dilutions (100%, 50%, 20%, 4,0% and 0,8% brine). The atriplex seedlings were planted in 5L pots, using a Luvisols, without addition of organic matter. The results of the soil analysis indicated that the chemical attributes of the soil of the salting area of the leather present high levels of sodium, organic matter and electrical conductivity at the site and in the surroundings and that there was an increase of the salts contents in the soil of the vessels, especially in those receiving irrigation with 100%, 50% and 20% of brine (Na 161.7 - 91.3 - 22.6 cmolc dm - 3 and EC 21.13 - 14.42 - 10.5 dS m - 1 respectively). Although with reduced cultivation time, it was possible to show that Atriplex nummularia showed potentials of expressive tolerance to the development in soils of areas contaminated by the salinity of the leather salting, responding to the increase of salinity of irrigation water when considering the increase of production of biomass and the root system.