Metais pesados em solos sob aplicação de dejetos líquidos de ...

ABSTRACTDoctorate ThesisGraduate Program in Soil ScienceFederal University of Santa MariaHEAVY METALS IN SOILS UNDER PIG SLURRY APLICATTION INWATERSHEEDS OF SANTA CATARINA STATEAuthor: Jorge Luis MattiasAdviser: Carlos Alberto CerettaCo-advisers: Danilo Rheinheimer dos SantosLeandro Souza da SilvaSanta Maria, october 27, 2006The application of pig slurry in agricultural soils can be an efficient form of nutrients cilcle andone of the best alternative for discard and minimizing his pollutant potential. However, the differencesbetween his composition and the needs of the plants, especially of trace elements, it hinders her morerational use. The composition of the pig slurry is reflex of the feeding type offered to the animals,which usually contains larger amounts of nutrients than the required for the animals. That fact,associate to systematic applications of pig slurry in the soils can cart in accumulations, becomingpollution source not punctual in the environment. The present work was elaborated with the objectivein identifying the possible sources of contamination of the soils with trace elements, to esteem thecapacity of the soils in receiving successive applications of metals and also verify if the soils thatreceive systematic applications of pig slurry with high tenors of metals can in a small space of timeresent problems of environmental contamination.Three studies were conduced in the watersheed Rio Coruja/Bonito and Lajeado Fragosos inSanta Catarina state. In the study 1 it was looked for to evaluate the sources of entrance of traceelements in the environment. In the study 2 it was looked for to evaluate the current state of traceelements in the soils under application and the main attributes of the soils that influence in herretention. In the study 3 it was looked for to evaluate the maximum capacities of retention of traceelements of the soils and the interaction degree with the soils. In the first samples of feeds and pigslurry were collected in 12 properties of each one of the watersheeds and the total amounts of theelements of the feeds were analyzed. In the second study collections of soils were accomplished inthe 12 properties, representative of the three main classes of soils of watersheeds, the total andavailable amounts of trace elements were analyzed in the soils, the mineralogy and the organic matterof the soils. And in the third study they were applied doses of trace elements to the soils to esteem theretention capacity for the elements considered pollutants, it was also esteemed the capacity ofliberation of the elements retained starting from a disturbance.The obtained results show that it is made a super-dosage of trace elements to the swine in thefeeds and these are transferred to the pig slurry, that, allied the great applied amounts elevate thelevels in soils. The attributes of the soils responsible for the retention of the trace elements are notcapable to the systematic reception of the pig slurry, and, the annually applied amounts don't reflectthe amounts found on the soils. The soils of watersheeds didn't reach his maximum capacity ofretention for the elements of larger addition to the soils, even if being these lowers. Therefore, practicethat propitiate to the soils improvement of the attributes responsible for the retention of the traceelements are pressing to reduce the probability of environmental contaminations.Keywords: Pig slurry, heavy metals and watersheeds.