Nutrient Contents in a Cerrado Oxisol Fertilised with Swine Liquid Manure under an Environmental Conservation Perspective

Aims: The objective of this work was to evaluate the distribution of nutrients in the layers of a Cerrado oxisol, fertilised with liquid swine manure compared to the values of these nutrients established by the Conama (National Council of the Environment) for the conservation of quality from soil.

Study Design: The experiment was carried out in a randomized block design with four treatments, in five replications, 0, 10, 20 and 30 m3 swine net waste ha-1, applied eight times, corresponding to the accumulated volumes of 0, 80, 160 and 240 m3 swine net waste ha-1, respectively.

Place and Duration of Study: The study was conducted at the Rio Verde Foundation (13º03 '01 "S and 55º54' 40" W), from February 2014 to January 2015.

Methodology: The experiment was composed of 20 experimental units with dimensions of 11.0 m in length and 3.5 m in width. This swine liquid manure (DLS) waste was previously arranged in a stabilisation pond to conform to the microbiological standards of organic waste required by Conama. Soil samples were collected with depths in each plot to evaluate the nutrient contents.

Results: The net residue of swine manure influenced the total nitrogen contents in the layer of 0.10 to 0.20 and Fe in the layer of 0.20 to 0.40 m. From the environmental point of view, total nitrogen (NT), phosphorus (P), copper (Cu) and zinc (Zn) contents were below the values established by Brazilian environmental legislation for soil quality conservation.

Conclusion: In general, nutrient content in the profile of the Cerrado oxisol was not affected by the successive applications of swine net waste in the three soil layers, in the sense that there is an immediate concern that the content is above the critical environmental limit established by Conama.