Resumo

JIMENEZ, L; NOGUERA, N  e  LARREAL, M. Productivity changes in a degraded Ultisol of the Machiques Colón, by the application of cattle dung. Rev. Fac. Agron. [online]. 2004, vol.21, n.3, pp.246-259. ISSN 0378-7818.

In order to evaluate the effects of cattle dung as organic amendment on the soil productivity of a degraded Ultisol, a field trial in a farm located in the Machiques-Colón dry tropical forest was performed. A randomized block design, with six repetitions, and split plot arrangements 2x3 (2 slope degree 0-3%, 3-8% and three levels of cattle dung 0,60,120 Mg ha^-1, using as a control crop Brachiaria humidicola grass. One year later after the application, aerial biomass (BA) and radical (BR) were determined and the soil profile were characterized up to one meter depth, being the physical variables: available water (AU), bulk density (Da), clay percentage (%A), structure type (E); and chemicals soil reaction (pH), organic carbon (CO), and aluminum saturation (SA). The observed values were applied to a soil productivity index model in order to determine productivity index (IP). According to the results BA and BR were significantly high for the amendment levels. AU was not affected by the amendment, E was improved with the organic amendment, pH and CO significantly increased with the organic amendment and S.A values were significantly low. IP showed differences between slope degrees and amendment levels, being higher for 0-3% slope degree and for amended plots. The physical and chemical changes reached with the amendment, it means that IP was improved, however it was limited by the subsoil. In the future, trials must combine vertical tillage system and deep amendment incorporation.

Palavras-chave : productivity; soil degradation; organic amendment.