Land use intensity: effect on earthworms population and litterbag decomposition.

GIMÉNEZ, ROSANA; JULIAN, P.; FUCHS, JULIO S.; KESTEN, EVA

Curitiba - Paraná – Brazil

Congreso; 15th International Colloquium on Soil Zoology; 2008

Positivo University

<!-- /* Style Definitions */ p.MsoNormal, li.MsoNormal, div.MsoNormal {mso-style-parent:""; margin:0cm; margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Times New Roman"; mso-fareast-font-family:"Times New Roman"; mso-ansi-language:ES; mso-fareast-language:ES;} p.MsoBodyText, li.MsoBodyText, div.MsoBodyText {margin:0cm; margin-bottom:.0001pt; text-align:justify; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Times New Roman"; mso-fareast-font-family:"Times New Roman"; mso-ansi-language:ES-MX; mso-fareast-language:ES;} @page Section1 {size:612.0pt 792.0pt; margin:70.85pt 3.0cm 70.85pt 3.0cm; mso-header-margin:36.0pt; mso-footer-margin:36.0pt; mso-paper-source:0;} div.Section1 {page:Section1;} --> Two systems in the south of Buenos Aires province were studied. The lower intensity use system corresponded to 17 years Lucerne pastures for livestock feeding. In the higher intensity use landscape, 15 years of vegetable production with carbendazim applications took place but two years before the initiation of this study it changed to Lucerne pastures. Four plots of each system were evaluated during 24 months. Earthworm density and total biomass were determined. The earthworms were expelled using formalin and hand sorted on the surface. A biomass index was calculated. We used the litterbag method with 0.2 and 3.4 mm mesh bags to study organic matter decomposition. The 80 bags used were recovered at 0, 6, 12, 18 and 24 months and the mass loss was evaluated. Aporrectodea trapezoides, A. turgida and Metaphire californica were found in both systems. Earthworm density and total biomass in the low intensity system were statistically higher than in the high intensity system and strong correlations between biomass index and carbendazim applications, ploughings and years of agriculture were found. Mass loss in litterbags was higher in low intensity system after 12 months. The study illustrates the effects of carbendazim applications and agricultural practices on soil fauna. Index Terms - agricultural intensification, Aporrectodea trapezoides, Aporrectodea turgida, carbendazim, Metaphire californica, organic matter.