PARENT SESSION
Tuesday, August 8, 8:00-11:30 am
COS 28 - Agroecology
Heritage Ballroom I, Marriott
Presiders: M Laszio
The effects of pasture intensive grazing management on soil community ecology.
Mills, Aaron*,1, Adl, Sina1, 1 Dalhousie University, Halifax, Nova Scotia, Canada
ABSTRACT- A long-term, multidisciplinary study of pasture agroecology, is currently being conducted to examine the relationship between aboveground and belowground functional diversity, and the affects on agroecosytem productivity. The experimental design consists of eight paddocks (blocks), each with four randomized treatments representing different levels of intensive grazing management 1) grazed every rotation followed by clipping and chain harrowing (intensive); 2) grazed every rotation, and clipped only every second rotation (semi-intensive); 3) grazed every second rotation, with no clipping or harrowing (delayed grazing); 4) grazed only once a year, followed by clipping (stockpiling). A community ecology approach is being implemented using samples collected in the spring, summer, and fall seasons. The sampling periods measure treatment effects before, during, and after, the yearly grazing rotation. Analyses show that there were significant (P<0.05) seasonal effects on soil moisture content, nematode diversity and evenness, and flagellate abundance. There were also significant (P<0.05) treatment effects observed with percent bare soil and percent legume content from quadrat samples. Canonical correspondence analysis showed that certain environmental factors, including percent bare soil, pH, and bulk density were associated with plant species diversity, plant functional diversity, testate amoebae abundance, and flagellate abundance. Nematode functional diversity was associated with treatment. These data indicate a response to intensive grazing management. This information will be used to examine the relationship between disturbance, agroecosystem productivity and function, and will be used to promote sustainable pasture management practices.
Key words: pasture, agroecology, biodiversity