The effects of land use intensification on soil biodiversity in the pasture

Abstract

A long-term multidisciplinary study of pasture agroecology is currently being conducted in Nova Scotia, Canada. The objective is to examine the relationship between above -ground and below-ground functional diversity, and the effects on agroecosystem productivity. The experimental design consists of four treatments of decreasing land use intensity, applied in the context of management intensive grazing. Treatments include: (1) clipping and harrowing following each grazing rotation (intensive); (2) clipping only once following the first defoliation; (3) grazing every second rotation; (4) grazed only once a year (extensive). Samples were taken from each treatment once during May, July, and September 2005. Edaphic characteristics and plant diversity were measured, as well as microarthropod, nematode, protist, and bacterial functional group diversity and abundances. Significant (P < 0.05) effects of treatment were observed on percentage of bare soil, plant species and functional diversity, and bacterial functional diversity. There were also significant (P < 0.05) negative correlations observed between treatment, and both testate amoebae and flagellate abundances. The information obtained from this study may be used to test the relationship between biodiversity and land-use intensity, and how productivity is affected in the pasture. Key words: Soil ecology, pasture management, sustainable agriculture, biodiversity, forage grazing