How Best Can We Use Biodiversity in Agroecosystems?

Abstract

Agriculture affects biodiversity by replacing nature's diversity with a smaller number of cultivated plants and domesticated animals. Agricultural systems are often artificial ecosystems of genetic uniformity or monoculture. Due to their artificial nature, these systems require constant human intervention, extensive external inputs and use of non-renewable resources. In marginal rural agricultural communities, how can agricultural productivity be increased while altering the trend towards monoculture methods in favour of low-input, conservation-regenerating farming methods? The natural enemy hypothesis supports pest reduction in systems with greater biodiversity. Studies in California over the last twenty years have shown biodiversity to be a key factor in insect pest management. Strategies utilizing alternate hosts and cover cropping have significantly enhanced natural enemy populations. Biodiverse multiple cropping, intercropping, agroforestry and shifting cultivation systems are still practised in traditional farms in Latin America. Non-governmental organizations (NGOs) in Latin America are studying these systems and incorporating this biodiverse approach in their work with rural agricultural communities. Efforts in Mexico, Peru, Honduras and the Dominican Republic are described.