Allelopathy in sustainable agriculture and forestry

Abstract

Simply put, allelopathy refers to an ecological phenomenon of plant-plant interference through release of organic chemicals (allelochemicals) in the environment. These chemicals can be directly and continuously released by the donor plants in their immediate environment as water leachates volatiles in the air or root exudates in soil - or they can be the microbial degradation products of plant residues. Allelochemicals may interfere with survival and growth of neighboring or succeeding plants, and may also discourage insects and pathogens. Black walnut, eucalyptus, sunflower, sorghum, sesame and alfalfa are common examples of plants with allelopathic properties. Likewise, staple crops such as rice, wheat, barley and sorghum also exhibit allelopathic characteristics. Knowledge of this form of plant interference on other plants and on disease causing organisms has been used in agriculture since prehistoric time. By manipulating cropping pattern and sequence through mixed cropping or crop rotation, farmers have been able to maintain sustained productivity. However, use of numerous agrochemicals - including a wide range of herbicides, pesticides, fertilizers and genetically modified high yielding crops - has become the characteristic feature of modern industrial agriculture. Not only is the sustainability of crop yield called into question in this form of agriculture, but the extensive long-term and often irreversible environmental degradation including ground water contamination and food safety associated with industrial agriculture are now serious concerns worldwide. This book reports on the latest advances in allelopathy through the contributions of leading scientists in the field. The book addresses the history of allelopathy, the science of allelochemicals, and the application of allelopathy in agriculture and forestry. An emphasis on both methodology and application makes Allelopathy a truly practical reference for scientists, researchers and students of plant science, agriculture, forestry, terrestrial ecology and environmental science. © 2008 Springer Science+Business Media, LLC. All rights reserved.