Utilization of biodiversity in agriculture: today and tomorrow

Currently, world agriculture was faced with drastic challenges to produce sufficient food while minimizing negative environmental effects of crop cultivation. Unlike traditional agriculture, which used local biodiversity and species interactions to sustain food production, modern agriculture used fewer high-yield crop varieties and largely ignored species interactions. Modern agriculture relied on chemically-driven modern varieties and irrigation to ensure high production. At the same time, modern high production induced negative environmental effects, pest resistance to pesticides and high agro-production costs. Whether and how biodiversity integrated into modern agriculture was a recent trend of research. Here, we reviewed the researches on the utilization of biodiversity in agriculture in the last decades. We then proposed future researches on intensified development of sustainable global agriculture with integrated biotechnology, precision agro-technology and biodiversity utilization. Unlike natural ecosystems, agro-ecosystem species consisted of productive biota (e.g., crops, forest trees and animals), resource biota (e.g., pollinating insects and crop-related wild species) and destructive biota (e.g., weeds and insect pests). Productive biota cultured by farmers dominated agro-systems and contributed to food production. Thus designing productive biota diversity was critical for biodiversity utilization of agro-systems. Utilization of productive biota diversity in agriculture included applications of genetic, species and landscape diversity. Studies indicated that uses of multi-gene varieties and mixtures of varieties were the key approaches to genetic diversity. This effectively controlled diseases in coffee, barley, wheat and rice crops. Genetic diversity mechanisms controlled diseases via resistant plant pathogen dilution or physical isolation. For species diversity utilization, intercropping and co-culture of crops and animals were the two common approaches. Legume-cereal intercropping and rice-fish co-cultures were the two successful examples of species diversity use in agro-systems. Species intercrops or co-cultures reduced the applications of chemical fertilizers and pesticides and promoted super-harvests. Positive species interactions and complementary resource uses explained why intercrops and co-cultures promoted super-harvests. For example, super-harvests often occurred in legume-cereal intercrops mainly as a result of facilitative root interactions, including nitrogen transfers and nutrient mobilizations. In rice-fish systems, fish reduced rice pests whereas rice moderated fish water environment which in turn enhanced pest removal. This positive relationship between rice and fish resulted in reduced pesticide use. Experiments also indicated that complementary use of nitrogen (N) in rice-fish systems resulted in low N fertilizer use and low N release into the environment. Within agricultural areas, diverse croplands in mosaic patterns maintained natural habitats (e.g., small grassland) and field margins helped develop diverse agro-landscapes. Studies showed agro-landscape diversity potentially provided shelter and alternative foods for resource biota in agro-systems. Although biodiversity utilization in agriculture was successful in many traditional agro-systems, studies on successful integration of biodiversity into modern agriculture were rare. For example, studies were needed in landscape diversity designs for large-scale agriculture. Positive species interactions and complementary resource uses also needed consideration in the development of modern agriculture such as intercrop or species co-culture systems. Field facility for diverse species co-existence needed sufficient construction. New machinery suitable for intercrop or species co-culture systems needed development as well. Information-based precision agro-technology suitable for intercrop or species co-culture systems likewise needed development.