Modelling nutrient flux and interspecies root competition in agroforestry interplantings
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Nutrient competition between interplanted species is investigated using mechanistic modelling. Though tree and crop plant roots may occupy the same soil volume, nutrient competition is seen to be dependent on soil supply mechanisms. Model simulations illustrate the effects of nutrient diffusion rate, mobility/soil interaction, root diameter, soil moisture content, and rooting density on nutrient concentration gradients governing uptake adjacent to plant roots. These factors, unique for each nutrient and soil, combine to determine the potential for competition in agroforestry plantings. Nutrient competition is most likely for the more mobile nutrients and mechanistic modelling can be used to select tree and crop species with superior rooting and physiological characteristics for interplantings to better manage below-ground competition.
Key wordsNitrogen phosphorus potassium rooting density root biomass
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