Agroforestry Systems

, Volume 8, Issue 3, pp 257–265 | Cite as

Modelling nutrient flux and interspecies root competition in agroforestry interplantings

  • Andrew R Gillespie


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 words

Nitrogen phosphorus potassium rooting density root biomass 


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. 1.
    Barber, SA (1984) Soil nutrient bioavailability; A mechanistic approach. New York, John Wiley and Sons.Google Scholar
  2. 2.
    Barber, SA, Cushman, JH (1981) Nitrogen up take model for agronomic crops. In: Iskandar, IK, ed, Modelling wastewater renovation-land treatment, pp. 383–409. New York, Wiley-Interscience.Google Scholar
  3. 3.
    Johnson KD (1981) Tall fescue (Festuca arundinacea Schreb) root relationships. Ph.D. diss. West Lafayette, IN, Purdue University.Google Scholar
  4. 4.
    Jonsson, K, Fidjeland, L, Maghembe, JA, Hogberg, P (1988) The vertical distribution of fine roots of five tree species and maize in Morogoro, Tanzania. Agroforestry Systems 6: 63–69.CrossRefGoogle Scholar
  5. 5.
    Mengel, DB, Barber, SA (1974) Development and distribution of the corn root system under field conditions. Agron J 66: 341–344.Google Scholar
  6. 6.
    Nair, NPK (1984) Soil productivity aspects of agroforestry. Nairobi Kenya, ICRAF.Google Scholar
  7. 7.
    Nye, PH, Tinker, PB (1977) Solute movement in the soil-root system. Oxford, Blackwell.Google Scholar
  8. 8.
    Olsen, SR, Kemper, WD (1968) Movement of nutrients to plant roots. Adv Agron 20: 91–151.Google Scholar
  9. 9.
    9.Romheld, V, Marschner, H (1984) Plant-induced pH changes in the rhizosphere of ‘Fe-efficient’ and ‘Fe-inefficient’ soybean and corn cultivars. J Plant Nutrition 7: 623–630.Google Scholar

Copyright information

© Kluwer Academic Publishers 1989

Authors and Affiliations

  • Andrew R Gillespie
    • 1
  1. 1.Forest Nutrition Cooperative, Department of ForestryNorth Carolina State UniversityRaleighUSA

Personalised recommendations