Agroforestry Systems

, Volume 35, Issue 1, pp 15–29 | Cite as

Using sap flow gauges to quantify water uptake by tree roots from beneath the crop rooting zone in agroforestry systems

  • S. B. Howard
  • C. K. Ong
  • C. R. Black
  • A. A. H. Khan
Article

Abstract

Grevillea (Grevillea robusta A. Cunn.; Proteaceae) is used in agroforestry in many areas of the highlands of East and Central Africa, and is reported to be mainly deep rooted, with few shallow roots and correspondingly low levels of competition with associated crops for water and nutrients. To examine the extent of below-ground complementarily in water use between grevillea and cowpea (Vigna unguiculata L.; Leguminosae), experiments were carried out at the International Centre for Research in Agroforestry (ICRAF) Field Centre at Machakos, Kenya. Sap flux was measured using heat balance gauges attached to the stems of young grevillea trees (10–18 months old), both before and after excavating the crop rooting zone (upper 60 cm of soil) around the stem base, in order to establish the capacity of the grevillea to extract water from below this zone. After excavation, the trees maintained sap fluxes of up to 85% of the unexcavated values, suggesting a high degree of below-ground complementarity.

Key words

below-ground complementarity Grevillea robusta heat balance Kenya tree-crop interactions 

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References

  1. Daniel JN, Ong CK and Kumar MS (1991) Growth and resource utilization of perennial pigeonpea (Cajanus cajan (L) Millsp.) at the tree-crop interface. Agrofor Syst 12: 83–98Google Scholar
  2. Dawson TE and Ehleringer JR (1991) Streamside trees that do not use stream water. Nature 350: 335–336CrossRefGoogle Scholar
  3. Green SR and Clothier BE (1995) Root water uptake by kiwifruit vines following partial wetting of the root zone. Plant and Soil 173: 317–328CrossRefGoogle Scholar
  4. Howard SB, Ong CK, Rao MR, Mathuva M and Black CR (1995) The partitioning of light and water inLeucaena/maize agroforestry systems. In: Sinoquet H and Cruz P (eds) The Ecophysiology of Tropical Intercropping, pp 123–135. INRA Editions, ParisGoogle Scholar
  5. Huxley PA (1983) Some characteristics of trees to be considered in agroforestry. In: Huxley PA (ed) Plant Research and Agroforestry, pp 3–12. ICRAF, NairobiGoogle Scholar
  6. Ishida T, Campbell GS and Calissendorf C (1991) Improved heat balance method for determining sap flow rate. Agric For Meteorol 56: 35–48CrossRefGoogle Scholar
  7. Jonsson K, Fidjeland L, Maghembe JA and Högberg P (1988) The vertical distribution of fine roots of five tree species and maize in Morogoro, Tanzania. Agrofor Syst 6: 63–69Google Scholar
  8. Khan AAH and Ong CK (1995) Correction of systematic errors in estimates of transpiration obtained using a constant temperature heat balance technique. Exp Agric 31: 461–472Google Scholar
  9. laycock DH and Wood RA (1963) Some observations of soil moisture use under tea in Nyasaland. II. The effect of shade trees. Trop Agric (Trinidad) 40: 42–48Google Scholar
  10. Mwihomeke ST (1993) A comparative study of the rooting depth ofGrevillea robusta interplanted with sugar-cane along contour strips. In: Harwood CE (ed)Grevillea robusta in Agroforestry Systems, pp 117–124. ICRAF, NairobiGoogle Scholar
  11. Ong CK and Khan AAH (1993) The direct measurements of water uptake by individual tree roots. Agrofor Today 5: 2–5Google Scholar
  12. Ong CK, Black CR, Marshall FM and Corlett JE (1996) Principles of resource capture and utilisation of light and water. In: Ong CK and Huxley P (eds) Tree-Crop Interactions in Agroforestry Systems, pp 73–158. CAB International, Wallingford, UKGoogle Scholar
  13. Ong CK, Corlett JE, Singh RP and Black CR (1991) Above and below-ground interactions in agroforestry systems. For Ecol Manage 45: 45–57CrossRefGoogle Scholar
  14. Spek LY and van Noordwijk M (1994) Proximal root diameters as predictors of total root system size for fractal branching models. II. Numerical model. Plant and Soil 164: 119–128Google Scholar
  15. van Roode M (1992) Agroforestry and the availability of soil water: a study on soil water in an agroforestry system in Kalalu, Kenya. MSc Thesis, University of Utrecht, The NetherlandsGoogle Scholar

Copyright information

© Kluwer Academic Publishers 1997

Authors and Affiliations

  • S. B. Howard
    • 1
    • 2
  • C. K. Ong
    • 1
  • C. R. Black
    • 2
  • A. A. H. Khan
    • 1
  1. 1.International Centre for Research in Agroforestry (ICRAF)NairobiKenya
  2. 2.Department of Physiology and Environmental Science, Sutton Bonington Campus University of NottinghamLoughboroughUK

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