Influence of line-planted trees and phosphorus application on water

  • M O Gunga
  • M.W K Mburu
  • J O Nyabundi
  • B Jama


Planting of trees in rows is common on farms in western Kenya where phosphorus deficiency is also a major constraint to maize production. The influence of soil P status and simultaneous agroforestry systems on water us have, however, not been reported in the region. Effects of line-planted Grevillea robusta (upperstorey trees), Calliandra calothyrsus and Senna spectabilis (both managed as hedges) and P on water use efficiency were investigated in maize. The experiment was laid out as a split-plot with tree species forming main plots while 250 kg P/ha and no P formed sub-plots. Seasonal evapotranspiration was greater under Grevillea by 40.8 mm (5.2%) in the Long Rains (LR) and by 49.3 mm (10.2%) in the Short Rains (SR). Phosphorus significantly increased seasonal evapotranspiration (ET) by 1.7% in the LR and 2.4% in the SR. Maize water use efficiency was higher with P (6.9 kg/ha/mm in the LR and 9.5 kg/ha/mm in the SR) than without P (0.8 kg/ha mm in the LR and 2.1 kg/ha/mm in the SR) The results revealed enormous potential for increasing maize WUE in these soils by overcoming P deficiency. Combining Grevillea trees with P enhanced use of seasonally available water.

How to Cite
Gunga, M., Mburu, M., Nyabundi, J., & Jama, B. (2008). Influence of line-planted trees and phosphorus application on water. East African Agricultural and Forestry Journal, 69(1&2). Retrieved from

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