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Soil physical
and chemical properties under continuous maize cultivation
as influenced by hedgerow trees species on an alfisol in
south western Nigeria
D. J. Oyedele1, O. O.
Awotoye2* and S. E. Popoola3
1Department
of Soil Science, Obafemi Awolowo University, Ile-Ife,
Nigeria.
2Institute
of Ecology and Environmental Studies, Obafemi Awolowo
University, Ile-Ife, Nigeria.
*Corresponding author. E-mail:
segunawotoye@yahoo.co.uk.
Accepted 22 June, 2009 |
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In the sub-humid tropical Africa, the pressure of
diminishing land resources resulting from the rapidly
increasing population has made the traditional fallow
systems used for the replenishing soil fertility impossible.
Alley cropping has been suggested as an alternative to bush
fallowing. This study evaluated the effects of 20 years of
different species of hedgerow crops on the physical and
chemical properties of soil. Soil physical and chemical
properties were studied under Pterocarpus santalinoides,
Gliricidia sepium, Enterolobium cyclocarpum
and Leucaena and leucocephala intercropped
with maize (Zea mays L.) at a 20 years old Leventis
Foundation Farm, at Ilesa in the south western part of
Nigeria. Soil bulk density was significantly reduced under
the hedgerow species from a maximum of 1.52 g cm-3
under control to 1.33 g cm-3 under Pterocarpus
and Enterolobium hedgerows. While the soil cone
penetrometer resistance index followed a similar trend, the
soil field capacity was lowest under Pterocarpus and
highest under Leucaena hedgerows. Soil porosity
increased significantly (p < 0.05) from 0.38 under control
to a maximum of 0.47 under Pterocarpus, while the
hydraulic conductivity at a suction of -0.5 cm was
significantly highest Gliricidia hedgerow. Soil pH
and other chemical properties were consistently highest
under Leucaena and consistently Gliricidia
hedgerow. Overall among the screened hedgerow species, G.
sepium showed the best promise in terms of improvement
in both soil physical and chemical properties.
Key words:
Hedgerow, alley cropping, hydraulic conductivity,
Pterocarpus, Gliricidia, Leucaena, Enterolobium, cone
penetrometer resistance, field capacity. |
