Growth response of Grevillea robusta A. Cunn. seedlings to phosphorus fertilization in acid soils from Kenya
Date
1999Author
Mwendwa, KA
Karanja, NK
Zapata, F
Type
ArticleLanguage
enMetadata
Show full item recordAbstract
Three experiments were conducted to assess the response of
G. robusta
to phosphorus fertilization using acid soils showing
low P
levels from Eastern (Gituamba-Andosols) and
W
estern (Kakamega-Acrisols) Kenya. In the first experiment P
was
applied as Minjingu phosphate rock (MPR-13%P) at 0, 52 and 77 kg P
per ha into 5
kg of soil. In the second experiment 2
g
vesicular arbuscular mycorrhizae (VAM) soil + root inoculum per 5
kg soil was included in addition to the same MPR rates
using Kakamega soil only. In the third experiment, MPR and triple superphosphate (TSP) were added to 5
kg Kakamega soil
at a rate of 25.8
mg P
per kgsoil, and
32
P
isotope dilution techniques were used to assess P
uptake in the shoot harvested at
3 and 6 MA
T
(months after transplanting). Application of MPR to the Andosol reduced height and root collar diameter of
G.
r
obusta
significantly (p <
.05) as compared to the control. Significant increases (p
<
.05) in height and root collar diameter
where P
was added compared to control were recorded with the Acrisol. Soil interaction with P
fertilizer rates was highly
significant (p
<
.001) for both height and root collar diameter growth. The roots were not infected with
V
AM upon harvesting
at 12 months. At 3 MA
T
the percentage P
derived from the MPR and TSP
was 3% and 6% respectively. P
uptake decreased
significantly (p
<
.05) between 3 and 6 months. The results indicated that addition of Pfertilizer in the Acrisols was probably
required at the early stages of
G. robusta
growth but further research and particularly root studies are required to ascertain
the above observations
Citation
" BIOTECHNOLOGIE AGRONOMIE SOCIETE ET ENVIRONMENT 3 (1999): 57-64.Publisher
University of Nairobi, college of agriculture and veterinary sciences,
Subject
AcrisolsAndosols
phosphate rock
P update
P isitope dilution technique
triple super phosphate
arbuscular mycorrhiza
Grevillea robusta
seedlings
growth.