| dc.description.abstract | The deficiency of P and the shortened growing seasons due to climate change are
identified constraints in the production of commonly grown long maturing maize hybrid
(H614) in the acid soils of Molo County, Kenya. The current study therefore
investigated (i) the effect of soil amendments; lime (L), minjingu phosphate rock (MPR)
and manure (FYM) on soil available P and its uptake, phosphorus use efficiency (PUE)
and maize grain yield of long (H614) and short (H513) maturing maize hybrids and (ii)
the relative agronomic efficiency (RAE) of MPR. Field experiments were set up at the
Kenya Agricultural Research Institute, Molo during the long rain seasons of 2009 and
2010. A randomized complete block design with a 23 factorial arrangement was used
for the first objective. The factors, each at two levels, were L (0 and 3 t ha-1
), MPR (0
and 60 kg P ha-1
) and FYM (0 and 5 t ha-1
) giving a total of eight treatments; C
(control), L, MPR, FYM, L+MPR, L+FYM, FYM+MPR and L+FYM+MPR. The relative
agronomic efficiency (RAE) of MPR was determined in a parallel experiment laid out in
randomized complete block design with a split plot arrangement and replicated thrice.
Maize hybrid H513 and H614 were the test crops in both experiments and constituted
the main plots. The split plots were control (0 kg P ha-1
), triple super phosphate (60 kg
P ha-1
) and MPR (60 kg P ha-1
). Soil available P and its uptake, PUE, RAE and maize
yields were the parameters measured. The application of soil amendments increased
soil available P and its uptake, PUE and maize yields over the control for both maize
hybrids. Highest values of the measured parameters were recorded in the
L+FYM+MPR treatment and for maize hybrid H614. The two year mean values of
relative agronomic efficiency RAE (%) of MPR were 60 (H513) and 66.7 (H614), and
significantly higher for the maize hybrid H614. The combined application of soil
amendments could thus improve maize productivity and is recommended for the acid
soils of Malo County. The maize hybrid H513 though with lower yields, matured faster
than H614 and would thus come in handy as an adaptation strategy in the face of
climate change and variability. Moreover, it has a low P requirement and a short growth
cycle thus making it an ideal variety, economically, for smallholder farmers | en_US |
