| dc.description.abstract | Fertilizer use in Kenya and Africa has been on a declining trend, because of high maize
production-input prices relative to output price. With increased prices of fertilizers there
is a need for maize production guidelines on altemative fertility management
technologies for fanners. Manure is the most effective and affordable material for
supplying plant nutrients (Siderus and Muchena, 1977) and its efficient management may
be a cornerstone for sustainable agriculture. Field experiments were conducted at Manor
House Agriculture Centre, Kitale, Kenya to determine the influence of farmyard manure
(FYM) alone or in combination with nitrogen (N) fertilizer on soil fertility, maize growth
and yield under field conditions. The experiments were laid out in a randomized complete
block design with four replications over two seasons during the long rains (April -
September 1998) and st;hl rains (October 1998 - March 1999). Treatments consisted of
non-fertilized (control), .5 ton FYM/ha + 45 kg N Iha, 5 ton FYM/ha + 30 kg N/ha, 7.5 v"
ton FYM/ha + 15 kg N/ha, composted FYM ®OnJha dry weight) and recommended
inorganic fertilizers (60 kg Iha and 60 kg P20s/ha). The inorganic phosphate fertilizer
was applied as diammonium phosphate (DAP). Inorganic nitrogen ( ) fertilizer was
applied as calcium ammonium nitrate (CAN). The FYM was hand-broadcasted and
incorporated into the experimental plots one week before planting in both seasons. Soil
pH and nutrient levels (% C, % N, P, K, Ca, Mg, Mn, Na), maize growth, grain yield and
yield components were measured. The results revealed that the residual effect of
inorganic fertilizers on soil nutrients was not superior to that of FYM treatments. The
effect of the treatments on the yield components was translated into the final grain yield.
The average maize grain yield was 10.8 and 4.3 ton/ha in first and second seasons,
respectively. FYM and N interactions increased yields up to 53% and 41% over the
control during the first and second crop seasons, respectively. FYM alone increased yield
by 45% and 8 % over the control during the first and second crop seasons, respectively.
Approximately equal yields were obtained in maize fertilized with 7.5 tons FYM/ha + 15
kg N/ha, 5 ton FYM/ha + 30 kg N/ha, 60 kg P20slha + 60 kg Iha, 1G tons FYM/ha,
whereas low yields were observed with 2.5 ton FYM/ha + 45 kg N Iha and the control.
Overall maize yield was 60% lower in season II compared to season 1. This work has
revealed the usefulness of using FYM as a basal fertilizer that can substitute for inorganic
basal fertilizers in maize growing with equally good results. The slow-nutrient (nitrogen)
release from organic manure appears to supply the plant demands throughout the growing
period. It can, therefore, be concluded that application of FYM improves crop yields, but
may not have much beneficial effect on the fertility status of the soil. The results further
reveal that use of recommended inorganic fertilizers does not lead to an increase in yield
comparable to the FYM treatments.
An economic study is needed to determine the cost especially labor of FYM use and to
help identify types of farming systems within which FYM is likely to be beneficial to the
farmer in increasing and sustaining soil fertility. | en |
