Abstract:
In an integrated approach to cut-down on inorganic fertilizer use by smallholder farmers for agricultural production through the
use of biochar, a split-split plot experimental design with three replications was carried to determine the effect of biochar from
three different feedstock (corn cob, rice straw and cocoa pod husk) applied at two different rates of the feedstock (2.5 t ha-l and 5
t/ha) with three application rates of Nitrogen, Phosphorus and Potassium (N-P-K) as inorganic fertilizer (90-60-60, 45-30-30 and
0-0-0) on maize growth and yield as well as soil chemical properties. The main plots of the experimental design were allocated to
the biochar types while the Sub-plot was allocated to the biochar rates. The Sub-sub-plot went for the inorganic fertilizer rates.
The maize seeds were sown at spacing of 80 cm between rows and 40 cm between plants. Three seeds were sown per each stand
which was later thinned to two plants two weeks after planting. Urea, Triple superphosphate and Muriate of Potash were used as
the sources of inorganic nitrogen, phosphorus and potassium (N-P-K) respectively. The P and K were applied once two weeks
after planting while the N was split applied. One third of the application rate of nitrogen was applied two weeks after planting
and the remaining two thirds applied six weeks after planting. Soil samples were collected from 0-20 cm depth before planting
(one composite sample from the experimental site) and at harvest (from each treatment plot) to evaluate the effect of the different
amendments on different soil chemical properties notable N, P, K, CEC, and pH. The quantity of biochar application had
pronounced effects on maize grain yields where higher application rates (5 t/ha) showed superior performance to 2.5 t/ha.
