Abstract:
ABSTRACT
Soil fertility decline remains the major biophysical constraint to low crop
productivity on farmlands. Even though inorganic fertilizers play significant
role in increasing crop production, they are not a sustainable solution in
maintaining high crop yields as it gradually deteriorates soil physico-chemical
properties which subsequently reduce crop yield. Both pot and field experiments
were conducted to determine the effect of combined application of compost and
biochar on soil pH, total nitrogen, available phosphorus, nutrient use and
efficiency, total organic carbon, bulk density, field capacity, hydraulic
conductivity as well as the yield of cabbage (test crop). A completely
randomised design and randomised complete block design were used for pot
and field experiments respectively with 3 cabbage varieties for the pot and 2
cabbage varieties for the field. Total microbial count in log/cfu was determined
using the total plate count. Five treatments were evaluated, sole biochar (B),
sole compost (C), compost + biochar (CB), NPK fertilizer (NPK) and control
(no application). There was no significant difference among the treatments in
all the soil parameters measured for pot experiment except the pH for NPK
which was lower (5.83) compared to B (6.58), C (6.47) and CB (6.51). In the
field experiment, B and CB increased total organic carbon (1.21% and 1.54%
respectively). The C and CB increased the crop yield, soil total N and soil
available P concentrations. Application B also increased soil microbial
population. A combination of compost and biochar can therefore be used as a
soil amendment to increase yield and improve soil physico-chemical properties
under field conditions.
