Abstract:
Soil phosphorus (P) loss from agricultural systems in Sri Lanka limits food
production. Phosphorous is mainly removed from the soil with the harvested portion
of the crop. Triple Super Phosphate (TSP) is one of the main inorganics of P for
cropping systems. Plant-available forms of phosphorus in topsoil are required for
plant growth and productivity. Although the Eppawala Rock Phosphate (EPR) is a
natural P source found in Sri Lanka, P in it is less readily available to crops than that
in TSP. This study focuses on increasing the plant availability of phosphorus from
EPR using three different biofertilizers. Three different biofertilizers were prepared
using soil microbes from Pine Forests (PFB), Lower Montane Forest (LMB), and
bamboo bushes (BBF). Control was only with the topsoil collected from the farm, and
the other treatment was the same potting media without biofertilizer. Gliricidia
leaves, cow dung, brown sugar, and natural water were used for culturing microbes.
Potting media containing a mixture of compost (30%), biochar (5%), EPR (5%)
powder, and farm soil (15 kg) was used for the experiment. Five treatments, together
with the control, were arranged in a randomized complete block design (RCBD).
Winged Bean (Xanthosoma sagittifolium) was planted as the indicator crop. After a
two-month period, a significant increase in the above-ground biomass of Winged
Bean was observed in PFB and LMB. A significant increase in no of pods has resulted
from PFB and BFB in Winged Bean. Thus, it was evident that PFB is effective in
increasing the growth and productivity of winged Beans (Xanthosoma sagittifolium).
