Abstract:
Combined use of organic amendments (OA) with mineral fertilizer is a feasible method of nutrient management to
deal with soil fertility decline, soil organic matter depletion, crop growth and yield reduction. To study the effect of
different nutrient management strategies on different soils, a greenhouse experiment was set-up in a complete
randomized design (CRD). Organic amendments, cattle manure-saw dust (CS) incubated for two months and bio-char
(BC) produced from saw dust. Soil samples were collected from fields in Wagolla (WG) and Peradeniya (PD). Site-specific fertilizer recommendation was developed for each soil. Shoot and root biomass of one month old maize (Zea
mays) was measured in OA+mineral fertilizer added soils, soil+fertilizer-only (SF) and soil-only (S) treatments. Each
soil was different in available plant nutrients and nutrient fixing ability. Shoot biomass ranged from 1.11 to
3.17g/plant and from 0.89 to 2.04g/plant in WG and PD soils, respectively. Root biomass varied from 1.08 to
1.99g/plant and from 0.81 to 2.13g/plant in WG and PD soils, respectively. Shoot and root biomasses were
significantly higher (P<0.05) when soil was mixed with fertilizer alone or OA + fertilizer compared to soil-only
treatment. The CS+SF treatment showed the highest shoot biomass in both soils and significantly high root biomass in
PD soil. In BC+SF treatment shoot and root biomass was reduced by 13% and 25% , respectively compared to SF.
Difference in nutrient management strategies and soil characteristics affected soil's capacity to support crop growth.
Plant growth support capacity of soil was enhanced by CS+SF combination.
