Abstract:

Soil health is an indispensible component of an environment that reflects the capacity of soil
to provide ideal conditions for normal plant growth and support to ecosystem services.
However, the potential of soils to sustainably support ecosystem service and optimize crop
yields is threatened by land degradation. A field experiment was conducted at Ngctta ZARDI,
Lira city with the aim of evaluating soil amendment techniques using organic and inorganic
fertilizers for increased yield of upland rice in northern Uganda. Specifically, the study
determined the effects of varying levels of solid waste compost, farm yard manure and NPK
fertilizer on soil chemical properties and yield, and examined the effect of organic soil
amendments on the concentration of heavy metals in soil and rice grains. The experiment was
laid out in a Spli-plot design with three replications. The treatments used included; solid
waste compost (SWC) at 5, 10 and 15 tons/ha, farmyard manure (FYM) at 5, 10 and 15
tons/ha and NPK fertilizer (NPK) at 100, 200 and 300 kg/ha and control. Data on yield
components, growth parameters, grains and soil samples were subjected one way-way
ANOVA test to analyze differences between the means of dependent variables. The results
indicated that the highest yield of 4.1 tons/ha was obtained from NPK fertilizer applied at 300
kg/ha, followed by SWC 10 and FYM 15 that gave the yields of 2.9 tons/ha and 2.8 tons/ha,
respectively, compared to control at 1.5 tons/ha grain yield. The highest concentration of
heavy metal (Cadmium) was obtained from treatments of SWC 15 and FYM 15 at 1.77 and
1.13 ppm. respectively, compared to control at 0.10 ppm. Therefore, the study established
that application of fertilizer packages, significantly increased soil organic matter, nutrient
contents and grain yields. The application of SWC and FYM increased concentration of Cd in
soils and grains after soil organic amendments.