Statistical analysis
The study was conducted using a three
factor nested design, where the fertilizer practices
were nested in districts while the soil depths were
nested in the fertilizer practices. The data were
subjected to analysis of variance using a general
linear model. A two- sample paired t-test was used
to compare the nutrient differences between the
surface soil (0–20 cm) and the subsoil (21–40 cm).
Statistical significance was tested at the 0.05 level
and high significance at the 0.01 level.