EFFECTIVENESS OF SOIL AMENDMENTS IN RESTORING THE CHEMICAL PROPERTIES OF SOILS SUBJECTED TO DIFFERENT INTENSITIES OF EROSION IN NSUKKA, SOUTH EASTERN NIGERIA

The effectiveness of soil amendments in restoring the chemical properties of soils subjected to different intensities of erosion in S.E Nigeria was studied in the field. The experiment was arranged as a split-plot in a randomized complete block design. The main plot treatments were the four erosion levels viz, E-1 (slightly eroded with average annual soil loss of 3.28 t/ha/yr), E-2 (slightly eroded with average annual soil loss of 3.96 t/ha/yr), E-3 (eroded with average annual soil loss of 46 t/ha/yr) and E-4 (severely eroded, with average annual soil loss of 147 t/ha/yr). The sub-plot treatments were: control (no amendment), inorganic fertilizer, NPK (F), poultry manure (PM), rice shavings mixed with poultry manure (RS+PM), rice shavings mixed with fertilizer (RS+F) and rice shavings alone (RS). Poultry manure (PM) alone and RS + PM significantly increased the soil organic carbon, total nitrogen, exchangeable bases and cation exchange capacity. Generally, organic residues proved superior to inorganic fertilizers in restoring the chemical properties of the eroded soils. However, PM restored the chemical properties of the eroded (E-2) and severely eroded (E-3) soils to the level obtained in the very slightly eroded soil (E-1).