Assessment of the Effect of Glycine, Oxalic Acid andNitrogen-Phosphorus-Potassium (NPK) Fertilizer asNutrient Supplement Using Phosphate and OxalicAcid as Indices

This study evaluated the release profiles of phosphate and oxalic acid in soils treated with oxalicacid a low molecular weight organic acid and glycine an amino acid compared with NPK fertilizermonitored over a period of21 days. The soil treated with oxalic acid and glycine released higherphosphate and oxalic acid than that treated with NPK fertilizer. The soil treated with oxalic acidreleased higher phosphate than that which was treated with glycine while higher oxalic acid wasobserved in the soil treated with glycine rather than for that treated with oxalic acid. Significanteffects were observed between the treatment and the length of time for phosphate release (P<0.05)while for the release of oxalic acid, there was no significant effect between the treatment (P>0.05)but with increase in length of time (P<0.05). This demonstrates the efficient ability of oxalic acidand glycine as substitutes for phosphate fertilizers.