Immediate and Residual Availability of Phosphate Fertilizer as Influenced by Water Solubility and Granulation of Phosphate, Concurrent Nitrogen Application and Soil Reaction

An investigation was undertaken to study the immediate and residual availability of phosphate fertilizer as influenced by initial water solubility and granulation of phosphate, concurrent nitrogen application and soil reaction.Greenhouse experiments were conducted using oats as the indicator crop. Three soils were utilized in the experiments, one soil having a low pH and the others being calcareous in nature.The investigation was conducted in two separate parts. It seems evident that high water solubility is a desirable attribute for phosphate fertilizer whatever the soil or fertilizer management practice.Especially is high water solubility important with calcareous soil.These observations would undoubtedly be magnified under conditions of optimum placement of fertilizer in bands. Advisor: R. A. Olso