IMPROVING THE EFFECTIVENESS OF PR THROUGH COMBINING WITH ORGANIC MATERIALS AND MIXING WITH TSP IN TWO CALCAREOUS SOILS I.DIRECT EFFECTS

Abstract

A pot experiment was conducted to determine the role of organic materials (peat and sludge) applied with phosphate rock (PR) and partial acidulation of PR (through mixing with a water soluble P fertilizer (TSP) in different ratios 50:50 and 60:40 TSP: PR) on effectiveness of PR (Dry weight, P uptake, NaHCO3-P, and water soluble P). Corn "maize" (Zea mays L. var. Rabee) was used as a test crop in two soils, medium and fine textured soils. Effects of treatments on some soil properties like water soluble Ca, EC, and pH was studied too. Results showed that 60TSP +40PR treatment was superior in dry weight of corn and NaHCO3-P followed by 50TSP+50PR treatment with no significant differences, while PR treatment was superior in P concentration in plant and P uptake followed by PR +sludge treatment with no significant differences. The 50TSP+50PR treatment gave the highest values of water soluble P and the lowest values of water soluble Ca, EC, and pH. The main effect of texture was for the benefit of medium textured soil (Jadria) where the highest values for dry weight, P concentration in plant, P uptake, and water soluble P were recorded. The fine textured sol (Gaiara) gave the highest values in water soluble Ca, and EC. The effect of texture on NaHCO3 –P was not significant. Results affirm the possibility of adopting (50TSP+50PR) treatment as alternative for single application of TSP or PR, due to the non-significancy of the differences between 50TSP+50PR treatment and 60TSP +40PR treatment.