The pot experiments were performed at the Faculty of Agriculture, Minufiya University, Shibin El-Kom to investigate the effect of different sources and rates, of P, K and organic manure on corn plants grown in both alluvial and calcareous soils. Two surface soil samples (0 – 30 cm) were collected from two locations. A) alluvial soil from experimental farm of the Faculty of Agriculture, Minufiya University, Shibin El-Kom. B) calcareous soil from Nubaria farm, Behera Governorate. Each polyethylene pot (15 cm diameter) was filled with 2 kg soils and planted with five grains of corn plant (Zea mays L.). After 14 days from planting the plants thinned to three plants per pot. The pots were irrigated to keep soil moisture at approximately 60% of the water holding capacity. The organic manure was added at 0, 1 and 2%. P was added at (0, 15 and 30 ppm, P2O5) of superphosphate and Triplephosphate. The organic manure and phosphatic fertilizers were added before planting. Potassium was added at 0, 24 and 48 ppm K2O of potassium sulphate and potassium chloride.
After 45 days from planting the plants were harvested and dried at 70°C, weighted, ground and digested for chemical analysis.
The application of FYM at rates of 1 and 2% to the both alluvial and calcareous soils caused a significant increase in dry matter yield of corn plants. The values of dry matter yield in alluvial soil, were higher than those obtained in the calcareous soil. The additions of FYM to both soils increased the N, P and K uptake by corn plants. The application of FYM increased the availability of P and K in used soils. The application of phosphatic fertilizers increased the dry matter yield of corn plants grown in both. The dry matter yield of corn plants with triplephospate application was higher than those with superphosphate in alluvial soil, while the reverse was reverse was true in calcareous one. The N, P and K uptake by corn plants were obviously higher on alluvial soil than those on calcareous one with P application. The application of phosphate fertilizers increased available P and slightly increased available K in used soils. Available P and K in alluvial soil were higher than those in calcareous one. Application of potassium sulphate was more effective in increasing dry matter yield of corn plants than potassium chloride in both soils. The absolute values of N, P and K uptake by corn plants by K2SO4 application were higher than those treated with KCl-fertilizers. Application of potassium fertilizers increased the available K in both used soils and slightly decreased availability P in alluvial soil but there is no effect in calcareous soil.