الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
Four experiments were conducted under laboratory and greenhouse condition. The first experiment was carried out under laboratory condition to study the effect of individual application of ordinary super phosphate (OSP) at the three rates of 0, 30 Kg P ha-1 (50% of Recommended dose, RD OSP) and 60 kg P ha-1 (100% RD OSP) and various organic manures i.e. compost at (1% (10 Mg ha-1) , 2% (20Mg ha -1) Com), chicken manure at 0.5% (5Mg ha-1), 1% (10Mg ha-1) CM) and rabbit manure at (0.5% (5Mg ha-1), 1% (10Mg ha-1) RM) as solid and their extracts as well as combination with (50% RD OSP) and abovementioned organic manures as solid and their extracts on P availability in clayey and sandy soils, at different incubation periods i.e. (10, 30, 60, 90 and 120 days). The other three experiments were conducted under greenhouse condition. The recommended doses, RD of mineral fertilizers (NPK) were applied as the following rates: 25 kg N ha-1 (50% RD) and 50 kg N ha-1 (100%RD) as ammonium sulphate (20.5% N), 30 kg P ha-1 (50%RD) and 60 kg P fed-1 (100%RD) as ordinary super phosphate (6.5% P) and 12.5 kg K ha -1 (50%RD) and 25 kg K ha -1 (100%RD) as potassium sulphate (42.5% K).
The other three greenhouse experiments were carried out to study the effect of mineral fertilization (NPK) either solely or combined at the rates of 50% RD NPK with abovementioned various solid organic sources as soil addition and liquid organic sources as soil and foliar addition on plant growth and some macronutrients uptake by plant grown on the clayey and sandy soils.
The results of investigated experiments can be summarized as following:
• The treatment of (50% RD OSP+1%Com+1%CM) as solid and liquid forms and the (1% Com+0.5% CM+0.5% RM) treatment as liquid form were more beneficial effect on soil P- availability than the solely (100% RD OSP) treatment in the case of clayey soil, while the treatments of (2% Com) as individual solid addition and the (50% RD OSP+ 1% Com+ 1% CM) treatment as liquid phase showed more effective on soil P- availability than the (100% RD OSP) in the sandy soil.
• In the case of solid organic manures addition, the greatest value of the total K- uptake was found with the (50% RD NPK+1% Com + 0.5% CM+0.5% RM) treatment in the clayey soil and the (1% Com+0.5%CM+0.5%RM) treatment in the sandy soil comparing with the other treatments.
• In the case of liquid organic manures as foliar addition, the greatest values of the total P and K – uptake by plants were found with the (50% RD NPK+2% CM) treatment in the clayey soil and with the (50% RD NPK+1% Com+1% RM) treatment in the sandy one compared to the other tested treatments.
• In the case of liquid soil application, the highest values of the total N and Pــuptake were observed with the (1% Com+1% CM) treatment in the clayey soil, and the treatment of (2% Com) in the sandy one comparing with the other treatments.
It could be concluded that, the use of 50% of the recommended dose of phosphatic fertilizer (OSP) or mineral fertilizers (NPK) mixed with organic manures as solid and liquid forms may reduce the mineral fertilization (NPK) dose, production cost, and environmental contamination and soil salinization.