الفهرس 
Introduction
Increasing phosphorus efficiency under egyptian conditionsOnly 14 pages are availabe for public view
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Abstract
The aim of the present study : was to increase and compare the efficiency use of P fertilizers as superphosphate (Sph.) and rock phosphate (Rph.) under new reclaimed soil of Egypt (sandy & calcareous) by application some combinations of different amendments such as biofertilizers (Bio.), sludge (Slu.) and sulfur (S) . The obtained results of the present study could be summarized as follows: *As an indicator to increase efficiency of phosphatic fertilizers some parameters of soybean plants were measured such as : dry weights of roots , straw , seeds and whole plant <U+2013> N , P , K concentrations (%) , contents and uptake in these organs and by whole plants . *application the amendments of sludge, biofertilizers (phosphate solubilizing bacteria and mycorrhiza) and elemental sulfur with phospatic fertilizers such as super and rock phosphate into studied soil increased previous soybean parameters to the level of significant. *Several parameters were used to study the residual effect of amendments on P efficiency using corn as a plant indicator. The used parameters on corn plants were: dry weight <U+2013> N, P, K concentration (%) and uptake <U+2013> P efficiency use (PEU, %). *The results confirmed that the residual effect of adding the amendments with super and rock phosphate was significant for all parameters except for P % in both seasons. However the treatment of adding (Slu.+S.+Bio.) with (Sph.) recorded the highest values . Some values of this treatment on corn plants grown after soybean at both seasons were around: 33.64 g/pot for dry matter 0.03 and 0.04% for P concentration <U+2013> 4.5 % for (PEU) *The high values of residual effect under calcareous soil were attributed to the high removal of nutrients by previous grown crop (soybean) in sandy soil. *The present investigation studied the effect of applying amendments with phosphatic fertilizers (super and rock phosphate) on phosphorus forms (available, total inorganic and organic) and fixation capacity before sowing and after harvesting of soybean as well as after corn harvesting as a residual effect. The important results can be summarized in following: *The statistical analysis indicated that adding the different amendments of sludge, sulfur and biofertilizer with (Sph.) or (Rph.) into calcareous soil increased P forms (available , total inorganic and organic) to the level of significance before seeds sowing and after soybean harvesting as well as after corn harvesting in comparison with adding the amendments to sandy soil. * Applying amendments with phosphatic fertilizers as Sph., or Rph. into both sandy and calcareous soil increased available P from soybean sowing until harvesting in both season. * Finally, the present study under pot experiments conditions and for 4 months is recommended by addition the amendments of sludge , biofertilizers (phosphate solubilizing bacteria and mycorrhiza) and elemental sulfur with phosphatic fertilizers such as super and rock phosphate into newly reclaimed soils of Egypt as sandy and calcareous soils. * Also, more studies must be done under field conditions with different crops to emphasize the present recommendation which was under pots conditions and for 4 months.