Laila K.M. Ali, Samira E. Mahrous and H. M. Ramadan( 2009). Effect of organic and inorganic conditioners on P-release from rock phosphate and its impact on wheat planEgypt. J. Agric. Res., 87 (1), 2009
Abstract: The current work aims to evaluate the effect of organic materials application such as compost (rice straw), Humic acids(HA), Fulvic acids(FA) and agricultural sulfur(S), to rock phosphate (RP) on the availability of P and some macronutrients in the calcareous soil of AI-Galaa location, west Nubaria, cultivated with wheat during winter season 2006/2007. The obtained results showed the positive effect of applied humic and fulvic acids to RP inoculated with bacteria to P-re!ease from RP and gave the highest values of H2O-P, NaHOC3-P, NaOH-P, EDTA-P and occluded-P fractions by increasing the incubation time up till 21 days. Also, a gradual increase in the availability index (AI) was obtained. Application of organic materials results in improving the soil characteristics under study as it exhibited a gradual decrease or increase in the values of EC, pH and O.M. Moreover, the application of (HA+RP+B (bacteria)) increased the available N,P and K by 84, 87 and 39% more than the untreated rock phosphate. Concerning nutrient concentrations in wheat plant, data showed a high response to either the applied individual or combined treatments however, greater values were strictly associated with triple treatments under study. N, P and K% of both shoot and grains were affected by the following treatments and couid be arranged as follows: MF> HA+RP+B > FA+RP+B > S+RP+B for nitrogen while for P and K : the arrangements would be HA+RP+B > FA+RP+B > S+RP+B > MF. Significant increase exists in the values of wheat grain and straw yield (Kg/Fed.) , weight of 1000 grains and the quality parameter i.e crude protein and amino acids as well as N, P and K, due to application all treatments especially the combined treatments. This could be attributed to mineral enrichment, active organic compounds and bio substances which have the ability to chelate nutrients as available strategic storehouse and in turn reflected positively on development of crop yield and its components. This emphases the importance of organic materials to minimize consuming chemical fertilizers and to avoid environmental pollution hazards. Economical examination was carried out by calculating the benefit to cost ratio B/C parameter
Keywords: (Fractionation of phosphorus, rock phosphate, calcareous soil, wheat plant)
