5622
Eman Ali Abd El Rahman Ali
Studies On Some Factors Affecting The Solubility Of Rock Phosphate In Some Soils Of Egypt
Rock phosphate , Organic acids , Elemental sulfur , Ammonium thiosulfate , Oxalic acid , Phosphate Solubilizing Bacteria
The main objective of this research Evaluating the validity of direct application of rock phosphate types from its various sources in Egypt and determining the best sources to apply some stimulation agents to increase its efficiency and use it as fertilizer then apply of the best amendments on field to assess the suitability of these amendments to increase the productivity of soybean and maize crops The most important results obtained can be summarized in the following points: Experiment with organic acids, which aims to evaluate the efficiency of organic acids, where three concentrations of these acids were used (40, 50 and 60mmol/L) at different time periods (2, 4, 6 and 8 days) where the results indicated that oxalic acid and citric acid had the most significant effect and the highest amount of phosphorus extract (8000-4739mg/kg), respectively, when using the concentration (60 mmol/L) at 6 days and it was found that the best types of rock phosphate under study is Abu Tartour. Then the incubation experiment was carried out by mixing the different stimulation agents with rock phosphate (Abu Tartur) on two types of soils (sandy and clayey) and the experiment was carried out at different time periods (14,28,42,56 and 70 days). From the results we found that the ammonium thiosulfate recorded the highest mean significant increase in the amount of phosphorus extracted (60-56mg/kg) in clayey and sandy soils, respectively, as well as the highest decrease in acidity number 7.0 in the clayey soil compared to control (pH 7.9). Then the greenhouse experiment was conducted on the soybean (Glycine max) (legume plant) cultivar (Giza 111) and maize (Zea mays L.) hybrid cultivar TWC 324 three-way-cross (non legume plant) crops on both soils (sandy and clayey) using the selected and mixed treatments with rock phosphate and the highest increase in the fresh- dry weight, shoot and root and the plant length when adding and mixing ammonium thiosulfate and oxalic acid with rock phosphate, either separately or in combination, where the soybean plant in the sandy soil were ( 23.5, 23.3 and 18.6%) and for maize (19.4, 19.0 and 9.1%), respectively, similarly, trend in the clayey soil . Then the field experiment was conducted to apply the same previous treatments on the field scale and determine its efficiency in obtaining the highest of grains and straw yields for both soybean and maize crops on the sandy soil in Nubaria area where it was found that the treatment of (Rock phosphate+Oxalic acid+Ammonium thiosulfate) was the highest increase in both grain and straw yields, as well as in the biological yield, it was (113.5, 28.0 and 53.5%), (205.5, 168.8 and 186.1%) for soybeans and maize crops, respectively, compared to rock phosphate, while the treatment (Rock phosphate+Phosphate solubilizing bacteria) was recorded the least increase in all growth parameters of the two crops compared to phosphate rock only or SSP
2020
Ph.d
Cairo
Agriculture