الفهرس | Only 14 pages are availabe for public view |
Abstract The current work is interested in studying the nature of some selected soil amendment enhancers in the laboratory in terms of some mineralogical initial characters, i.e., their X-ray diffraction as well as their response to the metal bioleaching due to the inoculation with P or K- solubilizing bacteria and/or their co-culture. Furthermore, studying their effect on P & K uptake of maize plants and the soil available P & K in a greenhouse experiment. In addition, a field experiment was laid out to evaluate their effect on maize growth, maize ear yield, maize seed yield. The obtained results could be summarized as in the following: 1- Laboratory work: 1.1. Bioleaching of K from feldspar, bentonite and biochar: Any of Bacillus circulans, Serratica mercescenes, Pseudomonas fluorescence and their co-culture mixture was able to act as bioleaching agent to liberate K from any of feldspar, bentonite and biochar. Their Co-culture mixture recorded the highest available bioleached K amount from biochar followed by those scored by Ps. fluorescence, B. circulans and Serratica mercescenes in respective order compared to control without inoculation. Also, the bioleached available K amount from biochar was much higher than that bioleached from feldspar. 1.2. Bioleaching of P from rock phosphate and biochar: - Both Bacillus polymyxa and Bacillus megaterrium and their co-culture and/or their co-culture ware able to release P from rock phosphate and biochar. - Inoculation with co-culture bacterial mixture achieved the highest amount of available bioleached P from rock phosphate. This available bioleached P from rock phosphate was quite higher than that leached by biochar. 2- Greenhouse work: - Using biochar alone at 3 tons fed-1 gave the highest mean value for maize plant dry weight, plant height, P & K plant uptake and soil available, P & K. - Using rock phosphate alone recorded the highest mean values for maize plant dry weight and maize plant height, P plant uptake and soil available P. - Using feldspar alone gave the highest mean value K plant uptake and the highest mean value of soil available K. - The interaction between any of bentonite and biochar each applied at a rate of 3 tons fed-1gave the highest maize plant dry weight. - The interaction between any of rock phosphate and biochar each applied at a rate of 3 tons fed-1gave the highest maize plant height, P plant uptake and soil available P. - The interaction between any of bentonite and biochar each applied at a rate of 3 tons fed-1gave the highest maize K plant uptake. - The interaction between any of feldspar and biochar each applied at a rate of 3 tons fed-1gave the highest maize soil available K. 3- Field work: - Using biochar alone at 3 tons fed-1 combined with bacterial inoculation gave the highest mean value for maize plant dry weight, plant height, P & K plant uptake, soil available, P & K, maize ear yield, and maize seed yield compared to those recorded by same treatment without bacterial inoculation. - Using rock phosphate recorded the highest mean values of for maize plant dry weight, plant height, plant P uptake; soil available P, maize ear yield and maize seed yield compared to those obtained by the un-inoculated treatments. - Using feldspar along with bacteria inoculation recorded the highest mean value of maize plant K uptake compared to those recorded by same treatment without bacterial inoculation. - Using bentonite along with bacteria inoculation recorded the highest mean value of soil available K compared to those recorded by same treatment without bacterial inoculation. - . The interaction between any of rock phosphate along with bacterial inoculation and biochar each applied at a rate of 3 tons fed-1gave the highest maize dry weight, plant height, plant P uptake, soil available P, maize ear yield and maize seed yield. - The interaction between any of feldspar along with bacterial inoculation and biochar each applied at a rate of 3 tons fed-1gave the highest maize plant K uptake and soil available K. |