Azza R. Ahmed; M.A. Bayoumi; H.M. Khalil and M.S. Awaad( 2011). Role Of Bio And Organic Fertilization On Sustaining Nitrogen Requirements For Rice Production J. Soil Sci. and Agric. Eng., Mansoura Univ., Vol.2 (1): 43 - 57
Abstract: A field experiment was performed on a clay soil at Bahtim Agriculture Research Station during season 2009 to evaluate the effective role of bio (blue green algae, BGA), organic manure (farmyard, FYM) in combination with two N-mineral sources, urea (46 % N) and urea-formaldehyde (40 % N) at different rates (0, 30, 45 and 75 kg N/fed) on rice growth parameters, yield and N-use efficiency as well as some soil properties. The obtained results revealed that the greatest values of the studied growth parameters, i.e., plant height, number of tillers/m2 as well as 1000 grain weight, straw and grain yields (biological yield) were achieved at the highest N-rate of urea-formaldehyde combined with BGA. Nitrogen use efficiency was affected by the applied different treatments; however, the total N-uptake was higher with urea-formaldehyde at the rate of 75 N kg /fed, as compared to urea, combined with either BGA or FYM. This was true, since urea-formaldehyde is characterized by N-slow release during the growth stages of rice crop. Also, total N-uptake was more pronounced with the applied recommended dose of urea-formaldehyde (90 kg N/fed) as compared to urea. Moreover, application of the combined treatment of urea-formaldehyde + FYM resulted in the greatest soil organic matter content, total nitrogen and available nitrogen as compared to the other applied treatments, contrary the reverse trend was true for soil pH. Concerning the water stable aggregates, soil aggregate size distribution was more affected by the applied different treatments. However, soil aggregation exhibited an improvement towards the application of urea-formaldehyde or urea combined with FYM. So, the application of natural bio and organic manures, i.e., blue green algae or local organic farmyard manure with urea formaldehyde are considered the best option not only for maximizing rice grain yield, its quality and reducing the harmful effects of using nitrogenous chemical fertilizers, but also for sustaining soil fertility status. Moreover, the application of bio-organic manures leads to rationalize use of N-mineral fertilizer for the growing crop, which is surplus point for sustainable agriculture system, as well as represents a solving for the problems of chemical residues in the export market commodities.
Keywords: (Urea, urea-formaldehyde, blue green algae, organic manures, rice. )
