Partial substitution of mineral nitrogen fertilizer by bio-fertilizer on (Anethum graveolens L.) plant

摘要

A field experiment was conducted at the Experimental Farm of the Pharmaceutical Department, Agriculture college, Giza, Egypt to study the effect of partial substitution of mineral nitrogen fertilizer by biofertilizer and their effects on the growth, yield and chemical constituents of dill plant during the two successive seasons of 2007/2008 and 2008/2009. Because of the great importance of volatile oil, its composition was also investigated in this study. Five strains of bacteria (1- Azotobacter chroococcum, 2- Azospirillum lipoferum, 3- Bacillus polymyxa, 4- Bacillus megatherium and 5- Pseudomonas fluorescens) were mixed in equal parts and used as biofertilizer in this experiment. The biofertilizer treatment was applied alone or in combination with 1/3, 2/3 or full recommended dose of mineral nitrogen fertilizer. The results indicated that applying biofertilizer treatment alone or in combination with chemical N fertilizer increased the growth, yield and chemical constituents of dill plant compared to the untreated control. The highest values of vegetative growth, oil yield, chlorophyll content and NPK percentages were recorded by the treatment of bio-fertilizer plus two third of recommended dose of nitrogen fertilizer. The lowest values in this respect were obtained by control plants during two seasons. The GC analysis of volatile oil indicated that the main components were carvone, limonene and apiol. These components were affected by biofertilization and chemical N treatments. Partial substitution of mineral nitrogen fertilizer by bio-fertilizer was recommended to increase the yield as well as the quality of dill plant. By applying the treatment of bio-fertilizer plus two third of recommended dose of nitrogen fertilizer we can save the quantity of N chemical fertilizer used and obtain high quality product. The results of this study gave also the possibility of shifting toward clean agriculture.