Abstract
Present study conducted during 2008-09 addresses the acquisition of nutrients from soil by tobacco (Nicotiana tabacum L.) plants with specific emphasis on the genotype and soil type with reference to structural and functional characteristics of roots that influence the availability and uptake of P and N. Objective is to explore the impact of tobacco genotypes VT-1158 and Siri in vertisols whereas 16/108, and Kanchan in alfisols on the activity of beneficial microorganisms such as Azotobacter, Azospirillum and Pseudomonas along with native microflora of the rhizosphere. After 45 DAT, the bacterial population was highest in number and it ranged from 7.02 to 10.90 in tobacco rhizosphere of vertisols and alfisols, while fungi were lowest in number which ranged from 3.92 × 103 to 5.30 × 103 cfu/g soil in the rhizosphere soil of vertisols var VT-1158 and Siri respectively. At 90 DAT microbial population declined in vertisols and alfisols of all the varieties. Inoculation of Azospirillum and Pseudomonas along with application of RDF resulted in maximum viable cell number of 5.89 × 106 cfu/g and 5.90 × 106 cfu/g soil in case of vertisols rhizoshpere of var VT-1158, while 5.95 × 106 cfu/ g and 6.47 × 106 cfu/g soil in the rhizosphere of alfisols tobacco respectively after 45 DAT. Inoculation of bacteria either as monoculture or mixed biofertilizer resulted in almost 10-30 times increase in microbial population of the inoculated bacteria; however, their population decreased after 90 DAT. Mixed biofertilizer (Azotobacter, Azospirillum and Pseudomonas) had a prolonged effect on plant parameters tested and showed a higher nutrient (N and P) content.
Publisher
Indian Council of Agricultural Research, Directorate of Knowledge Management in Agriculture
Subject
Agronomy and Crop Science
Reference14 articles.
1. AOAC. 1950. Official Methods of Analysis, 7th edn, pp 12–4. Washington DC. USDA.
2. Alizade O and Ordookhani K. 2011. Use of N2 fixing bacteria Azotobacter, Azospirillum in optimizing of using nitrogen in sustainable wheat cropping. Advances in Environmental Biology 5(7): 1 572–74.
3. Bais H P, Weir T L, Perry L G, Gilroy S and Vivanco J M. 2006. The role of root exudates in rhizosphere interactions with plants and other organisms. Annual Review of Plant Biology 57: 233–66.
4. Brimecombe M J, De Leij F A A M and Lynch J M. 2007. Rhizodeposition and microbial populations. (In) The Rhizosphere Biochemistry and Organic Susbstances at the Soil-plant Interface, pp 73–109. Pinton R, Varanini Z, Nannipieri P (Eds). CRC Press, Boca Raton, Florida.
5. Bucher M. 2007. Functional biology of plant phosphate uptake at root and mycorrhiza interfaces. New Phytology 173: 11–26