Biological Nitrogen Fixation College of Tropical Agriculture and Human Resources (CTAHR) Biological Nitrogen Fixation UH Seal Unversity of Hawaii at Manoa
Project History
Training Resources
Inoculant Technology
Project Impact


Research objectives at NifTAL included development and delivery of effective BNF and soil management technologies for developing countries. Much or our research addressed the biological, environmental, and management constraints to enhanced BNF, as well as the methodological limitations that restrict our knowledge of the nitrogen-fixing process. Unique, targeted research on improving the production and delivery systems of high quality legume inoculants was also conducted. Our research results are published in US and international scientific journals, and compiled at Publications.

Research for More Efficient Inoculant Production.  NifTAL identified highly effective rhizobial strains for inoculants, inexpensive methodologies for producing inoculants, quality control, and inoculant application.  See the Inoculant Technology page for resource documents in this area.

Environmental Data Collection to Maximize Performance of Biological Nitrogen Fixation.  NifTAL's objectives included developing an environmental database to create a predictive model of inoculant performance, identification of environmental impacts on BNF, and development of crop management strategies to maximize BNF in tropical agro-ecosystems. Studies included standardized field trials to measure the performance and ecology of rhizobia in tropical soils. Other topics included legume crop development, yield and nitrogen fixation as affected by modes of nitrogen nutrition, environment and management. Results of these studies are incorporated into legume crop models through our collaborative linkages. Our research also supports the use of BNF for ecosystem restoration efforts.

Development of Methodologies for Monitoring Microorganisms. Improved methods were developed for monitoring the success of introduced rhizobia in the field and for quality control of inoculants. NifTAL developed low-cost serological methods appropriate for developing country conditions, appropriate enumeration methods, and computer software to assist quality control and research.

Genetic Technologies for Improvement of Rhizobium/Legume Symbiosis for Crops and Trees.  Modern and conventional biotechnological tools were used to select highly effective rhizobia, delineate their genetic relationships, identify environmental stress tolerance, and understand the mechanisms of inter-strain competition. Molecular characterization is used to improve the potential for genetic manipulation to maximize BNF.