Browsing by Author "WAKWAYYA AMSALE"

Filter results by typing the first few letters
Now showing 1 - 2 of 2
  • No Thumbnail Available
    Item
    ISOLATION, CHARACTERIZATION AND EVALUATION OF SYMBIOTIC EFFICIENCY OF INDIGENOUS RHIZOBIA FROM TRAP CULTURES IN BORICHA AND LOKKA ABAYA DISTRICT, SIDAMA REGION, ETHIOPIA
    (Hawassa University, 2024-11) WAKWAYYA AMSALE
    The excessive use of chemical fertilizers to boost crop yields has significant environmental drawbacks, including soil degradation, water contamination, and greenhouse gas emissions. Additionally, these fertilizers are often costly, making them inaccessible to many smallholder farmers. Leguminous crops play a crucial role in sustainable agriculture, contributing to soil fertility and crop productivity through their symbiotic relationship with rhizobia, which fix atmospheric nitrogen. Identifying and utilizing effective indigenous rhizobia is vital for improving legume yields, as these microorganisms are well-adapted to local environmental conditions, offering a cost-effective and eco-friendly alternative to chemical fertilizers. This study was aimed at isolation and characterization of indigenous rhizobia from soils in Boricha and Lokka Abaya districts in Sidama, Ethiopia, using groundnut and chickpea plants as a trapping host. Fourteen rhizobial isolates were successfully obtained after presumptive and authentication tests. All isolates tolerated alkaline conditions at pH 8, with 10 showing acid tolerance at pH 4. Most isolates grew at pH 5, except NiG2, NiG8, and NiC12, while nine tolerated pH 10. None of the isolates grew at pH 11. Notably, NiG8 was the only isolate capable of solubilizing tri-calcium phosphate. In metal resistance assessments, most isolates demonstrated growth on YEMA medium with aluminum, copper, and zinc, with 10 showing tolerance. Eight isolates exhibited resistance to manganese, and six to cobalt, while only NiG5, NiG8, and NiC12 tolerated mercury. Host range tests revealed significant host specificity and variability; Eight isolates nodulated soya bean effectively, six nodulated the common bean variety "Tafach," seven the "Nasir" variety, and five were effective on fava bean. No isolates nodulated lentil. Further analysis of symbiotic effectiveness showed significant differences (p<0.05) in nodule number, nodule dry weight, and shoot dry weight in fava bean, soya bean, groundnut, Tafach and Nasir. Most isolates exhibited high symbiotic effectiveness, often surpassing the nitrogen control and commercial inoculants. Isolates NiC4 and NiC7 demonstrated high effectiveness on chickpea, with values of 129% and 99.1%, respectively. On groundnut, NiG3 and NiG8 reached 103.4% effectiveness, with NiG6 also achieving 120% on the "Tafach" variety. For variety Nasir NiG6 showed 118.9% effectiveness, and NiG10 recorded 95.9%. These findings highlight the diversity and potentials of indigenous rhizobia to enhance legume productivity and soil fertility.
  • No Thumbnail Available
    Item
    ISOLATION, CHARACTERIZATION AND EVALUATION OF SYMBIOTIC EFFICIENCY OF INDIGENOUS RHIZOBIA FROM TRAP CULTURES IN BORICHA AND LOKKA ABAYA DISTRICT, SIDAMA REGION, ETHIOPIA
    (Hawassa University, 2024-11) WAKWAYYA AMSALE
    The excessive use of chemical fertilizers to boost crop yields has significant environmental drawbacks, including soil degradation, water contamination, and greenhouse gas emissions. Additionally, these fertilizers are often costly, making them inaccessible to many smallholder farmers. Leguminous crops play a crucial role in sustainable agriculture, contributing to soil fertility and crop productivity through their symbiotic relationship with rhizobia, which fix atmospheric nitrogen. Identifying and utilizing effective indigenous rhizobia is vital for improving legume yields, as these microorganisms are well-adapted to local environmental conditions, offering a cost-effective and eco-friendly alternative to chemical fertilizers. This study was aimed at isolation and characterization of indigenous rhizobia from soils in Boricha and Lokka Abaya districts in Sidama, Ethiopia, using groundnut and chickpea plants as a trapping host. Fourteen rhizobial isolates were successfully obtained after presumptive and authentication tests. All isolates tolerated alkaline conditions at pH 8, with 10 showing acid tolerance at pH 4. Most isolates grew at pH 5, except NiG2, NiG8, and NiC12, while nine tolerated pH 10. None of the isolates grew at pH 11. Notably, NiG8 was the only isolate capable of solubilizing tri-calcium phosphate. In metal resistance assessments, most isolates demonstrated growth on YEMA medium with aluminum, copper, and zinc, with 10 showing tolerance. Eight isolates exhibited resistance to manganese, and six to cobalt, while only NiG5, NiG8, and NiC12 tolerated mercury. Host range tests revealed significant host specificity and variability; Eight isolates nodulated soya bean effectively, six nodulated the common bean variety "Tafach," seven the "Nasir" variety, and five were effective on fava bean. No isolates nodulated lentil. Further analysis of symbiotic effectiveness showed significant differences (p<0.05) in nodule number, nodule dry weight, and shoot dry weight in fava bean, soya bean, groundnut, Tafach and Nasir. Most isolates exhibited high symbiotic effectiveness, often surpassing the nitrogen control and commercial inoculants. Isolates NiC4 and NiC7 demonstrated high effectiveness on chickpea, with values of 129% and 99.1%, respectively. On groundnut, NiG3 and NiG8 reached 103.4% effectiveness, with NiG6 also achieving 120% on the "Tafach" variety. For variety Nasir NiG6 showed 118.9% effectiveness, and NiG10 recorded 95.9%. These findings highlight the diversity and potentials of indigenous rhizobia to enhance legume productivity and soil fertility.