Effective factors on biological nitrogen fixation

Abstract

Although relationships among plant, biological N 2 fixation, and response to soil and environmental conditions have received considerable coverage in the scientific literature, a comprehensive summary and interpretation of these interactions with specific emphasis are lacking. Fluctuations in pH, nutrient availability, temperature, and water status, among other factors, greatly influence the growth, survival, and metabolic activity of nitrogen fixation bacteria. The subsequent inhibition of nitrogenase would result in O 2 accumulation in the infected zones, inducing the decrease in nodule permeability. Poor nodulation of legumes in arid soils is likely due to decreases in population levels of rhizobia during the dry season. Fixation, therefore, also tends to decrease with legume age, mainly because of the concomitant increase in soil N. Calcium deficiency, with or without the confounding influence of low pH also affects attachment of rhizobia to root hairs. Rhizobia may have different tolerances to soil acidity factors than the host plant. Relatively, high-root temperature has also been shown to influence infection, N 2-fixation ability, and legume growth. Also, root nodulation by the bacteria can be dependent on the formation of mycorrhiza.

Nodulation, Nutrient Uptake and Yield of Common Bean Inoculated with Rhizobia and Trichoderma in an Acid Soil

“…The ability of legumes to form nodules has been attributed to many soil and biological factors that include levels of mineralizable N, levels of available P, soil reaction in the form of pH, type and vigour of legume, Rhizobia populations and their effectiveness in infecting and nodulating the host (Mohammadi, Shohrabi, Gholamreza, Khalesro, & Majidi, 2012). Vol.…”

“…Our results show a 4 fold increase in the number of nodules per plant and corroborate with earlier findings that inoculating common bean with Rhizobia can cause a significant increase in the number of nodules per plant (Otieno et al, 1997). It must be noted, however, that inoculation with Rhizobia may not always result in enhanced nodulation due to many other factors; these include the presence of many but ineffective Rhizobia strains; the ensuing competition between the introduced and the indigenous strains; poor quality of the inoculum and unfavourable soil conditions (Mcloughlin & Dunican, 1985;Montealegre & Graham, 1996;Mohammadi et al, 2012). This study shows that there is added value with respect to number of nodules per plant as well as their effectiveness when Rhizobia and Trichoderma are co-inoculated compared to when they are applied singly.…”

Green Bean Yield and Path Analysis in Cowpea Landraces

“…The fact that bean yield in the first experiment was higher than (10 landraces) or equal to (two landraces) in the second experiment suggests that climatic conditions were more favorable to cowpea growth in the first experiment (Table 1). Belane and Dakora (2010) found that genotypes with the highest N 2 fixation rates also had the largest biomass and the highest grain yield, indicating that several abiotic factors can affect symbiotic nitrogen fixation (MOHAMMADI et al, 2012). In addition, N 2 fixation depends on genotype and year of evaluation (BELANE; DAKORA, 2010).…”

The bacterial diversity investigation in oil palm plantation using terminal restriction length polymorphism

“…In fact, it was only found in Bangka, which had more sandy texture compared to other sampling sites. Other bacteria present in this cluster are Streptomyces, which produces antibiotics; along with Clostridium and Pseudomonas, which are beneficial bacteria used as biofertilizer due to their phosphate solubilizing and nitrogen fixing activity [24].…”