scholarly journals Determination of Biological Nitrogen Fixation Induced N2O Emission from Arable Soil by Using a Closed Chamber Technique

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Ambreen Shah
Keyword(s):  
Nitrogen Fixation ◽  
Total Nitrogen ◽  
Biological Nitrogen Fixation ◽  
Bare Soil ◽  
Total Carbon ◽  
Organic Carbon Content ◽  
Closed Chamber ◽  
Mineral N ◽  
Biological Nitrogen ◽  
Chamber Technique

Intensive use of mineral N fertilizers and organic amendments has resulted in higher N2O emissions. A growing worldwide concern for these problems has motivated researchers, environmentalists, and policy makers to find alternatives to overcome such losses. Biological nitrogen fixation is one of many natural biological approaches to minimize the use of fertilizers and to possibly reduce N2O emissions. A greenhouse study was performed by growing inoculated and noninoculated soybean seeds (Glycine max (L.) Merr.) in PVC columns. The objective was to measure the contribution ofBradyrhizobium Japonicumand mineral-N fertilizer to promoting N2O emission. A closed chamber technique was used for gas sampling. N2O measurements were carried out shortly after nodulation.Bradyrhizobium Jopanicuminduced N2O cumulative (121.8 μg kg−1) fluxes of inoculated seeds was significantly (α= 0.05) higher than those of mineral N fertilized treatment (NIS) and the control (bare soil). Total nitrogen content of the roots and seeds was not affected by inoculation. Total carbon ( 42.1  ±  0.1%), total nitrogen (3.1  ±  0.1%), and crude protein (19.9  ±   0.7%) contents of leaves of the inoculated seeds were significantly higher than those of noninoculated seed treatments. N2O fluxes significantly increased with high dissolved organic carbon content (70.77  ±  3.99  mg L−1) at R3 and at R8 stages whenNO3-(39.60  ±  0.94 mg L−1) concentrations were high.

scholarly journals Evaluation of Cowpea (Vigna unguiculata L.walp) Genotypes for Biological Nitrogen Fixation in Maize-cowpea Crop Rotation

2019 ◽  
Vol 8 (1) ◽  
pp. 82
Author(s):  
Simunji Simunji ◽  
Kalaluka L. Munyinda ◽  
Obed I. Lungu ◽  
Alice M. Mweetwa ◽  
Elijah Phiri
Keyword(s):  
Nitrogen Fixation ◽  
Total Nitrogen ◽  
Biological Nitrogen Fixation ◽  
Block Design ◽  
Maize Yield ◽  
Isotopic Analysis ◽  
Plant Parts ◽  
Randomized Complete Block Design ◽  
15N Urea ◽  
Biological Nitrogen

Nitrogen is a major plant nutrient which is most limiting in the soil due to soil losses of mineral nitrogen (N) form. To ensure availability of nitrogen in the soil, the study was conducted to screen four cowpea genotypes for Biological Nitrogen Fixation (BNF) and their contribution to maize yield in maize- cowpea rotation. The cowpea genotypes used were mutants LT11-3-3-12 (LT) and BB14-16-2-2 (BB) and their parental varieties Lutembwe (LTPRT) and Bubebe (BBPRT) respectively. Trials were established at two sites (Chisamba and Batoka) of different soil types. The Randomized Complete Block Design (RCBD) with three replications was used. Labelled 15N urea was applied at 20kgNha-1 on the four cowpea genotypes during 2015/16 growing season. Cowpea plant parts were dried and milled for 15N isotopic analysis. The data collected included Nitrogen content and atom % 15N excess in the fixing cowpea genotypes and non-nitrogen fixing pearl millet to determine total nitrogen derived from the atmosphere (TNdfa) and total nitrogen (TN) in plant parts which were further used to compute Biological Nitrogen Fixation (BNF). The results showed that BNF by cowpea genotypes at Chisamba was 63.9 kg ha-1 and was significantly (P<0.001) more than BNF of 6.6 kgha-1 at Batoka. The LT mutant fixed significantly (P<0.001) higher nitrogen of 86.1 kgha-1 and 16.5kg ha-1 at Chisamba and Batoka respectively than other genotypes. However, both BB and LT mutants significantly fixed more nitrogen than their parents and have demonstrated to increase maize grain yields up-to 12 tha-1 in the maize – cowpea rotation.

scholarly journals Evaluation of the Symbiotic Efficiency of Rhizobium Strains Applied to Bituminaria bituminosa (L.) Stirton

2020 ◽  
pp. 45-55
Author(s):  
Omar Zennouhi ◽  
Abderrazak Rfaki ◽  
Mohamed El Mderssa ◽  
Jamal Ibijbijen ◽  
Laila Nassiri
Keyword(s):  
Nitrogen Fixation ◽  
Total Nitrogen ◽  
Biological Nitrogen Fixation ◽  
Dry Weight ◽  
Pastoral Systems ◽  
Plant Resources ◽  
Symbiotic Efficiency ◽  
Rhizobium Strains ◽  
Bituminaria Bituminosa ◽  
Biological Nitrogen

Aims: The study aimed to evaluate the effect of inoculation by different rhizobacteria on Bituminaria bituminosa plants grown under greenhouse conditions. Study Design: An experimental study. Place and Duration of Study: The study was carried out at the Department of Biology (Environment and valorization of microbial and plant resources Unit), Faculty of Sciences, Moulay Ismail University-Meknes, from November 2019 to February 2020. Methodology: Eleven species and/or isolates belonging to Rhizobium genus are used to inoculate B. bituminosa plants; similarly, fresh and dry crushed nodules previously collected from B. bituminosa shrubs are tested. The bacterial inoculation effects are evaluated through the estimation of inoculated plants’ fresh and dry shoots weight, root dry weight, total nitrogen, nodules number and fresh weight in comparison to non-inoculated plants. The infectivity and efficiency of the bacteria and the biological nitrogen fixation are also evaluated. Results: The results enable us to select the infective strains on the basis of their positive effect on growth and total nitrogen, in order to produce inoculum for B. bituminosa. Efficiency and biological nitrogen fixation are also very high compared to the control, especially with the B.b1 strain isolated from Bituminaria bituminosa and identified as Rhizobium tibeticum. The fresh nodules crushing is also very efficient. as inoculant. Conclusion: The use of symbiotic complex as Rhizobium tibeticum – Bituminaria bituminosa or an inoculum produced from fresh nodules are an eco-friendly alternative for the design of sylvo-pastoral systems ensuring increased soil fertility, fodder productivity and sustainable agroforestry.

scholarly journals Biological Nitrogen Fixation by Local and Improved Genotypes of Cowpea in Burkina Faso (West Africa): Total Nitrogen Accumulated can be used for Quick Estimation

2018 ◽  
Vol 2018 ◽  
pp. 1-8
Author(s):  
Boubié Vincent Bado ◽  
Michel Sedogo ◽  
François Lompo ◽  
Sanoussi Manzo Maman Laminou
Keyword(s):  
Nitrogen Fixation ◽  
Burkina Faso ◽  
Total Nitrogen ◽  
Biological Nitrogen Fixation ◽  
Polynomial Regression ◽  
Cropping Systems ◽  
Isotopic Dilution ◽  
Potential Contribution ◽  
Total N ◽  
Biological Nitrogen

Biological nitrogen fixation (BNF) by legumes is an indicator of their potential contribution to recycling nitrogen in cropping systems. Many techniques exist for the quantitative measurement of legume BNF. The isotopic dilution (ID) methods are the most accurate but are too expensive, time-consuming and require technical expertise. There is a gap between the simple but less accurate Total Nitrogen Difference (TND) method and the Isotopic Dilution (ID) methods. By measuring the BNF of 11 cowpea (Vigna unguiculata) genotypes, this study aimed to develop a simple model as an improved tool for the quick estimation of BNF. Total N accumulated by traditional genotypes from Burkina Faso varied from 23 to 41 kg ha−1. Approximately 40 to 65% of this was nitrogen derived from the atmosphere (Ndfa) when the TND method was used (Ndfa-TND), while the ID method indicated that 29 to 37% of N accumulated was derived from the atmosphere (Ndfa-ID). The TND method overestimated the BNF of high N-yielding genotypes but underestimated the BNF of low N-yielding genotypes (N-accumulated below 31 kg N ha−1). The relationship between N-accumulated and Ndfa-ID was described by a polynomial regression: Yi = 0.0127 Xi2 - 0.5354 Xi + 17.44, where Yi and Xi represent Ndfa-ID and N-accumulated, respectively (P<0.05, R2 =0.92). The model was validated and could be used for quick estimation of BNF directly from the N accumulated.

scholarly journals Functional analysis of multiple nifB genes of Paenibacillus strains in synthesis of Mo-, Fe- and V-nitrogenases

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Qin Li ◽  
Haowei Zhang ◽  
Liqun Zhang ◽  
Sanfeng Chen
Keyword(s):  
Functional Analysis ◽  
Nitrogen Fixation ◽  
Gene Cluster ◽  
Biological Nitrogen Fixation ◽  
Deletion Analysis ◽  
Phylogeny Analysis ◽  
Biological Nitrogen

Abstract Background Biological nitrogen fixation is catalyzed by Mo-, V- and Fe-nitrogenases that are encoded by nif, vnf and anf genes, respectively. NifB is the key protein in synthesis of the cofactors of all nitrogenases. Most diazotrophic Paenibacillus strains have only one nifB gene located in a compact nif gene cluster (nifBHDKENX(orf1)hesAnifV). But some Paenibacillus strains have multiple nifB genes and their functions are not known. Results A total of 138 nifB genes are found in the 116 diazotrophic Paenibacillus strains. Phylogeny analysis shows that these nifB genes fall into 4 classes: nifBI class including the genes (named as nifB1 genes) that are the first gene within the compact nif gene cluster, nifBII class including the genes (named as nifB2 genes) that are adjacent to anf or vnf genes, nifBIII class whose members are designated as nifB3 genes and nifBIV class whose members are named as nifB4 genes are scattered on genomes. Functional analysis by complementation of the ∆nifB mutant of P. polymyxa which has only one nifB gene has shown that both nifB1 and nifB2 are active in synthesis of Mo-nitrogenase, while nifB3 and nifB4 genes are not. Deletion analysis also has revealed that nifB1 of Paenibacillus sabinae T27 is involved in synthesis of Mo-nitrogenase, while nifB3 and nifB4 genes are not. Complementation of the P. polymyxa ∆nifBHDK mutant with the four reconstituted operons: nifB1anfHDGK, nifB2anfHDGK, nifB1vnfHDGK and nifB2vnfHDGK, has shown both that nifB1 and nifB2 were able to support synthesis of Fe- or V-nitrogenases. Transcriptional results obtained in the original Paenibacillus strains are consistent with the complementation results. Conclusions The multiple nifB genes of the diazotrophic Paenibacillus strains are divided into 4 classes. The nifB1 located in a compact nif gene cluster (nifBHDKENX(orf1)hesAnifV) and the nifB2 genes being adjacent to nif or anf or vnf genes are active in synthesis of Mo-, Fe and V-nitrogenases, but nifB3 and nifB4 are not. The reconstituted anf system comprising 8 genes (nifBanfHDGK and nifXhesAnifV) and vnf system comprising 10 genes (nifBvnfHDGKEN and nifXhesAnifV) support synthesis of Fe-nitrogenase and V-nitrogenase in Paenibacillus background, respectively.

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