Journal Browser

► Journal Browser

Special Issue Information

Dear Colleagues,

Legumes are a major component of all agrarian systems on Earth. They are particularly attractive to low input systems of agriculture because they take inert nitrogen from the air and transform it into proteins, in a process that leaves no carbon footprint. The bacteria associated with legumes, and which produce the enzymatic mechanisms that reduce atmospheric di-nitrogen (N₂) to ammonia, are collectively termed rhizobia or root-nodulating bacteria.

The legume symbiosis with rhizobia has been acknowledged as fundamental to sustainable agriculture because this intimate relationship between soil bacteria and flowering plants can alleviate the need to provide manufactured nitrogen (N) into farming systems. We now understand that our changing climate has resulted substantially from the burning of fossil fuels, such as in the manufacture of Fertiliser N, and thus any anthropomorphic activity (such as legume cultivation) that can limit consumption of fossil fuels must be embraced.

This has brought a renewed focus to the science of biological nitrogen fixation (BNF). Combined with the discovery of new rhizobia such as the burkholderia, our increased understanding of gene function, and the continued domestication of legumes, BNF has re-emerged as an essential knowledge base for all productive agricultural systems.

We invite contributions to this Special Edition, including new research results, reviews and opinion pieces that cover any of these broad aspects of BNF.

Prof. Dr. John Howieson
Guest Editor

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Agronomy is an international peer-reviewed open access monthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2600 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

Rhizobia and nodule bacteria
Legumes
nitrogen fixation
Agriculture
Inoculation
agro-ecosystems
symbiosis

Published Papers (2 papers)

Download All Papers

Research

229 KiB

Open AccessArticle

N₂ Fixation of Common and Hairy Vetches when Intercropped into Switchgrass

by Amanda J. Ashworth, Fred L. Allen, Kara S. Warwick, Patrick D. Keyser, Gary E. Bates, Don D. Tyler, Paris L. Lambdin and Dan H. Pote

Agronomy 2017, 7(2), 39; https://doi.org/10.3390/agronomy7020039 - 08 Jun 2017

Cited by 5 | Viewed by 4013

Abstract

Interest in sustainable alternatives to synthetic nitrogen (N) for switchgrass (Panicum virgatum L.) forage and bioenergy production, such as biological N₂ fixation (BNF) via legume-intercropping, continues to increase. The objectives were to: (i) test physical and chemical scarification techniques (10 total) for common vetch (Vicia sativa L.); (ii) assess whether switchgrass yield is increased by BNF under optimum seed dormancy suppression methods; and (iii) determine BNF rates of common and hairy vetch (Vicia villosa L.) via the N-difference method. Results indicate that chemical scarification (sulfuric acid) and mechanical pretreatment (0.7 kg of pressure for one minute) improve common vetch germination by 60% and 50%, respectively, relative to controls. Under optimum scarification methods, BNF was 59.3 and 43.3 kg·N·ha⁻¹ when seeded at 7 kg pure live seed ha⁻¹ for common and hairy vetch, respectively. However, at this seeding rate, switchgrass yields were not affected by BNF (p > 0.05). Based on BNF rates and plant density estimates, seeding rates of 8 and 10 kg pure live seed (PLS) ha⁻¹ for common and hairy vetch, respectively, would be required to obtain plant densities sufficient for BNF at the current recommended rate of 67 kg·N·ha⁻¹ for switchgrass biomass production in the Southeastern U.S. Full article

(This article belongs to the Special Issue Rhizobium-legume Symbiosis Effects on Plants)

245 KiB

Open AccessArticle

Improvement of Faba Bean Yield Using Rhizobium/Agrobacterium Inoculant in Low-Fertility Sandy Soil

by Sameh H. Youseif, Fayrouz H. Abd El-Megeed and Saleh A. Saleh

Agronomy 2017, 7(1), 2; https://doi.org/10.3390/agronomy7010002 - 01 Jan 2017

Cited by 45 | Viewed by 10185

Abstract

Soil fertility is one of the major limiting factors for crop’s productivity in Egypt and the world in general. Biological nitrogen fixation (BNF) has a great importance as a non-polluting and a cost-effective way to improve soil fertility through supplying N to different agricultural systems. Faba bean (Vicia faba L.) is one of the most efficient nitrogen-fixing legumes that can meet all of their N needs through BNF. Therefore, understanding the impact of rhizobial inoculation and contrasting soil rhizobia on nodulation and N₂ fixation in faba bean is crucial to optimize the crop yield, particularly under low fertility soil conditions. This study investigated the symbiotic effectiveness of 17 Rhizobium/Agrobacterium strains previously isolated from different Egyptian governorates in improving the nodulation and N₂ fixation in faba bean cv. Giza 843 under controlled greenhouse conditions. Five strains that had a high nitrogen-fixing capacity under greenhouse conditions were subsequently tested in field trials as faba bean inoculants at Ismaillia Governorate in northeast Egypt in comparison with the chemical N-fertilization treatment (96 kg N·ha⁻¹). A starter N-dose (48 kg N·ha⁻¹) was applied in combination with different Rhizobium inoculants. The field experiments were established at sites without a background of inoculation under low fertility sandy soil conditions over two successive winter growing seasons, 2012/2013 and 2013/2014. Under greenhouse conditions, inoculated plants produced significantly higher nodules dry weight, plant biomass, and shoot N-uptake than non-inoculated ones. In the first season (2012/2013), inoculation of field-grown faba bean showed significant improvements in seed yield (3.73–4.36 ton·ha⁻¹) and seed N-yield (138–153 Kg N·ha⁻¹), which were higher than the uninoculated control (48 kg N·ha⁻¹) that produced 2.97 Kg·ha⁻¹ and 95 kg N·ha⁻¹, respectively. Similarly, in the second season (2013/2014), inoculation significantly improved seed yield (3.16–4.68 ton·ha⁻¹) and seed N-yield (98–155 Kg N·ha⁻¹) relative to the uninoculated control (48 kg N·ha⁻¹), which recorded 2.58 Kg·ha⁻¹ and 80 kg N·ha⁻¹, respectively. Interestingly, faba bean inoculated with strain Rlv NGB-FR 126 showed significant increments in seed yield (35%–48%) and seed N-yield (34%–49%) compared to the inorganic N fertilizers treatment (96 kg N·ha⁻¹) over the two cropping seasons, respectively. These results indicate that inoculation of faba bean with effective rhizobial strains can reduce the need for inorganic N fertilization to achieve higher crop yield under low fertility soil conditions. Full article

(This article belongs to the Special Issue Rhizobium-legume Symbiosis Effects on Plants)

Journal Menu

Journal Browser

Rhizobium-legume Symbiosis Effects on Plants

Share This Special Issue

Special Issue Editor

Special Issue Information

Keywords

Published Papers (2 papers)

Research

Further Information

Guidelines

MDPI Initiatives

Follow MDPI