Nitrogen Fixation

Technologies for Getting to Zero Emissions by 2060

Question: How fast are technologies to address climate change developing, particularly with regard to nitrogen fixation?

GenerallyEclectic looked at Canada's Greenhouse Gas emissions and found that in 2012, the agriculture sector contributed about 7.8 percent of Canada's emissions. These emissions came from a variety of sources, including enteric fermentation, manure and particularly soils. Viable soils are an essential component of the production of food and other agicultural products.

Nitrogen fixation has the potential to enhance soils without the need for nitrogen fertilizers. It could replace emissions related to the production, distribution and the spreading of nitrogen fertilizers, while eliminating all the harmful side effects of nitrogen usage.

To answer the question on how fast nitrogen fixation technologies are developing, GenerallyEclectic looked at articles in Science Daily on nitrogen fixation for the previous eighteen months, which at the time of writing was December 1, 2018 to May 31, 2020. Titles, summaries and links to the relevant articles are provided, so you can make your own judgments.

The summaries presented here are limited to Science Daily findings, which are in turn determined by Science Daily's methodology, which is outlined at About Science Daily. To the extent that Science Daily undoubtedly missed some technological developments, this summary under-reports developments.

Findings

1. How to boost plant biomass: Biologists uncover molecular link between nutrient availability, growth Findings have implications for increasing plant nitrogen use efficiency, reducing reliance on fertilizers10 May 2020: Plant scientists have long known that crop yield is proportional to the dose of nitrogen fertilizer, but the increased use of fertilizers is costly and harmful to the environment. Until now, the underlying mechanisms by which plants adjust their growth according to the nitrogen dose has been unknown...In a new study ..., plant genomic scientists ... discovered the missing piece in the molecular link between a plant's perception of the nitrogen dose in its environment and the dose-responsive changes in its biomass.
2. Reducing reliance on nitrogen fertilizers with biological nitrogen fixation25 Mar 2020: "A variety of nitrogen fixing bacteria are common in the rhizosphere of most plants. However, such plant growth promoting bacteria (PGPB) have seen only limited use as inoculants in agriculture."... Stacey and his team were most surprised to find that they did not see a significant impact on phytohormone production that correlated tightly with the ability of PGPB to enhance plant growth. This suggests that PGPB impact plant metabolism to a greater extent than previously realized, pointing perhaps to more complex explanations for how these bacteria impact plant growth.
3. Microbes play important role in soil's nitrogen cycle: But different microbes have distinct roles to play, and environmental factors influence activity.10 Mar 2020: "Soil microbes catalyze most of the transformations of soil nitrogen into plant-usable forms. Diverse microbes use different processes -- and sometimes work together. Knowing the various styles of soil microbes, and linking microbes to specific soil processes, can be important knowledge for farmers."
4. Some domesticated plants ignore beneficial soil microbes: Domestication yielded bigger crops often at the expense of plant microbiomes9 Mar 2020: A review by biologists finds that plant domestication has often had a negative effect on plant microbiomes, making domesticated plants more dependent on fertilizer and other soil amendments than their wild relatives. To make crops more productive and sustainable, the authors recommend reintroduction of genes from the wild relatives of commercial crops that restore domesticated plants' ability to interact with beneficial soil microbes.
5. Nitrogen-fixing trees help tropical forests grow faster and store more carbon: Planting fixers could benefit reforestation and climate mitigation plans12 Feb 2020: But new research ... shows that the ability of tropical forests to lock up carbon depends upon a group of trees that possess a unique talent -- the ability to fix nitrogen from the atmosphere. The study modeled how the mix of tree species growing in a tropical forest following a disturbance, such as clearcutting, can affect the forest's ability to sequester carbon. The team found that the presence of trees that fix nitrogen could double the amount of carbon a forest stores in its first 30 years of regrowth. At maturity, forests with nitrogen fixation took up 10% more carbon than forests without.
6. Plants manipulate their soil environment to assure a steady supply of nutrients28 Jan 2020: Dissolved carbon in soil can quench plants' ability to communicate with soil microbes, allowing plants to fine-tune their relationships with symbionts. Experiments show how synthetic biology tools can help understand environmental controls on agricultural productivity.
7. Nitrogen-fixing genes could help grow more food using fewer resources14 Jan 2020: Scientists have transferred a collection of genes into plant-colonizing bacteria that let them draw nitrogen from the air and turn it into ammonia, a natural fertilizer. The work could help farmers around the world use less human-made fertilizers to grow important food crops like wheat, corn, and soybeans.
8. Recrutement of a lateral root developmental pathway into root nodule formation of legumes25 Nov 2019: Peas and other legumes develop spherical or cylindrical structures -- called nodules -- in their roots to establish a mutually beneficial relationship with bacteria that convert atmospheric nitrogen into a useable nutrient for the legume plant. Root nodule symbiosis enables legumes to grow under nitrogen-limiting conditions where most of non-leguminous plants cannot survive. Researchers in Japan now have a better understanding of how the symbiotic relationship evolved.
9. Coated seeds may enable agriculture on marginal lands: A specialized silk covering could protect seeds from salinity while also providing fertilizer-generating microbes24 Nov 2019: Providing seeds with a protective coating that also supplies essential nutrients to the germinating plant could make it possible to grow crops in otherwise unproductive soils, according to new research...A team of engineers has coated seeds with silk that has been treated with a kind of bacteria that naturally produce a nitrogen fertilizer, to help the germinating plants develop. Tests have shown that these seeds can grow successfully in soils that are too salty to allow untreated seeds to develop normally. The researchers hope this process, which can be applied inexpensively and without the need for specialized equipment, could open up areas of land to farming that are now considered unsuitable for agriculture.
10. Nature's backup plan for converting nitrogen into plant nutrients10 Nov 2019: Researchers have found that nature has developed a backup method for converting atmospheric nitrogen into the nutrient form critical to plant growth and soil fertility. The researchers report that the process known as nitrogen fixation can be carried out by the metal vanadium in ecosystems where the primary catalyst molybdenum is scarce. The study suggests that nature's capacity to restore ecosystems in the wake of human-made disturbances or fertilize agricultural land is more resilient than previously thought.
11. New evidence that bacteria drive biodiversity in the Cape Floral Region29 Oct 2019: South African botanists have found evidence that the largest Cape geophyte genus, Oxalis, has developed a unique association with the bacterial genus Bacillus, that help it to fix nitrogen from the air and to perform extraordinary feats of germination. Furthermore, they demonstrate that the Bacillus bacteria are so integrated into this symbiotic relationship that they are even inherited from mother plant to seed. This is the first report of such a system of vertical inheritance of endophyte bacteria for geophytes.
12. Nodulation connected to higher resistance against powdery mildew in legumes6 Oct 2019: Scientists have long known that nodulation is important to plant health. Nodulation occurs when nodules, which form on the roots of plants (primarily legumes), form a symbiotic relationship with nitrogen-fixing bacteria that deliver nutrients to the plant. This process is a key part of sustainable agriculture and makes legumes an important source of protein for much of the world. However, recent research shows that nodulation might positively impact the plant's microbiome in other ways.
13. How nitrogen-fixing bacteria sense iron16 Sep 2019: New research reveals how nitrogen-fixing bacteria sense iron - an essential but deadly micronutrient. The findings are an important piece in the puzzle of how life deals with iron, a nutrient it cannot do without but one it must also avoid having in excess.
14. Scientists successfully inoculate, grow crops in salt-damaged soil: High-salinity land now unable to sustain plant life could once again be used21 Aug 2019: Researchers may have found a way to reverse falling crop yields caused by increasingly salty farmlands throughout the world. Scientists have used bacteria found in the roots of salt-tolerant plants to successfully inoculate alfalfa plants against overly salty soil.
15. New signaling component important for plant symbiosis31 Jul 2019: A proteomics-based protein-protein interaction study has led to the discovery of proteins that interact with a legume receptor that mediates signal transduction from the plasma membrane to the nucleus. This shows how symbiotic signals from symbiotic bacteria are transmitted upon perception, ultimately leading to their accommodation within the host plant.
16. 'Right' cover-crop mix good for both Chesapeake and bottom lines28 Apr 2019: Planting and growing a strategic mix of cover crops not only reduces the loss of nitrogen from farm fields, protecting water quality in the Chesapeake Bay, but the practice also contributes nitrogen to subsequent cash crops, improving yields, according to researchers.
17. Scientists develop methods to validate gene regulation networks: Findings reveal how plants respond to key nutrient in fertilizer4 Apr 2019: A team of biologists and computer scientists has mapped out a network of interactions for how plant genes coordinate their response to nitrogen, a crucial nutrient and the main component of fertilizer. The work ... offers a potential framework and more efficient methods that can be used to investigate a wide-range of vital pathways in any organism.
18. Natural selection favors cheaters: Research focused on interaction between nitrogen-fixing bacteria and their hosts18 Mar 2019: Natural selection predicts that mutualisms -- interactions between members of different species that benefit both parties -- should fall apart. Individuals that gain from the cooperation of others but do not reciprocate (so-called cheaters) should arise and destabilize mutualisms. Yet to date, surprisingly little evidence of such cheating or destabilization exists. A team of biologists has now found strong evidence of this cheating.
19. New nitrogen source in Arctic10 Mar 2019: Scientists have revealed that the partnership between an alga and bacteria is making the essential element nitrogen newly available in the Arctic Ocean. The microbial process of 'nitrogen fixation' converts the element into a form that organisms can use, and was discovered recently in the frigid polar waters. This shift may be a result of climate change and could affect global chemical cycles.
20. Living together: How legume roots accommodate two distinct microbial partners27 Feb 2019: Researchers have revealed a key piece in the complex genetic systems that control how legume roots form close associations (symbioses) with microbial partners that help supply nutrients to the plant. They discovered a gene in the model legume, Lotus japonicus, that is crucial for enabling both nitrogen-fixing rhizobia bacteria and mycorrhizal fungi to colonize the roots.
21. The paper mulberry coevolved with soil microbes to humanity's benefit25 Feb 2019: The paper mulberry evolved its uniquely fibrous inner bark around 31 million years ago, long before the woody tree was first used for bookmaking during China's Tang dynasty. This adaptation, which makes the nutrient-rich plant easy to pass through foraging animals, may have been its way of feeding nearby soil microbes. Botanists in China discovered this connection in the first analysis of the Broussonetia papyrifera genome ... Using comparative genetics, the research team also found that the paper mulberry tree developed a complex set of flavonoids. These compounds, commonly used in Chinese traditional medicine, can help a plant's roots attract nitrogen-fixing bacteria such as Pseudomonas and Rhizobia, which in turn promote leave and stem growth (a tactic commonly used by legumes), and enhance the paper mulberry's ability to adapt to a wide range of environments.
22. Nitrogen-fixing trees 'eat' rocks, play pivotal role in forest health: By tapping nutrients from bedrock, red alder trees play a key role in healthy forest ecosystems24 Feb 2019: Researchers ...determined red alder, through its symbiotic relationship with nitrogen-fixing bacteria, taps nutrients that are locked in bedrock, such as calcium and phosphorus. This process accelerates rock dissolution, releasing more mineral nutrients that allow plants and trees to grow. The study addresses the long-term implications of how nutrients make their way into ecosystems, which sustain their long-term growth and productivity and ultimately store carbon...
23. Coastal waters are unexpected hotspots for nitrogen fixation: New findings upend prevailing theories; ocean's role in carbon cycle isn't as we thought20 Feb 2019: Nitrogen fixation is surprisingly high in the ocean's coastal waters and may play a larger role than expected in carbon dioxide uptake, a new study shows. The findings -- based on thousands of samples collected in the western North Atlantic -- upend prevailing theories about where and when nitrogen fixation occurs, and underscore the need for scientists to revisit the global distribution of marine nitrogen fixation and reevaluate its role in the coastal carbon cycle.
24. Ocean fertilization by unusual microbes extends to frigid waters of Arctic Ocean9 Dec 2018: Microbes that provide natural fertilizer to the oceans by 'fixing' nitrogen from the atmosphere into a form useable by other organisms are active in the cold waters of the Bering and Chukchi Seas. ...Microbes that provide natural fertilizer to the oceans by "fixing" nitrogen from the atmosphere into a form useable by other organisms were once thought to be limited to warm tropical and subtropical waters. Now, however, researchers have documented nitrogen fixation by an unusual type of cyanobacteria in the cold waters of the Bering and Chukchi Seas.
25. Solving a 75-year-old mystery might provide a new source of farm fertilizer26 Nov 2018: The solution to a 75-year-old materials mystery might one day allow farmers in developing nations to produce their own fertilizer on demand, using sunlight and nitrogen from the air. Thanks to a specialized X-ray source at Lawrence Berkeley National Laboratory, researchers ... have confirmed the existence of a long-hypothesized interaction between nitrogen and titanium dioxide (TiO2) -- a common photoactive material also known as titania -- in the presence of light. The catalytic reaction is believed to use carbon atoms found as contaminants on the titania. If the nitrogen-fixing reaction can be scaled up, it might one day help power clean farm-scale fertilizer production that could reduce dependence on capital-intensive centralized production facilities and costly distribution systems that drive up costs for farmers in isolated areas of the world. Most of the world's fertilizer is now made using ammonia produced by the Haber-Bosch process, which requires large amounts of natural gas.