Agriculture is facing numerous challenges in the 21st century, including the need to feed a growing global population, adapt to climate change, and reduce the environmental impact of farming practices. To address these challenges, innovative solutions are needed that can enhance crop productivity, resilience, and sustainability. One such solution is the use of microbial seed coatings, a technology that harnesses the power of beneficial microorganisms to improve plant growth, health, and stress tolerance.
Indigo Ag, a Boston-based agricultural technology company, has emerged as a leader in the development and commercialization of microbial seed coatings. Indigo's microbial seed coatings are based on the discovery and application of endophytes, a class of microorganisms that live within plant tissues and provide a range of benefits to their host plants. By coating seeds with these beneficial endophytes, Indigo aims to unlock the full potential of crops and create a more sustainable and resilient agriculture system.
Science of Microbial Seed Coatings
The Plant Microbiome
To understand the science behind microbial seed coatings, it is important to first understand the concept of the plant microbiome. The plant microbiome refers to the complex community of microorganisms that live in and around plants, including bacteria, fungi, viruses, and other microbes. These microorganisms play a critical role in plant growth, development, and health, by providing a range of functions and services to their host plants.
Some of the key functions of the plant microbiome include:
- Nutrient acquisition: Many microorganisms in the plant microbiome are involved in the acquisition and cycling of essential plant nutrients, such as nitrogen, phosphorus, and potassium. For example, some bacteria can fix atmospheric nitrogen into a form that plants can use, while others can solubilize phosphorus from soil minerals.
- Disease suppression: Some microorganisms in the plant microbiome can protect plants from pathogens and pests, by producing antimicrobial compounds, competing with pathogens for resources, or inducing plant defense responses.
- Stress tolerance: Some microorganisms in the plant microbiome can help plants tolerate abiotic stresses, such as drought, salinity, and extreme temperatures, by producing stress-protective compounds, modifying plant physiology, or enhancing root growth and water uptake.
- Plant growth promotion: Some microorganisms in the plant microbiome can promote plant growth and development, by producing plant growth hormones, such as auxins and cytokinins, or by modulating plant gene expression and metabolism.
The composition and function of the plant microbiome are influenced by a range of factors, including the plant species and genotype, the soil type and properties, the climate and environment, and the management practices used in agriculture. Understanding and harnessing the plant microbiome has emerged as a key frontier in agriculture research and innovation, with the potential to enhance crop productivity, resilience, and sustainability.
Endophytes: A Key Component of the Plant Microbiome
Endophytes are a specific class of microorganisms that live within plant tissues, such as leaves, stems, and roots, without causing any apparent harm to their host plants. Endophytes are found in virtually all plant species and can include bacteria, fungi, and other microbes. Unlike other plant-associated microorganisms, such as rhizosphere bacteria or mycorrhizal fungi, endophytes have the unique ability to colonize the internal tissues of plants and establish a mutualistic relationship with their hosts.
Endophytes have attracted increasing attention in recent years, due to their potential to provide a range of benefits to plants, including:
- Nutrient acquisition: Some endophytes can help plants acquire nutrients from the soil, by producing enzymes that can break down complex organic compounds or by fixing atmospheric nitrogen.
- Disease resistance: Some endophytes can protect plants from pathogens, by producing antimicrobial compounds, competing with pathogens for space and resources, or inducing plant defense responses.
- Stress tolerance: Some endophytes can help plants tolerate abiotic stresses, such as drought, salinity, and extreme temperatures, by producing stress-protective compounds, such as osmoprotectants and antioxidants, or by modifying plant physiology and gene expression.
- Plant growth promotion: Some endophytes can promote plant growth and development, by producing plant growth hormones, such as auxins and cytokinins, or by modulating plant metabolism and gene expression.
The ability of endophytes to provide these benefits to plants has made them a promising target for agricultural biotechnology and innovation. By harnessing the power of endophytes, it may be possible to develop new tools and strategies for enhancing crop productivity, resilience, and sustainability, without relying on synthetic inputs or genetic modification.
The Discovery and Development of Indigo's Microbial Seed Coatings
Indigo Ag was founded in 2014 with the mission of harnessing the power of the plant microbiome to create a more sustainable and resilient agriculture system. The company's founding team, led by CEO David Perry, recognized the potential of endophytes as a key component of the plant microbiome and set out to discover and develop new microbial technologies for agriculture.
Indigo's approach to discovering and developing microbial seed coatings involves several key steps:
- Microbiome sequencing: Indigo uses advanced sequencing technologies, such as metagenomics and metatranscriptomics, to characterize the microbiome of plants grown in different environments and under different stress conditions. This allows the company to identify the key microbial taxa and functions that are associated with plant health and productivity.
- Isolation and screening: Based on the microbiome sequencing data, Indigo isolates and screens individual microbial strains for their ability to colonize plants and provide beneficial functions, such as nutrient acquisition, disease resistance, and stress tolerance. This involves testing the microbes in laboratory and greenhouse assays, as well as in field trials.
- Formulation and delivery: Once promising microbial strains are identified and validated, Indigo develops formulations and delivery methods that allow the microbes to be efficiently coated onto seeds and persist in the plant throughout its life cycle. This involves optimizing the growth conditions, carriers, and additives used in the seed coating process, as well as testing the stability and efficacy of the coated seeds under different storage and planting conditions.
- Commercialization and stewardship: Indigo works with seed companies, farmers, and other partners to bring its microbial seed coatings to market and ensure their responsible and sustainable use. This involves conducting extensive field trials and demonstrations, providing technical support and training, and developing protocols and best practices for the use of the microbial seed coatings in different crops and regions.
Through this process, Indigo has developed a portfolio of microbial seed coatings for a range of crops, including corn, soybeans, wheat, cotton, and rice. These coatings are marketed under the brand names Indigo Cotton, Indigo Wheat, Indigo Corn, and Indigo Soybeans, and are available through Indigo's partner seed companies and retailers.
Benefits and Applications of Indigo's Microbial Seed Coatings
Yield Improvement
One of the primary benefits of Indigo's microbial seed coatings is their potential to improve crop yields. By providing plants with beneficial endophytes that can enhance nutrient acquisition, disease resistance, and stress tolerance, Indigo's seed coatings can help crops achieve higher yields under a range of growing conditions.
In field trials and commercial plantings, Indigo's microbial seed coatings have demonstrated significant yield improvements across a range of crops and geographies. For example:
- Indigo Cotton: In a 2019 field trial in Texas, cotton plants treated with Indigo's microbial seed coating yielded an average of 11% more lint per acre than untreated plants, with some fields showing yield improvements of up to 19%. Similar yield improvements have been observed in other cotton-growing regions, such as Georgia and Mississippi.
- Indigo Wheat: In a 2020 field trial in Kansas, wheat plants treated with Indigo's microbial seed coating yielded an average of 3.7 bushels per acre more than untreated plants, with some fields showing yield improvements of up to 8 bushels per acre. Similar yield improvements have been observed in other wheat-growing regions, such as Oklahoma and North Dakota.
- Indigo Corn: In a 2020 field trial in Iowa, corn plants treated with Indigo's microbial seed coating yielded an average of 7.2 bushels per acre more than untreated plants, with some fields showing yield improvements of up to 12 bushels per acre. Similar yield improvements have been observed in other corn-growing regions, such as Illinois and Nebraska.
- Indigo Soybeans: In a 2020 field trial in Minnesota, soybean plants treated with Indigo's microbial seed coating yielded an average of 2.1 bushels per acre more than untreated plants, with some fields showing yield improvements of up to 4 bushels per acre. Similar yield improvements have been observed in other soybean-growing regions, such as Indiana and Ohio.
These yield improvements can translate into significant economic benefits for farmers, by increasing their productivity and profitability. For example, a 3.7 bushel per acre yield improvement in wheat, at a price of $5 per bushel, would represent an additional $18.50 per acre in revenue for farmers. Similarly, a 7.2 bushel per acre yield improvement in corn, at a price of $4 per bushel, would represent an additional $28.80 per acre in revenue for farmers.
Disease Resistance
Another key benefit of Indigo's microbial seed coatings is their potential to enhance disease resistance in crops. Many of the endophytes used in Indigo's seed coatings have been selected for their ability to protect plants from a range of bacterial, fungal, and viral pathogens, through mechanisms such as antibiosis, competition, and induced systemic resistance.
In field trials and commercial plantings, Indigo's microbial seed coatings have demonstrated significant reductions in disease incidence and severity across a range of crops and pathogens. For example:
- Indigo Cotton: In a 2019 field trial in Texas, cotton plants treated with Indigo's microbial seed coating showed a 50% reduction in the incidence of Fusarium wilt, a fungal disease that can cause significant yield losses. Similar reductions in Fusarium wilt have been observed in other cotton-growing regions, such as Georgia and California.
- Indigo Wheat: In a 2020 field trial in North Dakota, wheat plants treated with Indigo's microbial seed coating showed a 40% reduction in the severity of Fusarium head blight, a fungal disease that can reduce grain quality and yield. Similar reductions in Fusarium head blight have been observed in other wheat-growing regions, such as Minnesota and Ohio.
- Indigo Corn: In a 2020 field trial in Illinois, corn plants treated with Indigo's microbial seed coating showed a 60% reduction in the incidence of Goss's wilt, a bacterial disease that can cause significant yield losses. Similar reductions in Goss's wilt have been observed in other corn-growing regions, such as Iowa and Nebraska.
- Indigo Soybeans: In a 2020 field trial in Indiana, soybean plants treated with Indigo's microbial seed coating showed a 30% reduction in the severity of sudden death syndrome, a fungal disease that can reduce yield and seed quality. Similar reductions in sudden death syndrome have been observed in other soybean-growing regions, such as Illinois and Missouri.
By reducing the impact of diseases on crops, Indigo's microbial seed coatings can help farmers maintain yield and quality, while reducing their reliance on chemical fungicides and other inputs. This can lead to significant economic and environmental benefits, by lowering production costs, improving profitability, and reducing the risk of pesticide resistance and off-target impacts.
Stress Tolerance
A third key benefit of Indigo's microbial seed coatings is their potential to enhance stress tolerance in crops. Many of the endophytes used in Indigo's seed coatings have been selected for their ability to help plants tolerate abiotic stresses, such as drought, heat, and salinity, through mechanisms such as osmotic adjustment, antioxidant production, and root growth promotion.
In field trials and commercial plantings, Indigo's microbial seed coatings have demonstrated significant improvements in crop performance under stress conditions across a range of crops and environments. For example:
- Indigo Cotton: In a 2019 field trial in Texas, cotton plants treated with Indigo's microbial seed coating showed a 20% increase in yield under drought stress conditions, compared to untreated plants. Similar improvements in drought tolerance have been observed in other cotton-growing regions, such as Arizona and California.
- Indigo Wheat: In a 2020 field trial in Kansas, wheat plants treated with Indigo's microbial seed coating showed a 15% increase in yield under heat stress conditions, compared to untreated plants. Similar improvements in heat tolerance have been observed in other wheat-growing regions, such as Oklahoma and Texas.
- Indigo Corn: In a 2020 field trial in Nebraska, corn plants treated with Indigo's microbial seed coating showed a 10% increase in yield under water-limited conditions, compared to untreated plants. Similar improvements in drought tolerance have been observed in other corn-growing regions, such as Colorado and Kansas.
- Indigo Soybeans: In a 2020 field trial in Arkansas, soybean plants treated with Indigo's microbial seed coating showed a 12% increase in yield under salt stress conditions, compared to untreated plants. Similar improvements in salt tolerance have been observed in other soybean-growing regions, such as Mississippi and Louisiana.
By enhancing crop resilience to abiotic stresses, Indigo's microbial seed coatings can help farmers maintain yield and quality under challenging growing conditions, such as drought, heat waves, and soil salinity. This can be particularly important in regions where climate change is expected to increase the frequency and intensity of these stresses, and where water and other resources are becoming increasingly limited.
Sustainability and Environmental Benefits
In addition to their direct benefits for crop productivity and resilience, Indigo's microbial seed coatings also have the potential to provide significant sustainability and environmental benefits. By reducing the need for synthetic fertilizers, pesticides, and other inputs, microbial seed coatings can help to mitigate some of the negative impacts of agriculture on soil health, water quality, and biodiversity.
Some of the key sustainability and environmental benefits of Indigo's microbial seed coatings include:
- Reduced fertilizer use: By enhancing nutrient acquisition and cycling in the plant-soil system, microbial seed coatings can reduce the need for synthetic fertilizers, particularly nitrogen and phosphorus. This can help to mitigate the environmental impacts of fertilizer production and application, such as greenhouse gas emissions, water pollution, and soil degradation.
- Reduced pesticide use: By enhancing disease resistance and pest suppression in crops, microbial seed coatings can reduce the need for chemical fungicides and insecticides. This can help to mitigate the environmental impacts of pesticide use, such as non-target effects on beneficial organisms, pesticide resistance, and human health risks.
- Improved soil health: By promoting the growth and activity of beneficial soil microbes, microbial seed coatings can help to improve soil structure, fertility, and biodiversity. This can lead to a range of ecosystem services, such as carbon sequestration, water retention, and nutrient cycling, which are essential for long-term soil health and productivity.
- Reduced water use: By enhancing drought tolerance and water use efficiency in crops, microbial seed coatings can reduce the need for irrigation and other water inputs. This can help to conserve limited water resources, particularly in arid and semi-arid regions, and reduce the energy and emissions associated with water pumping and distribution.
- Enhanced biodiversity: By reducing the use of synthetic inputs and promoting the growth of diverse microbial communities, microbial seed coatings can help to support and enhance biodiversity in agricultural landscapes. This can provide a range of ecosystem services, such as pollination, pest control, and nutrient cycling, which are essential for the long-term sustainability and resilience of agriculture.
To quantify and communicate these sustainability and environmental benefits, Indigo has developed a range of metrics and tools, such as the Indigo Carbon program, which aims to help farmers and other stakeholders measure, report, and verify the carbon sequestration and greenhouse gas reductions associated with the use of microbial seed coatings and other regenerative agriculture practices. By providing a science-based and transparent framework for assessing and valuing these benefits, Indigo aims to create new market opportunities and incentives for the adoption of sustainable agriculture practices, and to contribute to the broader goals of climate change mitigation, biodiversity conservation, and ecosystem restoration.
Challenges and Limitations of Microbial Seed Coatings
Despite the many potential benefits of microbial seed coatings, there are also several challenges and limitations that need to be addressed to ensure their effective and sustainable use in agriculture. Some of the key challenges and limitations include:
Variability and Inconsistency
One of the main challenges of microbial seed coatings is the variability and inconsistency of their performance across different crops, environments, and management practices. Unlike synthetic inputs, which are designed to provide a consistent and predictable response, microbial seed coatings are living organisms that are influenced by a range of biotic and abiotic factors, such as soil type, temperature, moisture, and plant genotype.
This variability can make it difficult to predict and optimize the effectiveness of microbial seed coatings, and can lead to inconsistent or even negative results in some cases. For example, a microbial seed coating that performs well in one field or season may not perform as well in another field or season, due to differences in soil properties, weather conditions, or management practices.
To address this challenge, Indigo and other companies are investing in extensive field testing and data analytics to better understand and predict the performance of microbial seed coatings under different conditions. This involves conducting multi-year, multi-location trials across a range of crops and environments, and using advanced data science tools to identify the key factors that influence the effectiveness of microbial seed coatings. By leveraging this data and knowledge, companies can develop more targeted and customized microbial seed coating products and recommendations, and provide farmers with more reliable and consistent results.
Compatibility and Interaction with Other Inputs
Another challenge of microbial seed coatings is their potential compatibility and interaction with other agricultural inputs, such as fertilizers, pesticides, and growth regulators. While microbial seed coatings are designed to be complementary to other inputs, there is still a risk of negative interactions or incompatibilities that could reduce their effectiveness or even harm the crop.
For example, some pesticides or fertilizers may have antimicrobial properties that could kill or inhibit the growth of the beneficial microbes in the seed coating. Similarly, some microbial seed coatings may produce compounds that could interact with other inputs, such as hormones or enzymes, and alter their effects on the crop.
To address this challenge, Indigo and other companies are conducting extensive compatibility testing and research to identify the optimal combinations and application methods for microbial seed coatings and other inputs. This involves studying the effects of different input formulations, rates, and timings on the survival and activity of the microbial seed coatings, as well as on the growth and health of the crop. By developing integrated and holistic management strategies that consider the interactions and synergies between different inputs, companies can help farmers optimize the benefits and minimize the risks of using microbial seed coatings in their operations.
Regulatory and Safety Considerations
A third challenge of microbial seed coatings is the regulatory and safety considerations around their development, testing, and commercialization. Like other agricultural inputs, microbial seed coatings are subject to various regulations and standards aimed at ensuring their safety, efficacy, and environmental impact.
However, the regulatory framework for microbial seed coatings is still evolving and varies across different countries and regions. In the United States, for example, microbial seed coatings are regulated by the Environmental Protection Agency (EPA) under the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA), which requires companies to register their products and demonstrate their safety and efficacy through extensive testing and data submission.
In addition to the regulatory requirements, there are also potential safety and environmental risks associated with the use of microbial seed coatings that need to be carefully assessed and managed. For example, some microbial seed coatings may have the potential to cause allergic reactions or other health effects in humans or animals, or to persist and spread in the environment in unintended ways.
To address these challenges, Indigo and other companies are investing in rigorous safety testing and risk assessment protocols to ensure the safety and sustainability of their microbial seed coating products. This involves conducting extensive toxicological and ecological studies to evaluate the potential impacts of the microbial seed coatings on human and animal health, as well as on non-target organisms and ecosystems. By developing transparent and science-based safety and stewardship practices, companies can help to build public trust and confidence in the use of microbial seed coatings, and ensure their responsible and beneficial use in agriculture.
Cost and Accessibility
A fourth challenge of microbial seed coatings is their cost and accessibility, particularly for smallholder farmers in developing countries. While microbial seed coatings have the potential to provide significant benefits for crop productivity and sustainability, they also require additional costs and investments compared to conventional seed treatments or no treatment.
These costs can include the research and development expenses associated with discovering, testing, and commercializing new microbial strains, as well as the production and distribution costs of the seed coating products themselves. In addition, farmers may need to invest in new equipment, training, or management practices to effectively use and optimize the benefits of microbial seed coatings.
For smallholder farmers in developing countries, who often have limited access to credit, markets, and extension services, these costs and investments can be significant barriers to adoption. In addition, the lack of infrastructure, supply chains, and quality control systems in many developing countries can make it difficult to ensure the consistent and reliable delivery of high-quality microbial seed coating products to farmers.
To address these challenges, Indigo and other companies are exploring innovative business models and partnerships to make microbial seed coatings more accessible and affordable for smallholder farmers. This includes developing low-cost and locally-adapted formulations and delivery methods, as well as partnering with local seed companies, agro-dealers, and extension services to provide training, support, and quality assurance to farmers.
In addition, there are also opportunities to leverage public-private partnerships and international development programs to support the scaling and adoption of microbial seed coatings in developing countries. For example, the Bill and Melinda Gates Foundation has funded several projects to develop and disseminate microbial technologies for smallholder farmers in Africa and Asia, as part of its efforts to improve food security and resilience in these regions.
Future Directions and Opportunities
Looking forward, there are many exciting opportunities and directions for the continued development and application of microbial seed coatings in agriculture. Some of the key areas of focus and potential include:
Expanding the Range of Crops and Traits
While Indigo and other companies have already developed microbial seed coatings for several major crops, such as corn, soybeans, wheat, and cotton, there is still significant potential to expand the range of crops and traits that can benefit from this technology.
For example, there are many other important food and fiber crops, such as rice, potato, tomato, and sugarcane, that could benefit from microbial seed coatings to improve their yield, quality, and stress tolerance. In addition, there are also many other desirable traits, such as enhanced nutrient content, flavor, or shelf life, that could be targeted through the use of specific microbial strains or combinations.
To realize this potential, companies will need to continue to invest in the discovery, screening, and development of new microbial strains and formulations that are adapted to the specific needs and challenges of different crops and environments. This will require ongoing collaborations and partnerships with academic researchers, government agencies, and other stakeholders to access and leverage the latest scientific knowledge and tools, such as genomics, metabolomics, and synthetic biology.
Integrating with Other Sustainable Agriculture Practices
Another key opportunity for microbial seed coatings is to integrate them with other sustainable agriculture practices and technologies, such as conservation tillage, cover cropping, precision agriculture, and digital tools. By combining microbial seed coatings with these other practices, farmers can create synergistic and complementary benefits for soil health, water conservation, carbon sequestration, and other ecosystem services.
For example, the use of microbial seed coatings in combination with cover cropping and reduced tillage can help to promote the growth and diversity of beneficial soil microbes, which can enhance nutrient cycling, water retention, and disease suppression in the crop. Similarly, the use of precision agriculture tools, such as variable rate planting and fertilization, can help to optimize the placement and performance of microbial seed coatings based on site-specific soil and crop conditions.
To facilitate this integration, companies will need to develop and promote holistic and systems-based approaches to sustainable agriculture, that consider the interactions and trade-offs between different practices and technologies. This will require ongoing research and education to help farmers and other stakeholders understand and adopt these integrated approaches, as well as policy and market incentives to support their widespread adoption and scaling.
Enabling New Business Models and Value Chains
A third key opportunity for microbial seed coatings is to enable new business models and value chains that can create additional value and benefits for farmers, consumers, and other stakeholders. By differentiating and branding crops produced with microbial seed coatings, companies can create new market opportunities and premium prices for farmers, as well as new ways to communicate and deliver the sustainability and health benefits of these products to consumers.
For example, Indigo has developed the Indigo Carbon program, which aims to help farmers generate and sell carbon credits based on the greenhouse gas reductions and soil carbon sequestration associated with the use of microbial seed coatings and other regenerative agriculture practices. By creating a new revenue stream for farmers, and a new way to finance and scale the adoption of sustainable practices, this program has the potential to transform the economics and incentives of agriculture.
Similarly, there are also opportunities to create new value chains and partnerships that can link farmers using microbial seed coatings with food and beverage companies, retailers, and other downstream players that are looking to source and market more sustainable and healthy products. By developing transparent and traceable supply chains, and communicating the unique attributes and benefits of these products to consumers, these partnerships can create new sources of value and differentiation for all stakeholders.
To realize these opportunities, companies will need to continue to innovate and experiment with new business models, marketing strategies, and partnerships that can align the interests and incentives of different players across the value chain. This will require ongoing collaboration and dialogue with farmers, consumers, policymakers, and other stakeholders to identify and address the key barriers and enablers of these new approaches.
Conclusion
Microbial seed coatings, as exemplified by Indigo's products and platform, represent a promising and transformative technology for sustainable agriculture. By harnessing the power of beneficial microbes to enhance crop productivity, resilience, and environmental performance, microbial seed coatings have the potential to address some of the most pressing challenges facing agriculture today, from climate change and resource scarcity to food security and ecosystem degradation.
However, realizing the full potential of microbial seed coatings will require ongoing research, innovation, and collaboration to address the key challenges and limitations of this technology, from variability and inconsistency to cost and accessibility. It will also require a systems-based and holistic approach that considers the interactions and synergies between microbial seed coatings and other sustainable agriculture practices and technologies, as well as the broader social, economic, and environmental contexts in which they are used.
As we look to the future, there are many exciting opportunities and directions for the continued development and application of microbial seed coatings, from expanding the range of crops and traits to enabling new business models and value chains. By leveraging these opportunities, and working together across disciplines, sectors, and geographies, we can create a more sustainable, resilient, and equitable food system that can meet the needs of a growing and changing world.
Ultimately, the success of microbial seed coatings will depend not only on their technical performance and economic viability, but also on their social and environmental impact, and their alignment with the values and aspirations of farmers, consumers, and other stakeholders. By engaging and empowering these stakeholders, and creating a shared vision and roadmap for the future of agriculture, we can unlock the full potential of microbial seed coatings and other sustainable agriculture innovations, and create a more abundant, diverse, and regenerative food system for all.