BIO-BASED INDIGO AGRICULTURAL SUPPLY CHAIN DEVELOPMENT

• Sponsoring Institution: National Institute of Food and Agriculture
• Project Status: COMPLETE
• Funding Source: SMALL BUSINESS GRANT
• Reporting Frequency: Annual
• Accession No.: 1009646
• Grant No.: 2016-33610-25469
• Cumulative Award Amt.: $100,000.00
• Proposal No.: 2016-00772
• Project Start Date: Aug 1, 2016
• Project End Date: Mar 31, 2017
• Grant Year: 2016
• Program Code: [8.12]- Small and Mid-Size Farms

Recipient Organization
STONY CREEK COLORS, INC.
3456 KNIGHT DR
WHITES CREEK,TN 371899188

Performing Department
(N/A)

Non Technical Summary
The market for natural colorants is growing. Trends in food, cosmetics, and textiles show consumers are concerned over the use of synthetic, petroleum-derived dyes and seek a more environmentally friendly option. However, manufacturers cannot compromise on quality, stability, or functionality of colorants in their products. Stony Creek Colors has recently proven its ability to grow indigo at scale in the Southeast U.S. partnering with local small and medium sized farmers as well as to process this crop into natural indigo dye which has been tested in the textile industry, representing the first time in over 100 years that natural indigo has been used commercially in a U.S. denim mill. Nearly all denim produced today is dyed will synthetic indigo dye, which is synthesized from harmful petroleum byproducts and toxic chemicals such as benzene, formaldehyde, and cyanide. By replacing this synthetic dye with a bio-based product, not only are toxic reagents and waste products removed for the supply chain, but small and medium sized farmers are able to generate sustainable revenues and keep agricultural land in agriculture.This project seeks to further progress made by Stony Creek Colors in the commercialization of natural indigo dye. The company will work under this project to improve the scalability of its planting and harvesting methods including mechanization and treatments which have previously not been applied to indigo as a crop. The company will also refine its factory unit operations processes to increase the purity and throughput of its factory in order to provide high purity consistent dye product at an industrial scale. Success in these research areas will lead to the ability to scale the agricultural and chemical processing aspects of the business to include significantly more farms and reach a higher factory efficiency. This will ultimately allow natural indigo dye to become more technically and economically competitive with synthetic indigo dye.

Animal Health Component

40%

Research Effort Categories

Basic

60%

Applied

40%

Developmental

(N/A)

Classification

Knowledge Area (KA)	Subject of Investigation (SOI)	Field of Science (FOS)	Percent
511	2299	2000	100%

Knowledge Area
511 - New and Improved Non-Food Products and Processes;

Subject Of Investigation
2299 - Miscellaneous and new crops, general/other;

Field Of Science
2000 - Chemistry;

Keywords

chemicals

dye

indigo

manufacturing

renewable

textile

Goals / Objectives
The major goal of this project is to make the agricultural production and chemical processing aspects of natural indigo dye production more efficient, predictable, repeatable, and scalable in order to further its commercialization. By improving these aspects of the planting, harvesting, processing, and final blending of natural indigo, Stony Creek Colors expects to demonstrate decreased agriculture and production risks while expanding the base of applicable small and medium scale growers, including tobacco farmers.Stony Creek Colors will pursue four primary objectives through the course of this project:Objective 1: Identify optimal conditions, treatments, and methods to enable direct-seeding of indigo versus the current transplant method.Objective 2: Optimize mechanical harvest methods for indigo to enable scalable production.Objective 3: Refine specific process operations to remove impurities and enhance material separation.Objective 4: Develop harvest and processing methods for Indigofera spp. (tropical indigo) in order to allow blending for desired final product consistency.

Project Methods
This project will address optimization in planting, harvest, processing, and final preparation of indigo crops and dyes. In the planting portion of the project, seeds will be methodically treated with varying physical and chemical pretreatments and planted in test plots. Germination rates will be measured, and plants will be assessed for growth rates and ultimately for yields in laboratory indigo assays as compared to traditional transplant-started plants. In the harvest portion of the project, mature crops will be mechanically harvested via a modified sickle bar with conveyor, a modified green beans harvester, and traditional soft core baler. Each of the harvested products will be visually assessed for leaf-to-stem ratio, leaf integrity, and field waste, and each will be assessed for harvest-time per acre and ease of operation. Subsequently, pilot batches from each harvest will be performed in the lab and in the processing facility to assess yield and byproducts. In the factory unit operations portion of the project, various configurations, speeds, and durations will be testing related to the mixing and settling portion of natural indigo production to promote industrial efficiency. Finally, in the post-production blending portion of the project, a tropical indigo test crop will be grown using high performing varieties grown in small research plots in 2015. Current methods for processing of Stony Creek's Japanese indigo will be tested and optimized for use in processing the tropical indigo test crop, and the product yield will be evaluated to validate laboratory testing from 2015. If the final product does indeed prove higher in purity than the Japanese indigo-based product, blending procedures will be developed to produce a consistent final product.

Progress 08/01/16 to 03/31/17

Outputs
Target Audience:The target audience for this project includes small and medium sized farmers in the Mid-south who stand to benefit from the increased applicability of indigo as a high-value diversification crop, as well as textile manufacturers who benefit from a more consistent and higher purity natural alternative to synthetic dyes. The PI has presented at local events and symposiums on this research project and the overall business and market for all-American natural indigo. The PI has met with at least 40 small and mid size farmers and farming organizations during this project period, both educating them on indigo production and identifying potential research and/or production partners. The PI also met with representatives from leading denim mills, brands, and independent fashion designers. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided? Nothing Reported How have the results been disseminated to communities of interest?Results from the seed pretreatment trails and direct seeding trials have directly informed the methods directed to 2017 indigo farmers in Robertson County, TN What do you plan to do during the next reporting period to accomplish the goals? Nothing Reported

Impacts
What was accomplished under these goals? Objective 1: Stony Creek Colors evaluated various gibberilic acid and potassium nitrate seed pretreatments to increase germination rates across its seed stock, with particular interest in interrupting the seed's proposed complex dormancy cycle. The experiemntal results were able to identify optimal gibberellic concentrations and soak times for markedly improving germinations rates while potassium nitrate treatments were generally ineffective. Mechanical scarification was evaluated for tropical varieties which have larger seeds and harder seed coats and was shown to substantially increase germination. Direct seeding trials were performed by the Universtiy of Tennessee Highland Rim Research and Education Center across a variety ofplanting variables including seed depth and seeding method,and showed demonstrable results which will be further analyzed during Phase II research. Plants started in greenhouses and plants directly sewn in the fields ulitimately showed comparable results with regard to leaf mass and indigo yield, though there was a substantial delay in when these values occured. Objective 2: Multiplemechanical harvest methods were devised, tested, and analyzed includinga modified sickle bar and conveyor system and modified greens and green beans harvesters. Pilot scale evaluations were made, resulting in a method which allowed for the stripping of whole leaves in the field, while leaving plant stems to more quickly regrow leaves. Factory batch extractionswere performed for each successful test and comapred against soft-core baling, with the new method far exceeding the performace of baling. This resulted in higher batch weights, higher leaf-to-stem ratios, less soil contamination, and ultimately higher yields. Objective 3: Stony Creek perfromed experiments on multiple mix tank schemes to promote high mix rates along with appropriate regimes for coagulation and flocculation and was able to identify a scalable process for its factory operations. The company was not able to attained its proposed differential settling of impurities or indigo colorant. Objective 4: Stony Creek Colors grew higher quantities of tropical indigo in 2016 (roughly 8,000 plants among various varieties) which allowed for further experimentation and validation of prior assumptions. Tropical indigo did bear higher yields per plant than Japanese, however this gain is overcome when considering that Japanese indigo is harvested thre times per season. The purity of the tropical indigo crude extract is typically higher than that resulting from Japanese indigo, but at factory scale in 2016, both plant types exceeded the targeted purity so blending strategies will not be necessary.

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