Progress report for GNE22-299
Project Information
Leafy green amaranth (Amaranthus spp.) is a crop of economical and nutritional importance among minoritized ethnic communities within the Northeastern United States. Iron levels accumulating in this minor crop are comparable or higher to that of spinach and it’s a rich source of antioxidants. Importantly for this region is that it’s a heat-loving crop that has the potential to supplement locally grown spinach in summer months, therefore being called summer spinach. Despite the known benefits of this crop, farmers are still hesitant to introduce it due to its association as a weed, with the Pigweed taxa and its lack of recognition as a ‘mainstream leafy green’. This proposal aims to promote leafy green amaranth to Northeastern farmers as a new crop preferred as a leafy green by many consumer groups due to its familiarity and preference by such biocultural communities as well as its health attributes. This will be completed through the standardization of cultivation methods, along with a market-driven approach to assess grower and consumer concerns and demands. This project aims to be a first step towards a greater mission of providing non-Western, ethnoculturally preferred crops to the international communities that exist and grow in prominence in the Northeastern United States.
Project objectives:
- Complete variety trials on leafy green amaranth in an outdoor and hydroponic farm setting to compare yield and nutritional quality.
- Evaluate single harvest and multiple harvest methods based on yield, consumer preference, and environmental sustainability.
- Assess consumer response to the introduction of different varieties in farmers markets.
Parallel to the above objectives, collaborating farmers will be invited to tour the fields and provide their own assessment as to which leafy green amaranth cultivars are of greatest interest. In this way, we will be incorporating a ‘participatory approach’ to selection (pre-breeding strategies) based upon the industry inputs, therefore ensuring the relevancy and connections to small-scale New Jersey growers.
The purpose of this project is to promote the production and marketing of ethnoculturally preferred leafy green amaranth towards minoritized ethnic communities through year-round production systems, stressing cultural preference and nutrition.
Demand for ethnocultural leafy greens in the US is rising rapidly due to the increased awareness among cultural groups about their culinary heritage and the desire for diverse and healthy diets (Govindasamy et al., 2016). This demand is heightened when considering the disproportional effects of food insecurity on minoritized ethnic populations. Mousa and Freeland-Graves (2009) determined that food-insecure clients of food pantries were significantly more likely to have spent a shorter duration living in the US and were more overweight compared to those that were food secure. This is attributed to the lack of culturally familiar, nutrient-dense foods that are available at an affordable price. Leafy green amaranths (Amaranthus spp.) are among the most popular culturally preferred leafy greens across African Diaspora, Latino, South and East Asian communities (Govindasamy et al., 2016). These communities make up 65% of New Jersey’s population, according to the 2020 state census. This crop has the potential to serve as a model for ethnocultural crop introduction due to its immense cultural desire, nutritional capacity, and ease in growing.
The global use of amaranth as a leafy green makes it an optimal target for crop introduction in the Northeastern United States, which relies on high-value specialty crops. Along with ethnocultural favorability, amaranth plants are heat-loving and tolerant to drought and salt stress (Palmeros-Suárez et al., 2021). Its leaves are comparable to spinach in vitamin and mineral content (Chawla et al., 1988), which allows for the nickname of “Summer Spinach”. This marketing approach encourages the supplementation of spinach in summer months, increasing the availability of year-round locally grown produce in the Northeast. Amaranth is also being grown hydroponically as a baby green, which maximizes its production time and reduces its threat as a weedy species in open-field agriculture. Benefits of hydroponically grown leafy green amaranth also include maximization of nutritional content and cleaner harvested products (Gilmour et al., 2019).
Despite ethnocultural desire for amaranth, its production has not been made a priority to specialty crop farmers because of its association with the pigweeds of the Amaranthus genus. In reference to agricultural sustainability, this project strives to emphasize to farmers the importance of harvesting crops before they flower. Amaranth plants have limited root systems, so their weedy tendencies are due to the abundance of seeds produced by a single plant. Selection for very late flowering amaranth cultivars is a large consideration in these field trials to reduce likelihood of plants seeding in the field. Govindasamy et al. (2016) highlighted those current methods of crop rotation, cultivation and other weed control strategies used are sufficient means of recovering a mismanaged field of amaranth greens that go to seed. As consumer awareness of this crop increases, amaranth has the potential to penetrate Northeastern markets as an ethnoculturally familiar crop and as a summer alternative to spinach.
Research
- Complete variety trials on leafy green amaranth in an outdoor and hydroponic farm setting to compare yield and nutritional quality.
The summer 2021 growing season was dedicated to growing out 137 unique lines of amaranth collected from the USDA-GRIN seed bank, World Vegetable Center, and commercial seed companies. Using a participatory approach by interested growers, we were able to select 50 lines with high market potential. We will expand on this work with 3 subsequent variety trials on these 50 cultivars, focusing on yield-related traits including leaf area, plant height, stem diameter, plant fresh and dry weight. These cultivars will be observed in open-field environments in Rutgers experimental stations, first in Central and then Northern New Jersey using plasticulture and drip irrigation. Fertilizer and pesticide will not be sprayed on the crops, to determine those that perform the best and screen for pest and disease susceptibility. Seeds will first be sown in the greenhouse in May and then transplanted into the field in Mid-June. A randomized complete block design will be used, with 10 accessions of a single cultivar per plot and 3 blocks containing 50 plots each. This will total 1,500 individual plants. The plants will grow out for four weeks before harvesting. To stay consistent with the previous variety trial, plants will be harvested 10 nodes about the ground and fresh and dry weight will be collected. After harvesting, all plants will be completely removed from the field to avoid any flowering and dispersing seeds.
A third variety trial will be completed in an indoor hydroponic setting, using a Nutrient Film Technique (NFT) system that will be supplied through the funding of this grant and supplemental lighting, which has already been purchased. All conditions will be controlled, including pH, temperature, nutrient solution, and soluble salts. The seeds will be sown directly into the hydroponic system and will be harvested five weeks later by cutting the plant at the base. Each NFT system will be dedicated to one cultivar, observing 3 systems at once. It will take 16 months to complete this. Hydroponic systems will be controlled so each cultivar has the exact same growing conditions. Dried leaf samples from all variety trials will be saved and tested for vitamin and mineral content, along with antioxidants and abundance of pigments. The Central New Jersey field trial will be conducted from June 2022 to September 2022. The Northern New Jersey field trial will be completed June 2023 to September 2023. The hydroponic trials will be carried out in the greenhouse from October 2022 to June 2023 and continued from October 2023 to June 2024.
- Evaluate single harvest and multiple harvest methods based on yield and consumer preference and environmental sustainability.
After plants have been further selected for yield, nutritional properties, and cultural preference, the summer field trials will focus on optimizing crop production. Traditionally, amaranth is cut and allowed to regrow for subsequent harvests, or it is pulled from the ground once. The summer of 2024 will be dedicated to comparing the yield and nutritional value of crops subjected to multiple harvests and single harvests. For multiple harvest crops, seeds will be sown in May and transplanted in June. They will first be harvested 4 weeks after transplanting, 10 nodes above the ground. Fresh and dry weight will be collected, and dry leaf samples will be kept for nutritional analysis. Plants will then be allowed to grow back for four weeks and again harvested, collecting fresh and dry weight, and keeping dried leaves for nutritional analysis. This will be repeated once more for a total of 3 harvests, taking place from July to September. To complete the single harvest cultivation method, seeds will first be sown in May and transplanted in June. Plants will be completely pulled out of the ground after 4 weeks and fresh and dry weight will be recorded. New seeds will be sown in June for July transplanting and again in July for September transplanting. These plants will be transplanted four weeks after sowing and the whole plants harvested four weeks after transplanting. Dried leaves will be saved from each subsequent growth cycle and compared for nutritional analysis. The two harvest methods will be compared.
- Assess consumer response to the introduction of different varieties in farmers markets.
Because this research is focused on a market-driven approach to crop introduction, consumer feedback will be a large component of cultivar selection. Cultivars of interest to different ethnocultural communities – particularly African Diaspora, Latino, South and East Asian – will be presented at farmers markets along with voluntary surveys. Customers will be allowed to take samples home and prepare them, while completing a survey on appearance, taste, and texture characteristics. The 2022 summer variety trial will focus on working with growers to determine optimal harvesting time, as the young leaves are typically preferred. The summer variety trials of 2023 and 2024 will have plants being grown specifically for farmers’ market distribution.
2022 Update
As of January 2023, I have begun to build a controlled environment hydroponic growth chamber to begin amaranth indoor variety trials. My methods of hydroponic growing changed from what was originally proposed - mainly the use of an Ebb and Flow system rather than Nutrient Film Technique due to restrictions on the grow space provided. I have also completed a second outdoor variety trial for 38 lines of amaranth, both commercial and collected from the USDA-GRIN seed bank. All yield data has been collected and I am currently collecting nutritional data in the lab. I am beginning to prepare market surveys for the summer field season to determine favorable traits like taste, texture, and appearance.
2023 Update
As of February 2024, I have made significant progress in my outdoor variety trials, indoor hydroponic system, market surveys, and nutritional analysis of amaranth. After receiving IRB exemption this past summer, we piloted surveys in English, Mandarin, and Spanish at the Rutgers Cooks farmers market and New Brunswick community farmers’ market. We plan to continue these surveys in summer, 2024 at a larger capacity, which will involve shortening the surveys and sending them out to a wider audience throughout New Jersey in more locations.
Our hydroponic system has been designed and built, using an ebb-and-flow fertigation system and supplemental lighting to mimic a controlled indoor grow facility. The system is being tested before trials are conducted and we have been facing obstacles in plant health, which is likely attributed to the properties of our substrate, Rockwool. With assistance of Dr. AJ Both of Rutgers University, we have set up soilless substrate experiments evaluating plant growth in rockwool, peat/vermiculite, and greenhouse soil. We have already seen significant improvements in reduction of algae growth using peat/vermiculite and hope this will be the last issue needed to be resolved before we can begin our cultivar trials.
Under SARE’s funding for this grant, undergraduate student Erin Quinn was able to complete her honors thesis at Rutgers School of Environmental and Biological Sciences. Tori and Erin explored the impact of different supplemental lighting systems and harvests in different growth stages on overall yield and nutrition. This research was submitted for completion of Ms. Quinn’s honors thesis, mentored by Ms. Rosen.
In the summer of 2023, we completed a field study comparing early versus late summer crop cycles. Ten varieties of amaranth were used for this study, either Rutgers breeding lines or commercial varieties. Plants were grown out twice, once from June-July and again from August-September. Yield-related traits have been compared and nutritional traits are continuing to be evaluated.
As stated in our original grant, this summer we plan to complete our study on single versus multiple harvests of amaranth at Rutgers Hort Farm 3. We will be using our most promising Rutgers amaranth selections and breeding lines for this study, comparing yield-related traits, responses to insect pressure, and nutritional data.
Final Amaranth Survey Aug-Sept 2023, Final Mandarin Amaranth Survey Aug-Sept 2023, Final Edited Spanish Amaranth Survey Aug-Sept 2023 (1)
Education & Outreach Activities and Participation Summary
Participation Summary:
This study will directly involve New Jersey farmers and buyers in cultivar selections. Collaborating farmers will visit our open-field and hydroponic farms to make selections based on ethnocultural preferences of appearance, taste, and texture. These farmers will teach us about cultural culinary practices, and we will work with them on sustainable production to enhance amaranth production without allowing it to disperse seeds as well as provide the nutritional analysis on each. The team will visit multiple New Jersey farmers’ markets with our products to assess consumer interest and preferences. Results from outdoor and indoor variety trials will be presented at the New Jersey Vegetable Growers’ Conference in February of 2024. Results will also lead to multiple publications on the variety trials and controlled experiment looking at the impact of harvesting technique on yield and produce quality.
Outreach and extension are core components of crop introduction because without established market interest, farmers will not want to include amaranth as a summer vegetable. Outreach includes inviting growers to our own farms and visiting theirs, collaborating to determine the most economical ways to grow and sell leafy green amaranth and focus efforts in reaching targeted consumer groups that have indicated their preference to purchase but found product not to be available and accessible. This will lead to future opportunities to expand amaranth production out of the New Jersey/Northeastern United States into other areas with large international communities.
2023 Update
In the past year, this research has been presented at the New Jersey Vegetable Growers Convention in Atlantic City, NJ and the Rutgers University Climate Symposium in New Brunswick, NJ. Through Northeast SARE, Ms. Rosen was invited to be a keynote lunch speaker at Snyder Research Farm, explaining the ongoing research to farmers and extension agents affiliated with SARE. This research was also shown to Rutgers Alumni at a Science-in-Action movie screening event, as a 3-minute trailer about our ongoing amaranth research.
Project Outcomes
Our extension work has highlighted the importance of amaranth as a climate-resilient crop, due to its resistance to abiotic stresses, namely drought and heat stress. We highlight the importance of adapting our agricultural models to find more climate-resilient crop alternatives to traditional leafy greens. Our showcasing of amaranth at farmers markets has helped introduce the crop to climate-smart shoppers, who prioritize locally grown seasonal produce at farmers markets. Consumers are excited about the idea of a replacement for spinach in the summer months and even without cultural familiarity, are willing to buy it as a locally sourced replacement. In our extension work, we also make a clear effort to discuss avoiding the production of flowers on plants in the field, to reduce its likelihood to grow in subsequent years. By harvesting the complete plant 6 weeks after sowing, we are ensuring that it does not grow back and begin to flower.
We have learned a great deal about prioritizing data collected in consumer surveys. There were questions that we had originally found very straightforward which we learned that participants struggled to understand. We also learned the importance in keeping surveys short, as participants are much less likely to have meaningful responses in surveys over 3-5 minutes, especially as they are shopping at the farmers markets.
We have also learned that hydroponic production takes an enormous amount of trial and error, even when everything looks good on paper. There is almost no literature on hydroponic production of amaranth, so parameters were based mostly on spinach production. Even with pH and EC values looking good on paper, plants may still struggle to survive for a variety of reasons. For example, we have struggled with finding a soilless substrate that limits algae growth and has a lower water holding capacity, as amaranth does not require a lot of water to grow. These unanticipated results have led to many more research questions and ultimately we aim to publish a guide to hydroponic cultivation of amaranth for indoor growers in the Northeast.