Biochar, a form of black carbon created from the pyrolysis of plant biomass, has been suggested as a soil amendment could sequester carbon, improve soil fertility, and increase crop yields. However relatively little research has been conducted on the use of biochar in Midwestern soils. During a three-year project, we conducted field experiments to assess the effect of biochar on crop yields and soil fertility on six Indiana vegetable farms. We also used a collaborative participatory research approach to co-manage the experiment with farmers and a structured student internship program in which the interns managed research plots, collected data, and assisted with key farm operations. Seventeen undergraduate students participated in the summer internship program. Biochar was applied in spring 2015 at three rates: 0, 10, and 20 t ha-1. Potatoes, kale, and tomatoes were grown respectively in 2015, 2016, and 2017. Biochar did not affect crop yields on any farm in any year and a majority of the farmers (66.7%) surveyed at the end of the 2017 growing season indicated that they would not recommend biochar to other farmers. The interns completed questionnaires before and at the end of their internships. They indicated that their experience increased their understanding of farm budgets, marketing, pest and soil management, and their interest in participating in research generally and in on-farm research specifically. All of the interns indicated that their overall experience was positive. Similarly, the farmers indicated that they considered their intern to be an asset to their farm and remained very interested in serving as a mentor for student interns. The use of a participatory research approach, coupled with a structured research internship, appears to have potential to increase farmer interest in and understanding of research and to increase the understanding of students of farm life and farm management.
Our project had four major goals: (1) on-farm assessments of biochar, (2) a structured student internship program, (3) workshops to collaboratively implement, assess, and if necessary modify the on-farm experiments and internship program, and (4) dissemination of information about biochar to the public through extension publications, key farmer meetings, and research conferences.
We hypothesized that biochar incorporated into soils on six Indiana farms would increase crop yields. We also hypothesized that a student internship program, in which the interns managed research plots, collected data, and assisted with key farm operations. would increase their understanding of farm budgets, marketing, pest and soil management, and their interest in participating in research generally and in on-farm research specifically.
The study was conducted at six organically managed vegetable and/or flower farms located in northern, central, and southern Indiana. The farmers were invited to participate based on their interest in biochar, farm size, type of crops, and to represent a range of experience and locations. Biochar, produced from beetle-killed pine pyrolyzed at 550 C, was incorporated into the soil to a depth of approximately 15.2 cm at three rates (0, 10, and 20 tons per hectare) in May 2015 at all six farms. A complete randomized design was used to assess the effect of biochar rate on potatoes in 2015, kale in 2016, and tomatoes in 2017. All aspects of crop and soil management , including crop and cultivar selection, were determined by university personnel and the farmers during meetings that were held at least twice each year. Marketability was determined by each farmer based on their experience selling to restaurants or directly to customers at farmer’s markets or farm stands. Soil cores were collected to a depth of 15.2 cm on July 2015 and on July 2017, bulked by plot for each farm, and analyzed. Student interns were screened from a state-wide pool of applicants who expressed an interest in working with biochar in a small farm setting. The interns were expected to work 20 hours per week and were paid a stipend for the 12 week position. Lodging was not included. The interns were asked to maintain the biochar plots, to record data on pests, and maintain a journal. Interns also worked directly with their host farmer to learn how to manage a small farm. Pre and post questionnaires were completed by the farmers and interns to assess their perceptions of the project and experimental results and to determine Mixed model analysis of variance was used to analyze yields and soil data within each farm.
Biochar did not affect any soil variable in 2015 or in 2017. Similarly, biochar did not affect marketable, unmarketable or total yields on any farm in any year. A majority (71%) of the interns were women and were enrolled in majors related to agriculture or natural resources. Most (82%) indicated that they had friends who farmed although less than a quarter of the interns grew up on a farm and less than a third had relatives who farm. The internships increased their understanding of marketing, crop, pest and soil fertility management, as well as of experimental design and implementation . They also reported increased understanding of biochar production and its effects on crops, soil properties, and soil fertility. All of the interns agreed or strongly agreed that their overall experience as well as their experience with their former mentor was positive and that they would recommend the program to other students. The farmers were surveyed at the end of each growing season. With the exception of one farmer in 2016, all the farmers agreed or strongly agreed that the project increased their understanding of experimental design and that they felt confident that they could design their own research experiment. They were very interested in developing research projects with other farmers and in working with University researchers. In all three years, they agreed or strongly agreed that they developed the experiment as a group and were given opportunities to express their opinions. All of the farmers agreed or strongly agreed in every year that they would recommend the program to other farmers and that the intern was an asset to their farm.
Our research does not support the use of biochar on vegetable farms in Indiana but does support the use of a structured on-farm internship to support research goals and to provide students with valuable experiences working on small acreage farms. We successfully completed an on-farm participatory research program on biochar and a summer internship program in which 17 interns contributed to the research project and learned about farm management. We substantially increased the understanding of our interns about several aspects of farm management as well as about biochar. We also increased the interest of our interns and participating farmers in on-farm research. Cumulatively, our experience suggests that combining a research internship program with farmer-driven research has great potential to increase the interest of farmers and students in agricultural research and to produce students with a much greater understanding and appreciation of farming. We communicated the results of our project through multiple presentations at state and national conferences.
Interns were selected based on their geographical location, ability to travel to the farm, interest in farming as a career, and references attesting to their reliability and strong work ethic. Applications were gathered by the research team and forwarded to the farmers who conducted interviews and made final selections. The interns were expected to work 20 hours per week and were paid a stipend for the 12 week position. Lodging was not included. The interns were asked to maintain the biochar plots, to record data on pests, and maintain a journal. Interns worked directly with their host farmer to learn how to manage a small farm. They also participated in an online meeting with the research team and other interns approximately every two weeks. A contract describing their responsibilities, appropriate behavior, and a mechanism for resolving disputes was signed by both the farmers and the interns at the onset of the internship.