The farm is an 82 acre area on gentle hills with a creek and an artificial pond. Half of the land has been in hay production for 40 years, and the other half is forest, with trees up to 2 feet in diameter. The experimental farming area is 10,000 square feet, divided into 30 plots of 15-20' x 20', on a gently south sloping hay field. There are 5 rows of plots, separated by wood-core berms and 4-foot paths. Each row of plots is divided in half so that one half are control (conventional) soil management, and the other half are managed in pursuit of a chemically balanced soil chemistry. The control and intervention sides of each row are separated by a 15 foot area of mown grass. The top two rows have intervention plots to the west, and the bottom three rows have control plots to the west. The balanced side management also includes large amounts of composted leaves and coffee grounds, and small amounts of biochar or charcoal. Biochar is recovered from burn piles, an aerobic biochar rig that extinguishes hot coals, or anaerobic pyrolysis tubes. Biochar is mixed into compost immediately after production, and eventually the mixture is spread over intervention plots with other amendments, and tilled to a depth of 4-5 inches. The oldest intervention plots have been in development for 6 years. Cover crops of wheat, rye, or field peas grow through crop residues over the winter, and have been used for 2 years.
The farm's main crop is hay. The experimental field is planted with multiple varieties of amaranth, sweet corn, cowpeas, okra, sweet potatoes, pumpkins, sunflowers, and in the winter, rye, wheat, and peas as cover crops.
Manyprocesses inconventional farming could cause trace element deficiencies in row crops, while crop selection and rising CO2levels sustain or increase carbohydrate and calorie content. If food has a low ratio of trace elements to calories, consumers may overeat calories to acquire sufficient trace elements. The resulting nutritional imbalance will affect health, but some effects may be quickly reversible.
We are experimenting with sustainable, “balanced” fields, amended with major chemicals as guided by soil analyses, and with organic matter and trace elements from a low cost compost of tree leaves, spent coffee grounds, and charcoal made from waste debris and chaff. Compared to control fields managed with only lime and nitrogen, our crops grow faster and yield qualitatively different produce in balanced fields. In 2018 we prepared samples of multiple high yield, nutrient-dense crops for trace element analysis, including winter wheat, amaranth, okra, sweet potatoes, and pumpkins. For most crops, we are obtaining one trace element analysis in each growing condition. To prepare for human studies of nutrient dense crops on health, we seek SARE funding to conduct additional analyses of trace elements, selected organic compounds, macronutrients, and calories from staple crops in balanced and control growing conditions.
1. Calculate ratios of trace elements and selected essential nutrients to calories in crops grown with conventional fertilizers versus balanced amendments of organic matter, major, and trace elements. The hypothesis is that these ratios will be lower in conventional compared to balanced field crops.
2. Pilot test a year-long schedule for providing diabetic human subjects with a diet based on seas, trees, and rich row crops versus conventional diabetic diet advice and row crops. This will determine resource requirements for human studies using nutrient dense foods to prevent infections in diabetic employees, replicating a similar 2003 study of multivitamins.
Our experimental field supports fractional factorial designs to compare long-term conventional soil management to sustainable, nutrient-balanced management. The experimental field is a fenced area of 120’ north-south by 150’ east-west, with a gentle 2’ drop from north to south, just below a forest and above the floodplain. The conventional areas are the 70×70’ southwest corner (established in 2018) and 40×70’ northeast corner (2019). These areas receive calcium carbonate to correct soil pH, and nitrogen fertilizer at labelled rates. The balanced areas are the 70×70’ southeast corner (2016) and ~30×70’ northwest corner (2019). Balanced areas receive annual major element amendments guided by soil analyses and Solomon and Reinheimer’s Organicalc (https://growabundant.com/organicalc/), and trace elements primarily from tree leaf and coffee ground composted with fine charcoal.
The field is divided into rows of 15-20×20’ subplots. Water capturing swales and 3” wood-core berms line the south edge of subplot rows. Crop debris is left on fields. We use shallow tilling for initial weeding and soil preparation before paper pot transplanting. Winter wheat, rye, and Austrian field peas are used as cover crops.
Preferred crops are resilient, versatile, and nutrient dense. Amaranth, okra, and pumpkin have edible leaves, fruit, and seeds; tolerate hot weather; and can be grown as microgreens or row crops, as can sunflowers. Sweet potatoes have edible leaves and tubers, and compliment okra. Winter wheat, rye, and peas tolerate cold weather and produce edible seeds. Corn and wheat are staple crops, and amaranth could be.
Identical species are grown in conventional and balanced subplots, and harvested simultaneously. Crop samples are dried to constant weight and powdered in a food processor. The OSU STAR laboratory will perform elemental analyses on 5g samples. Midwest laboratories will perform macronutrient, kilocalorie, vitamin, lipid, and amino acid analyses on powdered 50-250g samples.
Midyear update, October 2019
After submitting the original budget, it became clear that Midwest Laboratories could analyze proximates and minerals simultaneously in samples submitted for their animal feed “F9” testing, and that some vitamins could be analyzed at less expense as animal feed rather than human food. Consequently the original budget categories are revised.
In addition, a report in the bioinformatics literature pointed to another strategy for selecting nutrients of interest. Scott-Boyer et al* reported that Mg, Zn, and vitamins B1, B2, and B6 are cofactors for many enzymes that are related to type II diabetes in GWAS studies. My review of KEGG biosynthetic pathways and BRENDA enzyme data suggested that all 3 vitamins have 2 or more synthetic steps in which Mg++ or Zn++ are preferred cofactors, and we already had some data suggesting higher Mg levels in intervention soil crops. A pilot test suggested that amaranth content of B6 might be especially sensitive to soil management, and that other B vitamins might be affected, but less dramatically. Consequently, analyses of several B vitamins were done in amaranth and rye samples. Wheat samples were collected but large amounts were lost to rodents while drying, leaving too little material to conduct the suite of analyses in triplicate for each growing condition.
* Scott-Boyer MP, Lacroix S, Scotti M, Morine MJ, Kaput J, Priami C. A network analysis of cofactor-protein interactions for analyzing associations between human nutrition and diseases. Sci Rep 2016;6:19633.
Midyear update, October 2019
The spring of 2019 saw record-breaking rainfall across the midwest, which complicated shallow tilling efforts in the new fields, especially 4 of the 6 new intervention plots, where the tractor repeatedly got stuck in mud. Eventually rows were double-dug by hand throughout the 12 new control and intervention plots. Plants grew very poorly at first, prompting a mid-summer soil analysis which was mainly remarkable for a pH of 5.2 for the 6 new intervention plots, in spite of what was expected to have been adequate lime application in the spring. In September a home garden pH meter was used to construct an extensive pH map of the entire experimental area (at least 1 sample per plot for all 30 plots, and 6 samples per plot for the 3 most suspect of the 6 new intervention plots (mean 6.5, SD 0.35), and 2 samples per plot for the the remaining 3 new intervention plots (mean 6.5, SD 0.16)), with no pH measures below 5.8, and most measures between 6.3 and 6.8.
Sweet corn and 4 legumes had been planted in the new intervention and control fields and collected and dried for analysis, but given the tilling problems and fluctuating pH data, a late crop of corn was planted in 4 of the older plots, where rye had grown well and the soil conditions are likely more stable and the amendments better mixed. It is now tasseled and I expect to harvest ears before first frost. Among the 4 legumes, cowpeas had done very well and were planted in the remaining 2 old plots where rye had grown.
Analyzable data have been collected for 2018 amaranth crops and 2019 winter rye. Over 100 five-gram samples of a wide variety of crops have been collected for mineral analysis by the Ohio State University STAR lab, and will be submitted when the remaining samples are collected. A large amount of okra and pumpkin fruit have been collected for analysis. Amaranth and sunflowers also were planted late and have not yet been harvested, but are producing seeds now.
The results of 2018 amaranth and 2019 rye are summarized in the attached pdf file, which is a poster that was presented at the 2019 FMX conference in Philadelphia, arranged by the American Academy of Family Physicians (AAFP). The poster illustrates that soil nutrients like Mg++ and Zn++ are preferred divalent cations for many steps in the synthesis of vitamins related to type II diabetes, but that there are often alternative cations that work to some degree. The poster further illustrates that amaranth grown in the intervention soil had higher concentrations (lower calories per mg of nutrient) of Mg++ and Zn++, and lower concentrations of Cu++ and Zn++, compared to the control field. Vitamin synthesis was not different. Rye showed similar but not statistically different trends. While these initial results do not suggest a clinically important difference in nutritional value, and the differences may be more obvious in mineral content than vitamin content, there can be some effect from soil chemistry on nutrient density.
Educational & Outreach Activities
The attached poster presented amaranth and rye results, and explained the relevance of soil health to type II diabetes to family physicians attending a national educational conference.