Work in progress – expect frequent updates to this page!
(Reminder of our Mission) The Food/Soil survey serves to:
- Identify the amount of variation in nutrition in the food supply
- Attempt to relate nutritional data to field-measurable spectral data
- Create a data pipeline that BFA members and partners can utilize to answer questions of interest.
The 2019 Food/Soil survey will target 3000 – 4000 samples, 6 produce types (carrots, spinach, lettuce, kale, cherry tomatoes, and grapes), and roughly 30% of samples direct from farms with associated soil samples. All samples will also have reflectance measurements from 350nm to 2100nm to attempt to calibrate the lab data with the spectral data. Institutional and individual partners this year include Boulder-based Ecocycle, Leandro Mastrontonio of the National University of Cuyo, Argentina, the Foundation for Food and Agriculture (FFAR), and BFA member Faith Reeves.
Improvements in 2019
Based on what was learned in the 2018 Food/Soil Survey (see Final Report for details), the 2019 Survey preparation and implementation has made several key improvements:
- Expanded crops list from 2 (carrots, spinach) in 2018 to 6 (carrots, spinach, kale, lettuce, cherry tomatoes, and grapes) in 2019
- Targeting 600 – 900 samples per crop rather than 200 – 400 samples in 2018. Those targets were derived from ‘best guess’ estimates of what was needed to show effective reflectance calibrations.
- Analyzed, identified, and addressed major sources of noise in our lab processes to improve statistical significance. Includes updating our intake process to use a sonicator rather than mortar and pestle, making more consistent sample stay times in freezer / fridge, improving shipping procedures, etc.
- Eliminated unnecessary tests like proteins, added new tests including pH for soils and Brix for produce
- Significantly expanded reflectance wavelength range (now 350 – 2100nm) and # of instruments used to measure that range (devices from 4 separate companies) to provide added assurance of the spectral results.
- Estimated decrease in costs from $212 per sample to $60 – $100 per sample.
- Added Chico State and Cyndi Daley as a second ‘West Coast’ lab to handle samples coming from California, to test our ability to replicate the process and reduce shipping times for west coast samples.
- Learned lessons from 2018 Data Partners to improve support for Data Partners and create more realistic sampling expectations (down from 2-3 sampling locations per week to 1 location per week).
- Added Farm Partners program (currently at 45 participants) to track weekly, detailed farm-level management information to improve our ability to associate farm practice with nutritional outcomes.
Data collected in the field (sample intake data)
Once samples are collected, data is shipped using standard USPS Priority Legal sized envelopes (ships 1 – 3 days), designed to contain 6 samples (one sample includes both food and soil at 0 – 4” and 4 – 8”) each. Those boxes are shipped to data collectors with pre-addressed and pre-paid return labels, and samples are expected to be returned to the lab the same day they were collected. This minimizes reduction in quality like antioxidents and other compounds which are known to decrease quickly after harvest.
Data and Farm Partners will fill out a web-based survey using the Real Food Campaign Collect app on their Android device when collecting the sample and submit it electronically. That will be connected with the lab data to provide a full accounting of the sample.
All surveys are built using the ODK Build (build.opendatakit.org, or open using OpenOffice or Excel), and resulting data uploaded to app.our-sci.net. The surveys are occasionally updated, and below are links to the most recent versions.
To see detailed descriptions of the testing methods, see the Testing Page.
Data Partners and Farm Partners collect samples from all over the continental US and Canada. One packet (6 samples of produce/soil) are expected per week for Data Partners, while 16 – 24 samples total are expected from Farm Partners throughout the season. Farm Partner are also expected to fill out weekly farm management surveys on the crops they will be sending biological samples to the lab.
For all Partners, weekly sampling recommendations are sent to help improve variety in sampling.