Tom Newmark - Field Trials in Costa Rica

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Tom Newmark - Field Trials in Costa Rica
From Biodiversity for a Livable Climate conference: "Restoring Ecosystems to Reverse Global Warming"
Saturday November 22nd, 2014
www.bio4climate.org

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Tom Newmark - Field Trials in Costa Rica

  1. 1. This is where my journey started, at Rodale’s FST in the Lehigh Valley
  2. 2. 40% of the world’s population and 55% of children under the age of 5 live in the tropics. We need to demonstrate that regenerative agricultural practices work in the tropics.
  3. 3. The Carbon Underground Tropical Farming Systems Trial Trial Design
  4. 4. Same cassava starter cuttings, same farmers, same sun, same starter soil, same water
  5. 5. Then a drought happened….
  6. 6. The organic cassava
  7. 7. The “conventional” cassava
  8. 8. Marked Failure to Germinate in Conventional Fields 2500 2000 1500 1000 500 0 BD.A BD.B OR.A OR.B CV.A CV.B Average number plants per treatment group Average number per treatment group that did not germinate
  9. 9. 40.0000 35.0000 30.0000 25.0000 20.0000 15.0000 10.0000 5.0000 0.0000 Average % of plants that did not germinate per treatment group BD.A BD.B OR.A OR.B CV.A CV.B Average % did not germinate per treatment replication set
  10. 10. We then replicated germination conditions in a more controlled environment, taking soil from each of the six farming systems and replicating the drought conditions by planting under greenhouse plastic.
  11. 11. We found that the germination results under greenhouse plastic were the same as in the field. Here are two photos to show the differences between regenerative organic and conventional treatments.
  12. 12. On the left, conventional. On the right, regenerative organic.
  13. 13. Seeking explanations for the organic success vs. the conventional failure
  14. 14. Bacterial Dynamics 14000 12000 10000 8000 6000 4000 2000 0 OR A OR B BD A BD B CV A CV B Average Bacteria Biomass (ug/g) Feb. 2014 Average Bacteria Biomass (ug/g) Apr. 2014
  15. 15. Protozoan Dynamics 100000 90000 80000 70000 60000 50000 40000 30000 20000 10000 0 OR A OR B BD A BD B CV A CV B Average Protozan Population Feb. 2014 Average Protozan Population Apr. 2014
  16. 16. Could there be a deeper cause? Recall that soil organic carbon can retain up to 40X its weight in water….
  17. 17. So we dug down for information. More precisely, we took 810 soil samples down to 80 cm, with 135 samples per farming system
  18. 18. And a note on determining carbon sequestration: we use the The Earth Partners’ soil carbon methodology, approved as a Verified Carbon Standard
  19. 19. And now we have 9 months of data. Remember: the organic farming systems all used compost tea, compost mulch (applied at a rate of approximately 7 tonnes per hectare, of which approximately 2 tonnes is organic C), and only had an initial tilling. The conventional systems used herbicides, pesticides, and had two tillings.
  20. 20. As you’ll see, after the initial tilling, where a decades-old weed mat was ploughed under, we introduced a significant amount of “labile” or unstable carbon over baseline.
  21. 21. Let’s look at differing soil depths to see if we can find out what’s happening with soil organic carbon
  22. 22. COA COB BDA BDB ORA ORB TREATMENT 0-10 kg of C per m² Pre-till 0-10 kg of C per m² Post-till 0-10 kg of C per m² 12 de agosto 78.50 67.29 56.07 44.85 33.63 kg of C per m² 43.77 44.67 42.61 46.54 41.23 48.53 Change in Kg of Carbon per m² at 0-10 cm SOURCE: RAW DATA, TFST TEAM SEPT, 2014 P VALUE = NOT STATISCALLY SIGNIFICANT
  23. 23. COA COB BDA BDB ORA ORB TREATMENT 10-20kg of C per m² Pre-till 10-20 kg of C per Post-till 10-20 kg of C per m² 12 de agosto 57.70 49.80 41.90 34.00 26.10 kg of C per m² 32.57 32.72 36.42 36.95 33.57 36.28 Change in Kg of Carbon per m² at 10-20 cm SOURCE: RAW DATA, TFST TEAM SEPT, 2014 P VALUE = NOT STATISCALLY SIGNIFICANT
  24. 24. COA COB BDA BDB ORA ORB TREATMENT 20-40 kg of C per m² Pre-till 20-40 kg of C per m² Post-till 20-40 kg of C per m² 12 de agosto 68.26 59.09 49.91 40.73 31.55 kg of carbon per m² 47.83 47.42 48.84 47.42 44.75 50.12 Change in Kg of Carbon per m² at 20-40 cm SOURCE: RAW DATA, TFST TEAM SEPT, 2014 P VALUE = NOT STATISCALLY SIGNIFICANT
  25. 25. COA COB BDA BDB ORA ORB TREATMENT 40-60 kg of C per m² Pre-till 40-60 kg of C per m² Post-till 40-60 kg of C per m² 12 de agosto 54.60 45.40 36.21 27.02 17.83 kg of carbon per m² 28.16 30.44 35.13 33.63 38.52 41.13 Change in Kg of Carbon per m² at 40-60 cm SOURCE: RAW DATA, TFST TEAM SEPT, 2014 P VALUE = NOT STATISCALLY SIGNIFICANT
  26. 26. COA COB BDA BDB ORA ORB TREATMENT 60-80 kg of C per m² Pre-till 60-80 kg of C per m² Post-till 60-80 kg of C per m² 12 de agosto 50.45 39.40 28.35 17.30 6.25 kg of carbon per m² 25.90 23.16 25.64 27.15 28.08 38.12 Change in Kg of Carbon per m² at 60-80 cm SOURCE: RAW DATA, TFST TEAM SEPT, 2014 P VALUE = NOT STATISCALLY SIGNIFICANT
  27. 27. So let’s focus on the trends at the 60-80 cm depth
  28. 28. MEDIAN LABILE CARBON ABOVE BASELINE AFTER THE TILLAGE AT A 60-80 CM DEPTH Test:LSD Fisher Alfa=0.05 DMS=11.51007 Error: 41.8608 gl: 12 Treatment Median n E.E. Conv A 13.88 3 3.74 A Conv B 9.85 3 3.74 A B ORG B 8.34 3 3.74 A B ORG A 4.37 3 3.74 A B BD B 1.74 3 3.74 B BD A 0.65 3 3.74 B Medians that share the same letter are not statistically significant (p > 0.05) SOURCE: RAW DATA, TFST TEAM SEPT, 2014 P VALUE = NOT STATISCALLY SIGNIFICANT
  29. 29. MEDIAN CHANGE COMPARED TO POST TILL LEVELS IN CARBON (TONNES PER HECTARE) SIX MONTHS POST TILL AT 60-80 CM DEPTH - Test:LSD Fisher Alfa=0.05 DMS=12.34004 Error: 48.1154 gl: 12 Treatments Median n E.E. ORG B 7.05 3 4.00 A BD B 2.31 3 4.00 A B BD A 0.61 3 4.00 A B C ORG A -2.36 3 4.00 A B C Conv B -8.82 3 4.00 B C Conv A -12.55 3 4.00 C Medians that share the same letters are not statistically significant (p > 0.05) SOURCE: RAW DATA, TFST TEAM SEPT, 2014 P VALUE = NOT STATISCALLY SIGNIFICANT
  30. 30. Sharper focus on Conventional A, where 13.88 tonnes (median) per hectare of carbon were introduced post tillage at a depth of 60-80 cm
  31. 31. Now focus on Conventional A after 9 months of growing cassava – Conventional A lost 12.55 (median) of the additional 13.88 tonnes C per hectare. It spent most of its inheritance.
  32. 32. Let’s focus now on Organic B, where approximately 8 tonnes of C were introduced post initial tilling, and approximately 7 additional tonnes were added over the next nine months. It earned a nice return on its inheritance!
  33. 33. And in every case the Biodynamic or Organic treatments maintained their carbon inheritance better than the conventional practices.
  34. 34. As a result, an “aggregate” look at the test lots, adding up the carbon at all depths, shows how the organic and biodynamic fields were far better at retaining their “inheritance,” in contrast to the conventional lots’ more profligate spending.
  35. 35. Spending the carbon inheritance treatment Mg/ha of C added after tilling Mg/ha of C that was able to retain Mg/ha of C lost % Mg/ha of C lost % Mg/ha of C retain Conventional 43,09 5,56 37,53 87,09% 12,91% Biodynamic 58,21 24,54 33,67 57,84% 42,16% Organic 37,00 15,54 21,46 57,99% 42,01%
  36. 36. These data do not achieve statistical significance with 95% confidence. But they paint a picture of what is happening real time in a field that is transitioning from being overgrazed for 65+ years to productive farming. This transitional moment is of critical importance.
  37. 37. Join us! www.thecarbonunderground.org

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