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

2. This is where my journey started, at
Rodale’s FST in the Lehigh Valley

3. 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.

4. The Carbon Underground Tropical
Farming Systems Trial
Trial Design

5. Same cassava starter cuttings,
same farmers, same sun, same
starter soil, same water

6. Then a drought happened….

7. The organic cassava

8. The “conventional” cassava

9. 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

10. 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

11. 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.

12. 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.

13. On the left, conventional. On the
right, regenerative organic.

14. Seeking explanations for the
organic success vs. the
conventional failure

15. 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

16. 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

17. Could there be a deeper cause?
Recall that soil organic carbon can
retain up to 40X its weight in
water….

18. So we dug down for information.
More precisely, we took 810 soil
samples down to 80 cm, with 135
samples per farming system

19. And a note on determining carbon
sequestration: we use the The
Earth Partners’ soil carbon
methodology, approved as a
Verified Carbon Standard

20. 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.

21. 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.

22. Let’s look at differing soil depths
to see if we can find out what’s
happening with soil organic
carbon

23. 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

24. 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

25. 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

26. 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

27. 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

28. So let’s focus on the
trends at the 60-80 cm
depth

29. 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

30. 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

31. 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

32. 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.

33. 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!

34. And in every case the Biodynamic
or Organic treatments maintained
their carbon inheritance better
than the conventional practices.

35. 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.

36. 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%

37. 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.

38. Join us!
www.thecarbonunderground.org