The Effects of Biochar Applications on Soil Fertility & Crop Production for a

Small Farm in the Northeast US Ron Poitras & Sue Straubing

Northeast Biochar

SymposiumNovember 13,

2009

Sponsored by Northeast SARE Farmer Grant Program in cooperation with MOFGA

Downeast Maine is 'biochar country'

● Unusual geology● Extensive Low bush

blueberry cultivation● Long tradition of

burning (charring) fields

Research Design● 24 separate plots, (16

test plots, 8 controls), ● 2 amounts of biochar

applied – 0.5lbs/sq ft & 1.5lbs/sq ft

● 3 different types of char used

● 2 crops grown – soybeans & corn

● Confounding factors

Biochar Production

Bruce's Char - # 1

Prototype - horizontal afterburner design, produces biochar, process heat and electricity

Biochar Production (cont'd)

George's Char - # 2 simple two barrel (home oil storage tank + 55 gal drum) burner

Biochar Production (cont'd)

Chip Energy Char # 3● biomass furnace produces

char & heat through pyrolysis, gasification & combustion of the gases

Characteristics of Three Biochars UtilizedBiochar # 1Bruce's char

Biochar #2George's char

Biochar #3Chip Energy char

Characteristics Low (400C) temperature,multi-purpose, backyard energy & char production process

Moderate (500C) temperature, double barrel, backyard production process

High temperature,byproduct of industrial energy production project

Feedstock 70 – 80% hardwood shavings & sawdust

Hardwood pallets charred & chipped

Commercial hardwood pellets

Adsorption Capacity

1.50% 1.30% 2.18%

Adsorption Capacity of various commercial lump cooking charcoals

High moderate low

Comparisons5 - 8%

(ex. Montana & Cowboy charcoal)

1.5 – 2.0%(ex. Average commercial charcoal)

1.0 - 2.0%(ex. Low cost charcoal

with fuel starting additives)

Weight of soybeans harvested - comparison with no char plots: percent difference

Test plots with the highest amount of

char added, produced the highest average weight of soybeans

harvested ).5 char/sq f t 1.5 char/sq f t

-25

-20

-15

-10

-5

0

5

10

15

20

Char # 1Char #2Char # 3Average

0.5 lbs/sq ft

1.5lbs/sq ft

Weight of corn plants harvested - comparison with no char plots: percent difference

Char # 1 increased corn yields while Char # 2 and # 3 of any type or amount negatively affected crop yields

0.5 lbs/sq f t 1.5 lbs/sq f t

-20

-15

-10

-5

0

5

char # 1Char #2Char # 3Average

Soybean leaf brix readings

Brix readings taken in August were highest in the 1.5 char # 3, 1.5 char # 1 and the no char control plots

Brix readings0

1

2

3

4

5

6

7

8

no char plots.05 char # 10.5 char # 20.5 char # 30.5 char av.1.5 Char # 11.5 Char # 21.5 Char # 31.5 char av.

Selected soil characteristics

Soil changes were most affected by initial fertilization (fishmeal, bonemeal, azimite) less so by the biochar

soil PH % organic matter CEC acidity0

5

10

15

20

25

30

35

40

45

50

beginning 5/26/09no char0.5 char # 10.5 char # 20.5 char # 31.5 char # 11.5 char # 21.5 char # 3

Conclusions● In soils that already have a high

organic matter content biochar will show little if any crop yield improvements in the first year

● Biochar applied to cold climate soils takes longer to work

● Biochar performs best in soils that are inefficient in retaining nutrients.

● Size of biochar particles, and how it is produced, affect performance when first applied

● Adsorption capacity of biochar is an important factor in determining how biochar will perform