Biochar Interactive Effects with

Potting Mixture & Biostimulant

on Soil Properties and Bean

Growth

Marc-Ari Weekes, Jeff Chandler and Francis Lopez

Department Of Biological & Chemical Sciences

The University Of The West Indies, Cave Hill, Barbados

Effects of Biochar on Soil

Increases Surface Area and

Porosity:

Water Retention

Soil Aeration

Nutrient Retention

Liming Effect

Rhizobial Activity

Verheijen, et al. (2010)

Retrieved from: http://1.bp.blogspot.com/-gBIa_x-

ZszI/UnT__F2QqtI/AAAAAAAADiQ/xZakqm3C2jg/s1600/

SEM+2.jpg

Objectives

Investigate interactions between biochar, potting media texture and biostimulant application in a legume crop

Test Crop: Bean (Phaseolus vulgaris, ‘Green Crop’)

Biochar prepared from Leucaena leucocephala wood feedstock using low-tech drum technology

Hypotheses:

Biochar will be more beneficial in sandy soils due to effects on water and nutrient retention

Biochar + Biostimulant will have synergistic effects on plant growth

Biochar will have beneficial effects on nodulation and nitrogen fixation

Methods

Potted bean plants in 4L pots

Independent Variables: Sand/clay soil Ratio (25%, 50%, 75% sand)

Biochar (Absent/Present) - Leucaena leucocephala biochar (<2mm) – 10% v/v

Biostimulant (Absent/Present) - EM1, Bio-Logic Manufacturing, Barbados - 50 mL/L weekly application

Randomized Block Design – 4 Reps Low fertilizer level applied weekly to all

pots (0.35 g/L, 24:8:16, Scotts Miracle-Gro)

Biochar and soil texture (sand %)

interaction on Soil Moisture

Pod dry mass yield

1

2

3

4

20 40 60 80

Pod y

ield

g/pla

nt

Soil texture (% sand)

b b

a

0

1

2

3

Absent Present

Pod y

ield

g/pla

nt

Biochar

a a

Effect of Biochar and soil texture

(sand %) on Harvest Index

Pod yield was not significantly affected by biochar

Effect of Biochar and Sand %

interaction on Nodulation

Chi-square test of association, p < 0.01

Effect of Biochar and Biostimulant

interaction on Nodulation

Chi-square test of association, p < 0.01

Conclusion

Pod yield was not significantly affected by biochar with or without biostimulant

Biochar can ameliorate negative effects of sandy soil on soil moisture

Positive effects of biochar observed on the number of root nodules

but nodules appeared to be non-effective

Biostimulant increased the number of root nodules in absence of biochar