Biochar As A Soil Amendment

Hailin Zhang

Dept. of Plant and Soil Sciences Oklahoma State University

What Is Biochar?

Biochar refers to charcoal when it is used as a soil amendment Biochar is created by pyrolysis of

biomass (burning biomass under controlled low-oxygen conditions, a technology advanced from smoldering)

Why Use Biochar as a Soil Amendment?

Biochar is a trendy yet ancient soil amendment Study of biochar-rich dark earth in the

Amazon (terra preta) leads to wilder appreciation The “dark earth” stands out against the

surrounding areas Carbon dated at least 1,500 yr. old

Biochar produce energy, sequester C and improves soil

Phlush.org

How is Biochar Made?

Sonomacompost.com

Biochar is available in all sizes and shapes

Vuthisa.com

sunmarkenvironmental

Composition of Biochar

Feedstock Temp SSA (m2/g) % C % H % N % O % Moist % Ash Corn cob 250 OC 1.86 61 4.96 0.82 27.8 1.32 3.92 Corn cob 300 OC 2.42 71 4.19 0.81 19.1 1.3 4.1 Corn cob 350 OC 3.36 73 3.79 0.79 16.9 1.29 4.35 Corn cob 400 OC 4.70 75 3.37 0.82 14.1 1.35 5.12 Corn cob 450 OC 7.79 78 2.95 0.86 11.4 1.35 5.55 Corn cob 500 OC 17.1 81 2.5 0.97 8.87 1.25 5.56 Corn cob 550 OC 30.6 83 2.25 0.84 7.43 1.28 5.58 Wood pel 750 OC 105 82 1.14 0.52 3.04 4.56 8.75 Wood chip 450 OC 12.9 70 2.67 1.11 13.9 1.69 10.2 DDG 400 OC 1.98 64 3.76 7.44 10.1 1.45 12.8 Corn stov 400 OC 4.69 56 3.4 0.43 18.2 1.28 20.8 Pine cone 400 OC 17.9 74 3.21 1.33 15.3 1.32 4.95

High Surface Area of Biochar

http://globalwarming-arclein.blogspot.com

Benefits of Biochar

Biochar makes plants grow well Raises soil pH Provides and holds nutrients Holds more water Hosts more beneficial microorganisms Encourages greater root development

Biochar promotes plant growth

Biochar.org

Biochar increased corn yields

Benefits of Biochar

Biochar is extremely stable, persisting for hundreds if not thousands of years Takes more carbon out of

atmosphere than it releases (C negative)

Offers potential carbon credits

Benefits of Biochar

Biochar amendment is good for the environment Reduces water pollution Minimizes soil degradation Decreases emissions of nitrous oxide

as well as methane

Energy

Can we afford using biochar?

Black Owl Biochar, $12.5/10 oz, $40,000/ton Williams-Sonoma, $12.95/12 oz Phoenix Energy, $253.81/140 lbs.,

$3625.86/ton eBay, $33/40 lbs, $1650/ton

How to Apply Biochar?

It is light, dusty Consider wind

and water erosion during and after application

How to Apply Biochar?

Most studies so far have been small scale Broadcast and

incorporate

How to Apply Biochar?

Subsurface banding will reduce some problems if it works

How to Apply Biochar?

Direct surface application to vegetable crops

Best Management Practices

Apply biochar under the right weather conditions; Apply moisture to biochar; Mix biochar with other amendments

such as manure or compost, and clay Pelletizing biochar

Other uses of biochar

Contaminants retention Land reclamation Mixed in compost to retain

nutrients, and moisture

Summary

Biochar is considered a very beneficial soil amendment It is currently expensive and the real

economical benefits remain to be discovered for agriculture The low density makes it challenge to

apply in a large scale Some BMPs need to be used