Using Biochar to Save Water in California Agriculture

sitenum=379

All things biochar: production, gh gases, soil, crops, water, etc.

Author: Elizabeth Crutchfield

Published on: June 27, 2017

The California Department of Water Resources (DWR) is working to increase agricultural water use efficiency here in California. DWR is funding our research on the effect of biochar and compost on crop water usage. We have set up three research sites:

The first is at the Desert Research and Extension Center in Holtville, CA. Biochar from Cool Planet was applied at different rates. The field is currently laying fallow for the summer but sugar beets will be planted in a few months.

The second site is at Monterey Pacific in King City, CA. Biochar from Pacific Biochar was applied with compost then planted as a Pinot Noir vineyard.

The last is Terra Nova Ranch in Helm, CA. Biochar from Pacific Biochar and chicken litter were applied. Processing tomatoes are planted in this field. Watermark Sensors from Irrometer were installed at 1 and 2 foot depths in each of the plots.

Biochar being applied at Monterey Pacific.

Comments: 2

Comments:

by David Dzwilewski

on June 28, 2017 at 8:48 AM

water retention isn't water savings. Plants still have a water requirement and bio char doesn't change that. All organics help with water retention. There are a number of peer reviewed studies and few which I have posted to this blog that indicate that bio char does not significantly affect water retention. Bio Char is a good carbon source but a expensive one. Get away from the water saving claims. Bio char has other values. The water saving claims cannot be supported. There are printed promotional handouts for Cool Terra that claim a 55% water savings. Totally unsupportable. I'll bet that most lower cost organic sources such as greenwaste has a similar value in water retention when compared to bio char.

Reply by Milton E McGiffen

on June 28, 2017 at 9:49 AM

David:
A great point, and one that comes up all the time.

In theory, if you precisely match the water in the soil with the needs of the plant, no soil amendment will every affect water savings. In other words, if you could precisely monitor soil and plant and give the plant what it needs when it needs it, it matters not whether the plant is in sand or clay soil with or without amendment.

BUT: There stories and publications of biochar (and other soil amendments) saving water are persistent. It is possible that it would save water because your irrigation methods are not efficient, or the biochar triggered drought tolerance in the plant or the biochar caused soil microbes to produce compounds similar to hormones ( which can happen).

We are doing the experiment with really good irrigation monitoring technology and will measure both the soil water content and crop yield and other responses. This should prove whether these biochars actually make crops more water efficient or not.