To view the article abstracts from this months research update follow this link:
FEBRUARY 2018 RESEARCH UPDATE
The Power of Soil Carbon
Many of us who are passionate about biosolids in the good way are so because we
have seen what they can do for plants. Supersize, luxurious growth, incredible vigor
-- name your superlative. Plants respond to biosolids applications by growing like
crazy. It turns out that one of the reasons that the plants like biosolids so much is
because biosolids do wonders for the soil. The primary way that one can improve
soils is to feed them a well-balanced diet, rich in carbon and other nutrients. This
helps soil provide nutrients, hold water, and grow plants. It also helps soils store
Soil carbon storage is a tool for fighting climate change. Soil carbon storage through
use of amendments like composts and biosolids is emerging as a means for
offsetting emission and for increasing resilience to climate changes that are already
occurring. As we continue this path, more and more people are seeing the light and
the mechanisms for the brightness are becoming better understood. This library
focuses on both this increased recognition and the mechanisms that support the
magic. Welcome to the first “biobull” library of 2018.
The first article in the library is an editorial from the New York Times. In it the
author, a writer for the LA Times, talks about how increasing soil carbon storage is a
way to both reduce carbon emissions and keep eating -- not quite having your cake
and eating it too, but pretty close. This is a short, well written piece (Soil power!
The dirty way to a green planet). that details what most of you reading this blurb
likely already know: soil is a critical part of the solution and we are part of the
toolbox that makes it so. I include it here because the article is from the NYT and
provides a short and succinct summary of why land application is terrific. In
addition to a discussion on how to hurt soil and the role of synthetic fertilizer, and a
presentation on the resurgence of regenerative agriculture, the author also talks
about compost addition. He cites the California soil health initiative and the Marin
The Marin Carbon Project is the focus of the second article in the library. What
happened in Marin is that a rancher partnered with a professor at UC Berkeley and
looked at whether compost made from animal manure could help restore
productivity and increase soil carbon in a degraded rangeland. The short answer is
yes. A single application increased soil carbon, water holding capacity and net
primary productivity. That is the research presented in the second paper. This is
stuff you already know if you have worked with biosolids. Point is, they hadn’t
known that fact and they have a great website of their discovery
(http://www.marincarbonproject.org/about). This is a great website for getting
attention paid to what they have done, and they are working to expand the research.
This Marin Carbon paper was written by Rebecca Ryals and Whendee Silver.
Whendee is the professor at UC Berkeley and Rebecca, now at UC Merced, was her
graduate student. Rebecca has started working with SOIL Haiti
(https://www.oursoil.org/who-we- are/about-soil/) and attended the W- 3170
meeting last year. Hopefully soon, with the appropriate partners (hear that CASA?),
she will start working more with biosolids-amended soils.
The 3 rd and 4 th papers in the library delve into the mechanisms behind observed
increases in soil carbon storage. I discussed this topic in previous libraries on this
topic, February 2009 for example. The 3 rd paper describes work done on the WSU
long-term dryland wheat plots. These authors have analyzed the soil carbon and
nitrogen, dividing them into the heavy and light weight fractions. Biosolids
increased both fractions in comparison to both the control and the fertilizer-
amended plots. The largest increase was seen in the light weight fraction, with 91%
of the carbon added in the biosolids application staying in the soil. That is a
remarkably high percentage. Thirty five percent of the added N was also retained.
Yields between the fertilizer and biosolids plots were about the same, but in the
fertilizer plots none of the added N was retained.
The 4 th paper looked at fields in Illinois that had biosolids applied for 13 years, from
1972-1984. Here the authors looked at how much of the crop residue stayed in the
soil. They measured this over 34 years, from 1972- 2006. They found that, with the
balanced nutrition provided by biosolids, soil microbes were able to assimilate more
of the crop residue carbon, retaining 32.5%. In comparison, the fertilized plots only
retained 11.8% of crop residues. Both studies show that biosolids, by providing a
balanced diet, helps soils add carbon over time and simultaneously hold onto
The final paper in the library is also based on data from the long-term biosolids
plots in Illinois. The authors look at both mine sites and degraded farmland and
attempt to develop degradation/soil carbon accumulation rate constants. They note
that the CENTURY model is the gold standard for soil carbon in traditional
agriculture. In this study, they build an equivalent model for biosolids. The model
includes both the added C from biosolids and the added C from increased biomass.
All slopes show a high rate of initial accumulation, followed by a stabilization at the
higher level of soil C. The stabile phase is the result of a combination of biosolids C
breaking down and increased crop residue staying put. While this is based on
conditions in Illinois, the 2 nd and 3 rd papers in the study suggest that similar models
are possible for different organic amendments in different parts of the country and
for different land management scenarios.
The take home is that, more and more, scientific studies are confirming and
explaining the biosolids magic. Adding organics to soil increases soil organic matter
and improves soil for the long-term. This is a powerful tool to combat climate
change and still have supper. SYLVIS, a long-time member of Northwest Biosolids is
developing a new, easy-to- use model to calculate how much carbon your biosolids
can sequester. Even if you don’t have the patience to read the papers, soon you can
just use this calculator.
Sally Brown, University of Washington