The Pyramid Scheme of High Organic Amendment Rates

There are many soil health benefits of applying high rates of organic amendments. For example, a recent meta-analysis found adding organic amendments increased soil organic matter across multiple studies by an average of 29% in croplands and 34% in grasslands (Figure 1 below, Beillouin et al., 2023). This is the power of winning a pyramid scheme. What the studies don’t consider, however, is what happens to the losers of a pyramid scheme. What do I mean by all this? With organic amendments, all of it had to grow somewhere.

A pyramid of squares leading to a top winner.

High rate of compost application showed stable yields in dryland wheat systems: a long-term study

Compost is used as a nutrient source as well as soil conditioner with a number of noted benefits in agricultural production systems. Compost application improves soil structure, soil moisture retention and builds up soil organic matter (Doran, 1996). Compost application has also been shown to activate soil microbial communities that help in nutrient cycling. Past studies have reported that compost helps improve soil water infiltration and binds the soil particles, helping reduce erodibility (Nigusse et al., 2015).

A field with exposed soil and compost. A small orange flag is in the corner.

Reflections on 2023

CSANR is an entity not easily explained in one fell swoop, but the range and breadth of projects we’ve undertaken throughout 2023 really showcase our primary goal: to find inspired solutions for the future of agriculture and the environment. Take a minute to reflect with us on 2023 and look forward to the developing projects and partnerships of 2024.

People talking next to fences in a field

Nitrogen Fertilizer and Soil Organic Matter: What Does the Evidence Say?

Does synthetic nitrogen fertilizer burn up soil organic matter? Whether you are focused on soil health, soil sequestration, or soil carbon credits, this is an important question. The persistent claim is that synthetic N fertilizer can “burn” soil carbon by supercharging the soil microbes. This claim mainly arises from a 2007 research article from researchers at the University of Illinois (Khan et al., 2007; open access here) and has recently resurfaced in another article (Jesmin et al., 2021) and the resulting (flawed) media coverage. However, a single study is far from conclusive – so what does the broader scientific literature say? And what have we learned in the last few decades on the relationship between synthetic N and soil organic matter?

Graphic showing proportions of soil organic matter

Putting Numbers to the Difficult Task of Increasing Soil Organic Matter

You may know that it is difficult to increase soil organic matter, but how difficult is it, with numbers? First, your crop harvest removes up to 50% of the biomass grown. Then, about 90% of the remaining crop biomass is decomposed by soil organisms leaving only 10% contributing to soil organic matter.  You also have to account for the annual 1-5% losses of existing soil organic matter. Using these and other estimates, let’s do some rough calculations so you know what to expect. The task is difficult, but the math is easy, I promise.

What it takes to increase soil organic matter from 1% to 1.1% in the top 6”.

Drought Resilience in Dry Land: Plant Auxins and Adaptive Management

Eastern Washington averages over five million acres of farmland dedicated to growing wheat and other rotational grain crops that rely solely on rainfall to water their plants, called dryland systems. Within these dryland systems, there is a wide range of potential precipitation levels. Some regions get as little as 7-9” annually, and in recent years, many are experiencing increased uncertainty in the amounts or timing of that precipitation.  Approaches to drought resilience in wheat, one of Washington’s major commodity crops, include adaptive farm practices and application of biochemical principles.

Eastern Washington state Landscapes and pastures on sunny day

Building the Case for Compost and Carbon Sequestration

In the spirit of “what gets measured gets managed”, there has been recent attention directed to how we can quantify potential benefits of compost as an agricultural soil amendment, and its potential to sequester carbon. Accounting for benefits in a defensible way is one key to creating channels for the most impactful action. The beauty of CSANR often lies in its ability to meet challenges like this where they are, to bring science to bear, and provide pathways forward to sustainable solutions.

bag of food scraps on top of compost

Meeting Food Demand through Agronomic Engineering and Incremental Transformation

In a realistic scenario, where not everyone gives up eating meat, where some in the developing world eat more like us, and where food waste is not zero, feeding 9+ billion people will require a lot more food. Ideally, this additional production would be from existing cropland, with better input efficiency, and fewer off-farm effects. How are we going to do this, both in currently high-yield agriculture and where significant yield-gaps exist? This is the topic of an important book chapter from Hunt, Kirkegaard, Celestina, and Porker (2019): Transformational agronomy: Restoring the role of agronomy in modern agricultural research.

Inforgraphic of agronomy considerations