1 February 2022

Grazing land, hidden treasure: “Adaptive grazing management helps climate and soil”

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A research on the interactions between livestock, soil and the carbon cycle was just launched in the US. Francesca Cotrufo (Colorado State University): “We are already working at global scale, market participants have realized the importance of the issue”. Carbon is crucial, “but accurate calculation methodologies are needed”

by Matteo Cavallito

 

Interactions between grazing practices, carbon cycling and soil health are the subject of an international research coordinated by three institutions, including Colorado State University (CSU), that was recently launched in the U.S. The study, co-funded, among others, by the Foundation for Food & Agriculture Research and the Noble Research Institute with a total amount of $19 million, involves several scientists. Francesca Cotrufo, professor of soil ecology at the CSU Department of Soil and Crop Sciences, and co-coordinator of the project, is one of them.

Francesca Cotrufo, Professor of Soil and Crop Sciences, Colorado State University, March 13, 2020

“Adaptive grazing management can contribute a solution against climate change by promoting soil carbon sequestration with a positive impact on land, animal and human health,” explains Cotrufo, who was born in Naples (Italy), where she has been teaching until 2008 before moving to the U.S. The study is therefore focused on grazing land, which is widely distributed all over the world where farmers and ranchers from the United States to Central Asia, from Africa to Latin America are experimenting restoration practices.

Such strategies are extremely important: a study published in the journal Agriculture, Ecosystems & Environment estimated that proper management of these lands could lead to the sequestration of up to 300 million tons of CO2 per year at global level.

Professor Cotrufo, what is the goal of the study?

The project is called “Metrics, Management and Monitoring” because it aims to quantify the metrics of soil health in pastures, to determine how different management practices impact these metrics by continuously monitoring them in the field, and finally to identify the socio-economic factors driving farmers’ management decisions.  More specifically, my role focuses on quantifying soil carbon sequestration in response to changes in pasture management, and developing a predictive model that can be verified by measured data that accurately predicts the impact of changes in pasture management on soil carbon sequestration and greenhouse gas emissions.

So how will this research be carried out?

Scientists, sociologists, and economists will cooperate in this transdisciplinary project. The research will take place at three experimental sites in Michigan, Oklahoma, and Wyoming. Each site will be part of a research “hub” which will also include 20 ranches where we will integrate bio-geochemical and socio-ecological studies. In this way we hope to offer useful information to farmers to make decisions for the sustainable and productive management of their farms, and for the regeneration of the land they work on.

When do you expect to get the results?

The project will run for 5 years. In the first year we will complete soil sampling at all experimental sites and install all sensors and towers for continuous measurement of ecosystem CO2 exchange.  Over the next 3 years we will continue to monitor the experimental areas, sample all farms, and work on developing models. In the fifth year we will re-sample soils in the experimental sites to verify the predictions obtained with the models. Partial results will come during the life of the project, but we will have to wait until the end for the complete data and overall findings.

Campionamento del suolo in pascolo. Foto: courtesy of Francesca Cotrufo

Soil sampling in grazing land. Photo: courtesy of Francesca Cotrufo

What are the limitations of current approaches for calculating soil carbon sequestration?

At the moment they all have major limitations. In my opinion one of them is that they are limited to the measurement of bulk soil organic carbon. The point, however, is that soil organic carbon appears in different forms, either particulate or associated with soil minerals, which determine how it is accrued, but also its sensitivity to land management change and climate change. Thus, in order to accurately predict soil carbon sequestration, we need to use approaches that quantify and model carbon in these two contrasting forms . Some mathematical models have already been designed to better capture this complexity and help us in making decisions.

Adaptive grazing management has been estimated to have great potential to enhance carbon sequestration worldwide. Can we say that studies like yours are attracting growing interest?

Yes, we’re doing a lot of work in the U.S. but also globally with both agriculture and livestock companies and with carbon credit market participants. We try to help them understand that carbon markets need accurate methodologies. And market participants do realize the need to accelerate this transition.

 

Taglio e imbustamento di una carota di suolo appena campionata. Foto: courtesy of Francesca Cotrufo

Cutting and bagging a newly sampled soil core. Photo: courtesy of Francesca Cotrufo

It’s no surprise, then, that the New York Times recently reported on an unprecedented alliance between farmers and conservationists …

In the U.S. crop farming and livestock grazing are very diversified sector with many actors carrying different interests. Regenerative agriculture and adaptive grazing practices are attracting increasing interest, even among young people. Farmers in particular are facing increasing difficulties due to climate change. It is no coincidence that they are the first to realize they need to change their strategies.