5 March 2021

More fertility, less emissions. A new project will identify the best mix for soil and climate


The SOMMIT project carried out by CREA under the European Joint Soil Programme is now underway. The goal? Finding the best trade-off between fertility, carbon sequestration and greenhouse gas emissions. In order to provide successful solutions for the whole continent

by Matteo Cavallito


Identify the best solutions to improve soil fertility while reducing greenhouse gas emissions. That’ s the goal of the SOMMIT project, launched by CREA, the Research Council for Agriculture and Agrarian Economy of the Italian Ministry of Agriculture, and funded by the European Joint Programme EJP-Soil, the continental initiative that involves 13 institutions from 9 different countries. The research aims to study the interaction between agricultural strategies and the trade-off between carbon sequestration and gas outflow. These two dynamics are closely linked and lead to different results. With clear consequences for the climate.

Soil properties are crucial

Adding organic matter to the soil is recognized as a key component of circular bioeconomy strategies. Products such as compost or livestock waste may increase fertility and carbon sequestration. But retention levels and emissions volumes are not easy to track since so many different factors are involved. “Soil is a complex system in which pedological factors – which identify the chemical and physical properties of the soil – and climatic factors work together”, says Alessandra Lagomarsino, a research scientist at CREA Agriculture and Environment and coordinator of the SOMMIT Project. “In addition, there are the different effects associated with the specific kind of crop in the soil is and the different properties of organic inputs“. All these issues need to be taken into account. Especially when considering the well-known collateral impacts.

Balancing key factors to cut emissions

Organic matter added to the soil promotes carbon storage but, in some cases, can contribute to greenhouse gas emissions by contrast. “Livestock waste, for example, generates an augmented release of nitrous oxide gas whose warming potential is nearly 300 times higher than CO2″, says Lagomarsino. But these trends are not equal everywhere because of soils different properties. “A Mediterranean loamy soil, for example, performs differently from a sandy one in Central Europe”, adds the researcher. The ultimate goal of the investigation, then, is to identify the most suitable practices to achieve the best possible trade-off. “That is, to increase CO2 sequestration without boosting nitrous oxide emissions too much”.

Three different approaches

The study is based on three different approaches. Researchers will start by using existing data made available by other surveys. A meta-analysis will be conducted on sequestration/emission trade-offs. This subject is still little studied, although it was recently investigated in an interesting paper by Bertrand Guenet, researcher at the Laboratory of Climate and Environmental Sciences of Gif-sur-Yvette (France), published last September. Moreover, researchers will examine the results of some experimental tests carried out in seven different sites which have been under observation for decades, which is an ideal timeframe to assess the variations in capture and release of greenhouse gases “can be seen only in the long term”.

Finally, the investigation will include a modeling approach, in order to predict impacts and solutions for different soils under different chemical, physical and climatic conditions. The integrated study of all these issues will therefore allow to bring solutions to all the actors involved in soil management. From farmers to civil society and consumers.