9 March 2021

What is healthy soil? FAO coins the official definition


The UN Agency’s Intergovernmental Technical Group on Soils (ITPS) has defined healthy soil as “the ability to sustain productivity, diversity and environmental services of terrestrial ecosystems”. A starting point for setting comparable indicators on sustainable land management

by Emanuele Isonio


The paradox was becoming more and more evident. The issue of soil health is in fact gaining increasing attention both at the governmental and at the media level. Although there has also been a World Soil Day since 2014, there was still no shared definition of “healthy soil”. The Intergovernmental Technical Panel on Soils (ITPS) of FAO Global Soil Partnership has filled that void. It defines soil health as “the ability of the soil to sustain the productivity, diversity, and environmental services of terrestrial ecosystems”.

The Intergovernmental Technical Panel on Soils (ITPS) is composed of 27 top soil experts representing all the regions of the world. ITPS members have a 3-year mandate and provide scientific and technical advice and guidance on global soil issues to the Global Soil Partnership primarily and to specific requests submitted by global or regional institutions.

Not having an official definition causes risks

“It may seem minor but the ITPS decision is very important,” Giuseppe Corti, president of the Italian Society of Pedology observes. “Not having an official definition of healthy soil has led, in many cases, to consider as useful and healthy that soil and agricultural activity, if it implies the maximization of productions. Instead, we need to develop agricultural systems that provide productions of excellent quantity and quality, respecting the life of the soil (biodiversity) and making sure that its other fundamental functions are also maintained. For example: water purification, reduction of the risk of flooding, mitigation of climate change and the proliferation of pathogens”.

According to ITPS experts, one of the complexities in defining soil health is the lack of agreement on indicators and threshold values ​​due to the singularities and high spatial variability of global soils. Early definitions of healthy soils are rather anthropocentric and focus on soils in agro-ecosystems, especially in last decades. That is, they focused on soils in agricultural ecosystems or for their ability to support adequate biomass production for human needs. In this way, those definitions underestimate the other fundamental ecosystem services guaranteed by soils, such as climate regulation and biodiversity conservation.

Moreover, the absence of a clear definition of healthy soil complicated the work of researchers: “The language of science is and must be universal,” Claudio Ciavatta, professor of Agricultural Chemistry at the University of Bologna explains. “An experiment must be able to be reproduced by other scientists in any other place on the planet. To guarantee this basic principle, it is necessary to share what is needed to achieve the goal: definitions, experimental protocols. The first step could only be to arrive at an unambiguous shared definition of “Soil health”.

Next step: universal indicators for soil health

The ITPS decision attempts to solve precisely this problem: “As with human health, there is no single measure that captures all aspect of soil health. The preservation of these soil services requires avoiding and / or combating all types of soil degradation” FAO experts said.

The official definition of “healthy soil” is therefore the first step to avoid that the same term ends up indicating very different things. “The ITPS coins this definition of soil health and hopes to be widely used and adopted by international organizations, institutions, governments and academia”. Consequently, the ITPS and the Global Soil Partnership are working on the selection of indicators and harmonized laboratory methodologies that are applicable in all countries and enable the assessment, promotion, conservation and restoration of soil health.

Their wish is widely shared by the scientific community. “That definition was absolutely necessary because it delimits the field in which the term ‘soil health’ is declined, a dynamic concept, but with solid pillars described in the definition itself” Ciavatta says. “It is a sort of framework within which all operators recognize themselves and must operate. The definition is fundamental for planning future activities aimed at selecting indicators and analytical methodologies to be used globally.”

“The definition of healthy soils they’ve given actually offers significant benefits,” Corti adds. “If states and especially operators accept it, we can really get on the path to no longer degrading soils. Indeed, we will be able to reclaim degraded ones, leaving future generations with a better quality of life than those who came before them”.

The launch of the Protocol for sustainable management

The experts of the Global Soil Partnership are already working on this further step. At the beginning of the year they published a protocol intended for both farmers and public administrators to clarify the best techniques for having healthy soils. The aim is to assess whether a certain practice is in line with sustainable soil management or if it needs to be rethought. The full version of the protocol is expected to arrive by mid-2021. Preliminary protocol contains 4 core and 10 additional indicators. The main indicators include the productivity of the soil, the level of organic carbon of the soil, its physical properties and its biological activity.