|Start:||1 February 2021|
|Aim:||To contribute to an alignment of research strategies connecting agricultural management, soil quality and climate adaptation potential through its summary of the literature, its meta-analysis and its identification of knowledge gaps.|
|Keywords:||Climate change adaptation, soil management, soil structure, soil organic carbon, soil hydraulic properties, soil-plant interactions, pCO2, soil life|
Project coordinator: Sarah Garre (firstname.lastname@example.org)
Project communication representative: Louise Pauwels (Louise.Pauwels@ilvo.vlaanderen.be)
Year-round soil cover, organic matter additions and a reduction of traffic on agricultural land: Are these management practices to restore and strengthen Europe’s soils? No single management practice can be the one solution for all soils and climates: context is key!
Throughout the EU, farmers, industry and governments are dealing with the impacts of climate change on agriculture. Although the importance of soil in agricultural production is clear, the role of the soil management in climate change adaptation has not received much attention within policy and farmers’ practices. The EJP SOIL CLIMASOMA project synthesized the results of 36 meta-analyses summarizing research from the past 100 years. As such, CLIMASOMA studied the impact of soil and crop management practices on climate change adaptation with a specific focus on soil hydrological functioning. Within the CLIMASOMA project, 36 meta-analyses, bringing together a total of 2803 studies, covering over 10,000 observations, were synthesized and analyzed. All these studies investigated the influence of soil and crop management on climate adaptation, with a focus on soil hydrological functioning. The main conclusions are:
But also: No single management practice can be seen as the one solution for all soils and climates: context is key!
Keeping the soil continuously covered with living plants stimulates soil life and carbon storage. Both are essential in developing a good soil structure, which in turn ensures good water infiltration and storage. This soil cover can be achieved in different ways: catch crops such as rapeseed or phacelia can offer solace in wintertime, grass can be sown under in corn fields and grass strips planted between rows of fruit trees. All agricultural practices come with their own advantages and disadvantages. These plants will take up water as well, which can be a problem in regions that struggle with year-round drought.
Experiments focusing on reduced or no-tillage farming have been conducted for many years. Still, the results of those experiments have been mixed. Where water availability seems to improve, soil compaction increases. Effects of reduced tillage on water infiltration and runoff are ambiguous. In addition, tillage reduction also increases the presence of weeds, which in reality usually results in increased usage of herbicides by those farmers that decide to leave the plow for what it is from time to time. However, reducing soil compaction does have clear positive effects. Rather than installing tillage bans, we might want to evolve more to less, well-timed and lighter machining on the land in general – and to a restoration of compacted soils in the process.
According to a small number of studies, organic carbon is like the mortar in the house of soil. It holds soil particles together and improves soil structure. The research on what farmers can ideally add to their soils to improve structure is often interwoven with questions about other practices, like tillage reduction. Singling out the effects of adding organic material from the effects of tillage is difficult in such studies. Still, the benefits of organic additions such as plant residues, compost, manure, wood chips and biochar cannot be denied. The local availability of this material, preferably in large quantities, remains the big challenge here.
Scientists are fascinated by one material specifically: biochar. It is the charcoal that is created from burning plant material at high temperatures without oxygen. This charcoal is very stable and can exist for years in the soil, which is not the case for other plant materials. Despite scientists’ great excitement for this stable good, farmers are not sharing in the enthusiasm so far. Use of biochar remains limited, showing once again that practical implementation of farming practices takes more than delivering scientific evidence. Practices need to fit into the daily operating of the farm, and the economical and legislative framework and scientific knowledge need to reach the farmer.
Even though some practices clearly showed up as beneficial, the main takeaway remains that farming is very context-specific. No single practice is ideal in all combinations of soil, climate and crops and no single practice can be seen unattached to the entire context of the agro-ecosystem it exists in. No matter how much organic material you add to the soil, there won’t be much effect if you proceed to destroy your soil structure by driving over it with heavy machinery while it’s wet. Thus, we need to stay away from generalizations and keep investigating how those context-specific relations between farming practices and water-regulating soil functions can be understood.
The CLIMASOMA project partners created two policy briefs to convince policymakers of the importance of their findings and guide them in the implementation:
CLIMAte change adaptation through SOil and crop MAnagement: synthesis and ways forward
Soil management and cropping systems to enhance soil quality are often proposed as a key way to support the sustainable adaptation of EU agriculture to climate change. Many long term field trials quantified the impact of specific management practices on soil quality and crop performance.
However, the data gathered there has not yet been sufficiently synthesized so that practitioners and policy-makers can draw quantitative and context-specific conclusions concerning the efficacy of management practices as climate adaptation tools.
CLIMASOMA will directly contribute to an alignment of research strategies connecting agricultural management, soil quality and climate adaptation potential through its summary of the literature, its meta-analysis and its identification of knowledge gaps.
The above figure illustrates the complexity of drivers, agents and processes governing the dynamics of soil structure and its effects on the soil-plant-atmosphere system that CLIMASOMA is investigating.
Responsible person from organization: Sarah Garré
Swedish University of Agricultural Sciences, Sweden (SLU)
Responsible person from organization: Nicholas Jarvis
Agroscope, Switzerland (AGS)
Responsible person from organization: John Koestel
Council for Agricultural Research and Economics, Italy (CREA)
Responsible person from organization: Claudia Di Bene
Wageningen University & Research, The Nederlands (WR)
Responsible person from organization: Jan Hassink