Impact assessment is a method “to structure the analysis of human-environment interactions” (Helming and Pérez-Soba, 2011). It synthesises scientific knowledge to inform policy and management (Carpenter et al., 2006). The knowledge gained by impact assessment supports stakeholders in various areas of decision-making, such as soil management (de Olde et al., 2016), governance and policy formulation (Podhora et al., 2013), or research design for sustainable development (Bond et al., 2012).

Impact assessment prepares evidence on the advantages and disadvantages of possible management or policy options by assessing their potential impacts on intended and unintended, short-term and long-term issues relevant for society (SEC, 2009; Helming et al. 2013). Impact assessment in the context of natural resource use requires the definition of the activities and the environmental and societal system components that are evaluated.

Impact assessment in the context of soil management is crucial in order to recognise the potential consequences of management decisions on social and natural systems across spatial and temporal scales. The assessment evaluates and compares the consequences of different soil management options. This includes management options suggested from a scientific perspective (e.g. fertilisation schemes, tillage technologies, bio-control and microorganism utilization, crop rotations and catch cropping, application of sensor technologies, irrigation), those stemming from bioeconomic innovations (e.g. new cultivars and harvesting technologies, on-site harvest processing) and those derived from policy implementation at local, national and international levels (e.g. greening measures, carbon certificates). The latter category is particularly important because agricultural policies defined at the European level (CAP) and international conventions, such as those for combating desertification (UNCCD), have implications for domestic production (e.g. reduction of protein imports). Likewise, domestic decisions on land management (e.g. renewable energy strategies) may have sustainability implications in other world regions due to global market adjustments (discussed in section IV.2).

Assessments include issues of social acceptance, risk perception, economic costs and benefits, as well as environmental impacts beyond the soil system such as the interaction with water, air, climate and biodiversity. In order to structure different assessment approaches and utilize them for evaluating options in the context of creating a sustainable bioeconomy, we developed the BonaRes Assessment Framework, the BonaRes Assessment Platform (www.bonares.de/sustainability) and the Handbook of Soil-Related Impact Assessment. These products provide a systematic approach to assessing impacts of soil management on societal targets.

Assessment results can be used to inform stakeholders and facilitate a better alignment of human-nature interactions with societal goals, such as efficient use of natural resources or sustainable development (Helming and Pérez-Soba, 2011). Stakeholders include:

a) Policy makers that require assessments of current and future states of all soil functions and services, as well as tools to anticipate future driving forces and trends in soil management.

b) Biomass producers (farmers) that require site-specific information to develop optimal management solutions for tillage, fertilisation, pest management, crop rotations, cultivar selection, and soil conservation. Information needs of this group are at the highest spatial (field) and temporal (up to days) resolution.

c) The biomass processing sector that requires information on biomass quantities and qualities that can be made available at specific locations and points in time, including agricultural commodities and side products such as straw and residues.

d) The wider research community that requires information on soil related impacts and interdisciplinary linkages for their research (e.g. agriculture, hydrology, biodiversity, ecosystem services, climate modelling).

e) Civil Society and their institutions, which are concerned with effects of soil management on the environment and on human well-being.

For soil related impact assessment, we use a set of six steps based on the DPSIR framework (see info-box in the following section). These steps can be seen as a dynamic process studying the societal reaction towards pressures on natural and human systems. It investigates a continuous loop of human-nature-human interactions. We put particular emphasis on the analytical step 4, the assessment step in the narrow sense, which evaluates the consequences of human activities on social and ecological systems from the perspective of societal targets, thereby taking an anthropocentric viewpoint.

Figure 1:

Figure 1: Steps of impact assessment (SEC, 2009; Helming et al., 2013) applied to soil management (Helming et al., 2018)

The six steps of impact assessment link the socio-economic system of societal target setting and decision-making with the natural system of biological, physical, and chemical process interactions (Fig.1). Adapted to soil research, the steps include:

(1) Analysis of future trends and driving forces for soil management options and identification of problems.

(2) Definition of human activities and options regarding soil management practices exerting pressures on soil systems.

(3) Analysis of the effects of human activities on the state of soil processes and soil functions. This analytical step concerns the soil system and depicts how soil processes are affected by soil management, and how this in turn affects the ensemble of soil functions.

(4) Assessment and valuation of direct and indirect impacts of soil management in the context of social, economic and environmental targets.

(5) Comparing the impact of different options, analysing co-benefits and trade-offs. At this stage, case-specific priorities can be assigned to the different impact areas, enabling a ranking of the analysed options.

(6) Recommendations for assessment indicators, monitoring procedures and the evaluation of policy implementation (Helming et al., 2013; Helming et al., 2018).

Impact assessment of soil management practices under the perspectives of resource use efficiency and maintenance of ecosystem services is an emerging field of research that will be highlighted on the in this platform and on the BonaRes Assessment Platform. The limited number of examples found in current literature have a predominantly economic focus (Speiser et al., 2013; Peters et al., 2011). Assessments considering societal decision-making, e.g., by farmers, represent a substantial research gap with the exception of a few studies e.g., in Europe (Giupponi & Rosato, 1999) and in developing countries (Tittonell et al., 2015; Wanyama et al., 2010).

Bond A, Pope J. 2012. The state of the art of impact assessment in 2012. Impact Assessment and Project Appraisal 30: 1-4. DOI:10.1080/14615517.2012.669140

Carpenter SR, Bennett EM, Peterson GD. 2006. Editorial: Special Feature on Scenarios for Ecosystem Services. Ecology and Society 11. DOI:10.5751/ES-01609-110232

De Olde EM, Oudshoorn FW, Sørensen CAG, Bokkers EAM, de Boer IJM. 2016. Assessing sustainability at farm-level: Lessons learned from a comparison of tools in practice. Ecological Indicators 66: 391-404. DOI:10.1016/j.ecolind.2016.01.047

Giupponi R, Rosato P. 1999. Agricultural land use changes and water quality: A case study in the watershed of the Lagoon of Venice. Water Science and Technology 39(3): 135-148. DOI:10.1016/S0273-1223(99)00045-1

Helming, K, Pérez-Soba, M. 2011. Landscape scenarios and multifunctionality: making land use impact assessment operational. Ecology and Society 16(1): 50. Online: https://bit.ly/2YBjAcX (accessed 09 August 2019)

Helming, K, Diehl, K, Geneletti, D, Wiggering, H. 2013. Mainstreaming ecosystem services in European policy impact assessment. Environmental Impact Assessment Review 40: 82-87. DOI:10.1016/j.eiar.2013.01.004

Helming, K, Daedlow, K, Paul, C, Techen, A, Bartke, S, Bartkowski, B, Kaiser, DB, Wollschläger, U, Vogel, H-J. 2018. Managing soil functions for a sustainable bioeconomy – assessment framework and state of the art. Land Degradation and Development 29:3112–3126. DOI:10.1002/ldr.3066

Peters, GM, Wiedemann, S, Rowley, HV, Tucker, R, Feitz, AJ, Schulz, M. 2011. Assessing agricultural soil acidification and nutrient management in life cycle assessment. International Journal of Life Cycle Assessment 16(5): 431-441. DOI:10.1007/s11367-011-0279-5

Podhora, A, Helming, K, Adenäuer, L, Heckelei, T, Kautto, P, Reidsma, P, Rennings, K, Turnpenny, J, Jansen, J. 2013. The policy-relevancy of impact assessment tools: Evaluating nine years of European research funding. Environmental Science & Policy 31: 85-95. DOI:10.1016/j.envsci.2013.03.002

SEC – Secretariat-General European Commission, 2009. Impact Assessment Guidelines. Brussels.

Speiser, B, Stolze, M, Oehen, B, Gessler, C, Weibel, FP, Kilchenman, A, Widmer, A, Charles, R, Lang, A, Stamm, C, Triloff, P, Tamm, L. 2013. Sustainability assessment of GM crops in a Swiss agricultural context. Agronomy for Sustainable Development 33(1):21-61. DOI:10.1007/s13593-012-0088-7

Tittonell, P, Gerard, B, Erenstein, O. 2015. Tradeoffs around crop residue biomass in smallholder crop-livestock systems – What’s next? Agricultural Systems 134(SI): 119-128. DOI:10.1016/j.agsy.2015.02.003

Wanyama, JM, Nyambati, EM, Mose, LO, Mutoko, CM, Wanyonyi, WM, Wanjekeche, E, Rono, SC. 2010. Assessing impact of soil management technologies on smallholder farmers’ livelihoods in North Western Kenya. African Journal of Agricultural Research 5(21): 2899-2908.