Monitoring SDG2 with Global Yield Gap Atlas

With the 2030 Agenda and the Sustainable Development Goals (SDG) countries have committed themselves to time-bound targets for Prosperity, People, Planet, Peace, and Partnership. SDG 2 (Zero Hunger) aims to end hunger, achieve food security and improved nutrition, and promote sustainable agriculture. It strives to double the agricultural productivity and incomes of small-scale food producers by 2030 while ensuring sustainable food production systems and resilient agricultural practices.

Figure 1: the 17 SDG themes

The official indicators for SDG 2 show that since 2015, the number of people suffering from hunger has increased, and that stunting and wasting in children are declining but not fast enough. These official indicators for SDG 2 capture various aspects of nutrition but barely any aspects related to agriculture (e.g. productivity, income from farming, resource use efficiency).

SDSN’s SDG Index supplements the official SDG indicators with non-official indicators that are selected using a set of criteria. One indicator for SDG 2 that has been added to this year’s SDG Index, for the moment only for OECD countries, is Yield Gap Closure. It is based on data from the Global Yield Gap Atlas (GYGA) developed by WUR and UNL. Yield gap closure relates a country’s actual yields for its three main crops (in terms of area) to their potential yields. This indicator is a valuable addition to the indicator on actual cereal yield that was used in the SDG Index since its inception.

Figure 2: Concept of yield levels and yield gap (modified from: van Ittersum and Rabbinge, Field Crops Research (1997)

Actual cereal yield alone is too limited to assess agricultural productivity. A maize harvest of 5 ton per hectare in semi-arid regions like Burkina Faso would represent a relatively high productivity because such a yield is close to the potential yield (i.e. a small yield gap). In western Ethiopia, however, a maize harvest of 5 ton per hectare represents a relatively low productivity of rain-fed agriculture as the potential yield is estimated well above 10 ton/ha. So yield gap closure puts actual yield levels into a perspective of what is possible with the current climate and soils. It highlights the depth of the challenge to increase crop production.

SDSN concludes that yield gap closure remains well below the 80% target in numerous OECD countries, and even below 50% in eight OECD countries for which data are available. This reveals the scope for further production increases in different countries, provided this can be combined with resource-use efficiency and environmental indicators. Yield gap closure is never an aim in itself, but only in combination with food security and environmental targets.

Figure 3: Example from SDSN report: how Poland scores on SDG2: zero hunger

GYGA provides robust estimates of untapped crop production potential on existing farmland based on current climate and available soil and water resources. GYGA works country by country and uses local data and expertise. The yield potential is expressed in two ways: assuming full irrigation (Yp) and assuming water available only through precipitation (Yw). Values are determined by applying a standard protocol based on best available local data on weather, crops and soils, based on robust models for assessing potential production, and a bottom-up approach to scale local results to region and country.

Figure 4: GYGA’s upscaling protocol

Besides its specific use by SDSN, results from GYGA can serve for identifying regions with greatest potential for investment in agricultural development and technology transfer and to monitor impact over time. Likewise, GYGA provides essential information to assess the feasibility of a country to achieve food self-sufficiency through crop intensification and, if this cannot be achieved, for assessing how much extra land clearing or food import will be needed to meet future demand for food. GYGA is a foundation for studies aiming to explain and mitigate yield gaps and investigate impact of climate change, land use, and environmental footprint of agriculture. For instance it indicates how much nutrients (organic and/or synthetic) are required to narrow yield gaps following sustainable intensification scenarios and it can be used to assess minimum greenhouse gas emission pathways.

Please have a look at the GYGA portal providing access to all results, underlying data, methods and spin-off studies.

Authors:

Prof. Dr.ir. Martin K. van Ittersum, Plant Production Systems, Wageningen University

Ir. Hendrik L Boogaard, Earth Informatics, Wageningen Environmental Research

References:

Ten Berge H.F.M., R.Hijbeek, M.P.van Loon, J.Rurinda, K.Tesfaye, S.Zingore, P.Craufurd, J.van Heerwaarden, F.Brentrup, J.J.Schröder, H.L.Boogaard, H.L.E.de Groot, M.K.van Ittersum. 2019. Maize crop nutrient input requirements for food security in sub-Saharan Africa. Global Food Security. Vol. 23 (2019), 9-21; https://doi.org/10.1016/j.gfs.2019.02.001.

Van Loon, M.P., Hijbeek, R., ten Berge, H.F., De Sy, V., ten Broeke, G.A., Solomon, D. and van Ittersum, M.K., 2019. Impacts of intensifying or expanding cereal cropping in sub‐Saharan Africa on greenhouse gas emissions and food security. Global Change Biology, 25, 3720-3730; https://doi.org/10.1111/gcb.14783.

Sachs, J., Schmidt-Traub, G., Kroll, C., Lafortune, G., Fuller, G. (2019): Sustainable Development Report 2019. New York: Bertelsmann Stiftung and Sustainable Development Solutions Network (SDSN).

Schils, René L.M., J.E.Olesen, K.C.Kersebaum, B.Rijk, M.Oberforster, V.Kalyada, M.Khitrykau, A.Gobin, H.Kirchev, V.Manolova, I.Manolov, M.Trnka, P.Hlavinka, T.Paluoso, P.Peltonen-Sainio, L.Jauhiainen, J.Lorgeou, H.Marrou, N.Danalatos, S.Archontoulis, N.Fodor, J.Spink, P.P.Roggero, S.Bassu, A.Pulina, T.Seehusen, A.K.Uhlen, K.Żyłowska, A.Nieróbca, J.Kozyra, J.Vasco Silva, B. Martins Maçãs, J.Coutinho, V.Ion, J.Takáč, M. Inés Mínguez, H.Eckersten, L.Levy, J.M.Herrera, J.Hiltbrunner, O.Kryvobok, O.Kryvoshein, R.Sylvester-Bradley, D.Kindred, C.F.E.Topp, H.Boogaard, H.de Groot, J.P.Lesschen, L. van Bussel, J.Wolf, M.Zijlstra, M.P.van Loon, M.K.van Ittersum. 2018. Cereal yield gaps across Europe. European Journal of Agronomy. Vol. 101 (November 2018), 109-120; https://doi.org/10.1016/j.eja.2018.09.003.

Van Ittersum Martin K. , Lenny G. J. van Bussel, Joost Wolf, Patricio Grassini, Justin van Wart, Nicolas Guilpart, Lieven Claessens, Hugo de Groot, Keith Wiebe, Daniel Mason-D'Croz, Haishun Yang, Hendrik Boogaard, Pepijn A. J. van Oort, Marloes P. van Loon, Kazuki Saito, Ochieng Adimo, Samuel Adjei-Nsiah, Alhassane Agali, Abdullahi Bala, Regis Chikowo, Kayuki Kaizzi, Mamoutou Kouressy, Joachim H. J. R. Makoi, Korodjouma Ouattara, Kindie Tesfaye, and Kenneth G. Cassman. 2016. Can sub-Saharan Africa feed itself? Proc Natl Acad Sci U S A. 2016 113 (52) 14964-14969.

https://www.un.org/sustainabledevelopment/hunger

https://dashboards.sdgindex.org

http://www.yieldgap.org