Evaluating the 2019 NARO-APCC Joint Crop Forecasting Service yield forecasts for Northern Hemisphere countries

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  • 1 National Agriculture and Food Research Organization, 3-1-3 Kannondai, Tsukuba, Ibaraki 305-8604, Japan
  • 2 APEC Climate Center, 12, Centum 7-ro, Haeundae-gu, Busan 48058, Republic of Korea
  • 3 European Commission, Joint Research Centre, Ispra (VA), 21027, Italy
  • 4 FINCONS SPA, Vimercate (MB), 20871, Italy
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Abstract

Forecasting global food production is of growing importance in the context of globalizing food supply chains and observed increases in the frequency of climate extremes. The NARO-APCC Crop Forecasting Service provides yield forecasts for global cropland on a monthly basis using seasonal temperature and precipitation forecasts as the main inputs, and one year of testing the operation of the service was recently completed. Here we evaluate the forecasts for the 2019 yields of major commodity crops by comparing with the reported yields and forecasts from the European Commission’s Joint Research Centre (JRC) and the United States Department of Agriculture (USDA). Forecasts for maize, wheat, soybean and rice were evaluated for 20 countries located in the Northern Hemisphere, including 39 crop-producing states in the US, for which 2019 reported yields were already publicly available. The NARO-APCC forecasts are available several months earlier than the JRC and USDA forecasts. The skill of the NARO-APCC forecasts was good in absolute terms, but the forecast errors in the NARO-APCC forecasts were almost always larger than those of the JRC and USDA forecasts. The forecast errors in the JRC and USDA forecasts decreased as the harvest approached, whereas those in the NARO-APCC forecasts were rather stable over the season, with some exceptions. Although this feature seems to be a disadvantage, it may turn into an advantage if skilful forecasts are achievable in the earlier stages of a season. We conclude by discussing relative advantages and disadvantages and potential ways to improve global yield forecasting.

Denotes content that is immediately available upon publication as open access.

Corresponding author: iizumit@affrc.go.jp (T. Iizumi)

Abstract

Forecasting global food production is of growing importance in the context of globalizing food supply chains and observed increases in the frequency of climate extremes. The NARO-APCC Crop Forecasting Service provides yield forecasts for global cropland on a monthly basis using seasonal temperature and precipitation forecasts as the main inputs, and one year of testing the operation of the service was recently completed. Here we evaluate the forecasts for the 2019 yields of major commodity crops by comparing with the reported yields and forecasts from the European Commission’s Joint Research Centre (JRC) and the United States Department of Agriculture (USDA). Forecasts for maize, wheat, soybean and rice were evaluated for 20 countries located in the Northern Hemisphere, including 39 crop-producing states in the US, for which 2019 reported yields were already publicly available. The NARO-APCC forecasts are available several months earlier than the JRC and USDA forecasts. The skill of the NARO-APCC forecasts was good in absolute terms, but the forecast errors in the NARO-APCC forecasts were almost always larger than those of the JRC and USDA forecasts. The forecast errors in the JRC and USDA forecasts decreased as the harvest approached, whereas those in the NARO-APCC forecasts were rather stable over the season, with some exceptions. Although this feature seems to be a disadvantage, it may turn into an advantage if skilful forecasts are achievable in the earlier stages of a season. We conclude by discussing relative advantages and disadvantages and potential ways to improve global yield forecasting.

Denotes content that is immediately available upon publication as open access.

Corresponding author: iizumit@affrc.go.jp (T. Iizumi)
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