An unstable supply of commodity crops and associated increases in food prices are recent and growing concerns due to increasing temperatures, changing precipitation patterns and increasing frequencies of some extreme climate events. Agricultural monitoring and forecasting can support national food agencies, international organizations and commercial entities in better responding to anticipated production shocks induced by seasonal climate extremes. The global seasonal crop forecasting service jointly developed in 2018 by the National Agriculture and Food Research Organization (NARO), Japan and the Asia-Pacific Economic Cooperation Climate Center (APCC), South Korea is an emerging and unique example of agricultural forecasting tailored to major commodity crops (maize, rice, wheat and soybean). The present study evaluates the skills of the NARO-APCC yield forecasts in five countries located in the Southern Hemisphere (the 2019/20 season in Australia and Uruguay and the 2018/19 season in Argentina, Brazil and Paraguay), following the previous assessment for the 2019 season in Northern Hemisphere countries. The results reveal that the NARO-APCC forecasts can capture the major characteristics of reported state yields even six months before harvesting, with variations by crop (the correlation coefficients calculated between the forecasted and reported state yields within a country in a season of interest were frequently over 0.8 for maize, rice and wheat and approximately 0.3 for soybean). In three-fifths of the 122 crop-state combinations assessed here, the NARO-APCC forecasts showed smaller forecast errors than those of the simple forecasts derived solely based on the reported yields. The findings of this study emphasize the novelty of long-range crop forecasting, such as the NARO-APCC forecasts that provide yield forecast information available even just after planting. Together, the NARO-APCC forecasts and existing regional crop forecasts contribute to making objective yield forecast information more seamlessly available throughout the season from planting to harvesting than what is currently available.

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评估 2019/20 年度 NARO-APCC 南半球国家联合作物预测服务的地方级产量预测技能

由于气温升高、降水模式变化和一些极端气候事件的频率增加，商品作物供应不稳定以及相关的食品价格上涨是近期和日益严重的问题。农业监测和预报可以支持国家粮食机构、国际组织和商业实体更好地应对季节性气候极端事件引起的预期生产冲击。由日本国家农业与粮食研究机构（NARO）和韩国亚太经合组织气候中心（APCC）于 2018 年共同开发的全球季节性作物预测服务，是针对主要农作物的农业预测的新兴独特范例。商品作物（玉米、水稻、小麦和大豆）。本研究评估了南半球五个国家（澳大利亚和乌拉圭的 2019/20 产季以及阿根廷、巴西和巴拉圭的 2018/19 产季）的 NARO-APCC 产量预测技能，此前评估为北半球国家的 2019 年季节。结果表明，NARO-APCC 的预测甚至可以在收获前 6 个月捕捉到报告的州单产的主要特征，并因作物而异（一个国家在感兴趣的季节内预测和报告的州单产之间计算的相关系数经常玉米、稻米和小麦超过 0.8，大豆约为 0.3）。在此处评估的 122 种作物状态组合中，有五分之三，NARO-APCC 预测显示的预测误差小于仅基于报告产量得出的简单预测的预测误差。这项研究的结果强调了长期作物预测的新颖性，例如 NARO-APCC 预测即使在播种后也能提供可用的产量预测信息。NARO-APCC 预测和现有的区域作物预测共同有助于使从种植到收获的整个季节的客观产量预测信息比目前可用的信息更加无缝。