Government to Scrap Rice Crop Index; Will Turn to Satellites, AI to Analyze Production

By Miho Naganuma and Haruna Fukushima / Yomiuri Shimbun Staff Writer

20:00 JST, June 17, 2025

The Agriculture, Forestry and Fisheries Ministry is set to overhaul its rice crop survey system by abolishing the rice crop index, a longstanding benchmark for rice yields, and instead exploring new survey methods that utilize satellites and artificial intelligence.

The government’s decision to stop using this nearly 70-year-old statistic stems from growing concerns that it no longer accurately reflects the reality of rice production. With rice prices persistently high, clarifying the actual conditions of production and distribution is a pressing issue.

“The [rice crop index] no longer aligns with the reality of production sites. Moving forward, our goal is to improve the accuracy [of the data] by using the latest technologies to lay a new foundation for agricultural policy,” Agriculture, Forestry and Fisheries Minister Shinjiro Koizumi told reporters on Monday.

Following an observational visit to Fukushima Prefecture the previous day, Koizumi told the reporters that rice farmers had told him there was a “complete mismatch” between the rice-crop index and their reality. “We must take directly to heart what the farmers have clearly stated: their perceptions do not match the index,” Koizumi said.

The rice crop index, which has been published in its current form since 1956, uses annual harvest surveys to calculate yields relative to a “normal year” — a benchmark derived from the average trends of the past 30 years.

Critics often point out that this survey method reflects the effects of past cold weather damage, leading to a discrepancy with recent trends, given that such damage has decreased due to climate change.

Koizumi also indicated plans to boost the accuracy of harvest surveys.

The ministry each year randomly selects 8,000 paddy fields nationwide. They then reap the rice, evaluate its quality and calculate the yield per 0.1 hectares. This figure is then multiplied by the cultivated area in each region to determine the total harvest.

It plans to explore other survey methods, leveraging high-performance combines that can measure rice yields, alongside satellites and AI.

The ministry also plans to review the mesh sizes of the sieves used to categorize rice grains by size. It has been pointed out that the ministry uses sieves with finer meshes than those used by farmers to calculate yields.

This leads to the ministry overestimating harvests and contributes to existing discrepancies. Going forward, the ministry will align its mesh sizes with those used by farmers.

“The [rice crop index] does not align with actual conditions, leading to dissatisfaction among rice producers. Given its tendency to create misunderstandings, its abolition is a welcome move,” said Prof. Katsumi Arahata of Japan International University.

Prime Minister Shigeru Ishiba has instructed Koizumi to investigate and address the factors contributing to the surge in rice prices.

The government plans to discuss the causes of the surge in rice prices and potential countermeasures at a future meeting of the Cabinet ministers related to the issue. It will also consider ways to stabilize prices, including making distribution more transparent and efficient.