The Granite Terroir.
Hiroshima’s produce is engineered by **Masa-tsuchi**, a specialized soil composed of weathered granite from the Chugoku mountain range. This sandy, high-drainage strata is technically ideal for citrus viticulture, as it prevents root rot during the rainy season while retaining the mineral complexity required for high-acid synthesis.
Technical Note: The Triple Reflection
The 'Setouchi Climate' provides a stable thermal buffer. Hiroshima's islands utilize 'Triple Reflection'—direct sun, sea reflection, and stone wall radiation—to provide the high-intensity light levels required for Japan's #1 lemon yield.
Seto Growth Spec: Alluvial & Insular
Weathered Granite
(Masa-tsuchi)
2,000+ Annual
Sunlight Hours
The Setouchi Lemon.
Hiroshima is Japan’s primary citrus node, accounting for over 50% of domestic lemon production. The technical advantage of the Setouchi islands—specifically **Ikuchijima**—lies in the steep, south-facing limestone slopes and the "Triple Reflection" effect: sunlight reflecting from the sky, the sea, and the white stone walls of the terraces. This creates a high-intensity thermal environment that maximizes sugar and acid synthesis.
Technical Archetype: The Low-Pesticide Standard
Due to the exceptionally low rainfall and stable humidity of the Inland Sea, Setouchi lemons are archived for their edible rinds, enabling the region's "Le-mosco" spice innovation.
#1 in Japan
(Setouchi Standard)
High Acidity /
Edible Rind
Specimen: Moshio Salt
Ancient "Seaweed Salt" produced by infusing seawater with Sargassum seaweed. The process results in a high-mineral, beige-colored crystal with deep umami.
The Evaporative Trace.
Hiroshima's coastal islands, particularly **Kamagari**, are the world's archive for **Moshio** salt production. This 1,000-year-old technical process involves sun-drying seaweed to concentrate brine before boiling it in massive iron cauldrons. This chemical synthesis creates a salt high in iodine and potassium, essential for the seasoning of Hiroshima's maritime cuisine.
Biological Legacy.
Seeds of Peace
Beyond commercial agriculture, Hiroshima's most significant produce is biological: the seeds of the **Hibakujumoku** (A-bomb survivor trees). These seeds—from Ginkgo, Camphor, and Cherry species—are archived and shared globally with botanical gardens as technical symbols of survival and peace.
Technical Fact: The Green Ribbon
Seeds from the survivor trees have been planted in over 30 countries, creating a global biological network of Hiroshima’s resilience.
Archive: Botanical Resilience
Ginkgo Biloba • Ilex Rotunda • Cinnamomum Camphora
The Logistics Exchange.
Regional Outbound
Setouchi Citrus & Oyster Brine
Hiroshima exports its high-acid lemon yields and premium oysters to the metropolitan hubs of Tokyo and Osaka. These maritime products are archived as high-prestige seasonal markers in national department stores.
Primary Destinations: Tokyo • Osaka • Global Luxury MarketsRegional Inbound
Mainland Grains & Root Staples
To support its high-density urban population, Hiroshima imports bulk rice from neighboring Shimane and root vegetables from the colder northern prefectures. This exchange balances the delta’s specialized maritime economy.
Source Origin: Shimane Grain Belts • Northern HonshuPrecision Resilience.
Documenting the specialized tools born from the delta’s metallurgical history.
The Hiroshima Needle
Hiroshima produces over 90% of Japan’s sewing needles. The technical secret lies in the 300-year-old **Kake-hari** process, a series of 30 specialized grinding and polishing steps that ensure the needle pierces fabric with zero resistance. Originally a side-craft for samurai, it is now an archive of global precision engineering.
Kumano Fude (Brushes)
Located in the foothills of Hiroshima, Kumano is the global capital for artisanal brushes. Each brush is a technical assembly of un-cut animal hair, archived for its superior capillary action in calligraphy and modern cosmetics. 80% of Japan’s artisanal brushes are engineered here.