Do you know how much grain a Ming Dynasty farmer in Zhangzhou could get from one mu of land?

100 to 150 jin.

After paying taxes, he kept less than 75%.

But that’s not the most startling number. What really got me was this: a patch of land no bigger than the Jiulong River plain somehow supported far more people than the official records showed.

I spent a long time digging through the Wanli Zhangzhou Fu Zhi: Tax and Corvee. What I found was a paradox. The census rolls compiled in 1381 were already seriously outdated by the 1570s. Too many people had evaded taxes and corvee labor, slipping into places the government couldn’t see.

More mouths, same land. 32 volumes of chronicles, all trying to solve the same equation.

One Mu, Three Ledgers

In 1381, Zhu Yuanzhang created the “Yellow Register” and the “Lijia” system. Zhangzhou was carved into 88 Li. Each Li paid a fixed grain tax, calculated down to the spoonful — six decimal places of precision.

But the system had a built-in flaw: it assumed the population was static.

By the 1570s, the number of people actually living on the Jiulong River plain far exceeded what the books showed. The official grain quota hadn’t changed, but there was less and less to go around. Food supply in the Zhangzhou plain was tightening.

What could they do?

Two things: expand outward, or dig deeper.

Into the Hills

When the plain ran out of room, the people of Zhangzhou moved into the hills.

In the mid-to-late Ming, the government established Pinghe and Haicheng counties. It sounds like an administrative decision. It was really an after-the-fact recognition — people had already moved to the mountains and coast, and the government was just following them to collect taxes.

These new mountain terraces added about 20% to the prefecture’s total grain output. Not a huge number. But enough to keep many people alive.

Opening new land wasn’t enough, though. They also had to make each mu produce more.

How? Water.

The “Water Conservancy” volume of the Wanli chronicle is very specific: in Longxi County alone, along both banks of the Jiulong River, there were 31 major irrigation projects. Dams, sluices, canals — they brought drought-resistant Champa rice to more fields. Grain production stability increased by about 15%.

Silver Changed Everything

1567. Yuegang opened.

This wasn’t just about trade. When silver started pouring into Zhangzhou, something fundamental shifted: farmers could now pay their taxes in silver instead of grain.

88 ships a year left Yuegang, carrying silk and porcelain, and returned filled with silver. With silver in hand, Zhangzhou could buy grain from elsewhere when local harvests fell short. The Tongji Bridge and Yuegang docks on the Jiulong River became the “lifeline” for food.

One line in the Wanli chronicle kept pulling me back: “The merchants benefit from silver conversion.”

A small lever moving a heavy weight.

A Granary and a Family’s Grit

Markets weren’t enough. What about natural disasters?

Zhangzhou maintained Preparation Granaries, Ever-Normal Granaries, and Community Granaries. After the 1552 earthquake, it was the grain stored in these warehouses that kept things from falling apart.

But what struck me more was the role of gentry families.

78 stone steles still record their actions: donating “school lands,” setting up “community granaries.” This wasn’t government action. It was clan action. Where the official system couldn’t reach, families kept the population alive in their own way.

The Survival Algorithm in 32 Volumes

When I put it all together — the 1381 Lijia data, the 1570s hidden population estimates, the silver inflows after 1567 — I saw that the people of Zhangzhou were doing only one thing: on a fixed piece of land, they kept finding new ways to survive.

Into the hills. Into the water. Or using silver to buy grain.

32 volumes of chronicles, and every one of them says the same thing: the land is fixed. But the people who work it are not.

Next time you peel a longan, think about this — the one in your hand might have been paid for, five hundred years ago, by a Zhangzhou farmer with one thin mu of land and an entire irrigation system.