A live-streamed Chinese language lesson under the sky—the ancients were taken aback.

Half a month later, the sky lit up again, and everyone discovered that it was Master Shen, whom they hadn't seen for a long time.

Shen Moyan stood on the podium, with a line of words written on the blackboard behind him: "Delighted to see the rice and millet ripple like waves."

Rice and beans? Are they preparing to teach us how to grow them?

Many farmers who had been working diligently and ignoring the sky finally put down their hoes and prepared to listen carefully to what the sky was saying.

Under the sky, countless people eagerly awaited.

Shen Moyan didn't open her textbook; she first glanced at the whole class.

"Before we begin, I have a question for you all." She rested her hand on the edge of the podium. "What did you have for breakfast today?"

The responses were scattered: steamed buns, fried dough sticks, bread, milk; some people said they hadn't eaten.

A boy in the back row shouted "Instant noodles!" and the whole class burst into laughter.

Shen Moyan smiled and nodded. "Then let me ask you another question: have you ever wondered where all this food comes from?"

A girl with a ponytail raised her hand: "Bought at the supermarket."

"What about before the supermarket?"

"Made in a factory."

"What about before the factory?"

The girl paused for a moment, then said, "It grows in the ground."

"Yes, it grows in the ground." Shen Moyan turned around and wrote two words on the blackboard: grain.

"Your generation grew up in the city and could eat whatever you wanted."

But you may never have considered this: decades ago, people were starving to death on this land.

Shen Moyan's eyes were filled with nostalgia and gratitude. "The text we're going to read today is about someone who saved us from going hungry."

"Food is the most important thing for people."

In essence, the history of our Chinese nation is a history of seeking survival from the land.

Our ancestors pondered for thousands of years how to harvest more millet and more rice.

Before we delve into the text, let's watch a video to see what efforts they've made on this land.

She pressed the projector remote control.

The large screen behind me lit up, and the scene began with primitive farming on a piece of yellow earth.

A barefoot farmer is turning over the soil with a wooden plow, his movements slow and laborious.

His back was bent like a bow, his ankles were stuck in the mud and water, and he had to stop to catch his breath after turning over each furrow.

Subtitle: Pre-Qin period, wooden plow and stone hoe, yield about fifty kilograms per mu.

Ying Zheng tapped his finger lightly on the imperial desk.

The yield of millet per mu in Daqin is about fifty kilograms, according to the annual report submitted by the official in charge of millet.

The numbers on the screen were exactly the same.

How could people two thousand years from now know what the yield per acre was in his time?

However, these are not details we should be concerned about right now.

He glanced down at the court, where more than a dozen minor officials were standing by, ready to record the contents of the sky in detail.

Since the last time the papermaking and world map flashed across the sky, many emperors have increased the number of people tasked with recording them.

The video continued.

During the Western Han Dynasty, iron plows and ox-drawn plows became widespread.

The scene shows a farmer driving an ox pulling an iron plow, turning up deep and even soil.

His wife followed behind, sowing seeds, while the children squatted on the edge of the field catching grasshoppers.

A seed drill appeared nearby; it had three legs and a seed container, and it could dig furrows, sow seeds, and cover them with soil at the same time.

Subtitle: Zhao Guodaitian method, seed drill, increased yield per mu to about seventy kilograms.

Guanzhong.

Zhao Guozheng was squatting on the edge of the field, teaching farmers how to select seeds.

The light from the sky fell on his face, and he looked up to see the seed drill he had invented.

The same.

Tianmu said that this tool was used for two thousand years in later generations.

His hand stopped, his fingers still holding a seed, suspended in mid-air.

The weight of two thousand years suddenly pressed down on that tiny seed, so heavy that he could barely hold it.

Then he suddenly came to his senses, turned around and shouted to the farmer next to him, "Quick! Go find bamboo slips! Draw the picture of that seed drill on the sky!"

His voice trembled with excitement. The seed drill was almost identical to his design, but the image on the screen was clearer than any of his drawings. The angles of the three legs and the spacing of the seeds were immediately apparent.

He knew that his design of the seed drill was not perfect, and the images on the screen filled in the gaps in his thinking about several details.

The farmer hesitated for a moment, then took off running.

The video continues.

During the Sui and Tang dynasties, the curved-shaft plow nimbly turned in the paddy fields of Jiangnan, and the waterwheel continuously drew water day and night under the impact of the water flow, with the splashing water creating a rainbow when illuminated by the sunlight.

An old farmer sat on the edge of the field, watching the waterwheel turn by itself. He no longer needed to bend over to carry water, and the wrinkles on his face smoothed out.

Subtitle: Curved plow, waterwheel, yield approximately 100 kilograms per mu.

In the Taiji Hall, Li Shimin stood under the corridor and saw the waterwheel, his eyes twitching slightly.

That thing doesn't need human power; it can turn on its own as long as there's water flowing, day and night without stopping.

He turned to Wei Zheng and said, "Minister Wei, have you seen the structure of the waterwheel clearly? Draw it down and have the Ministry of Works make it immediately. If all the paddy fields in Jiangnan can be equipped with this, the irrigation cost can be reduced by more than half."

Wei Zheng had already ordered someone to record it. Several officials serving as scribes in front of the palace were bent over their desks, writing swiftly, recording the shape, size, and method of setting up the waterwheel on the sky screen.

Li Shimin watched the scene of the curved plow turning in the paddy field for a while, and murmured, "That plow can turn in the paddy field... The straight plow in Guanzhong can't do that."

"There are many paddy fields in Jiangnan, so this plow should also be remembered."

By the Song and Yuan dynasties, Champa rice was a golden expanse in the terraced fields of Jiangnan, with waves of rice surging and peasant women wearing straw hats bending over and swinging their sickles.

The cropping system of alternating water and dry land crops and double cropping of rice and wheat ensures that the land is never idle throughout the year.

Subtitle: Champa rice is being promoted and can be planted in multiple crops, with a yield of about 120 kilograms per mu.

Jiangnan.

An old, barefoot farmer was sitting on the edge of the field, taking a break.

He saw terraced fields and waterwheels appear in the sky and grinned.

His family has farmed terraced fields for generations. The field at the foot of the mountain is irrigated by a waterwheel, while the field halfway up the mountain relies on the weather for water.

He had grown Champa rice, an early-maturing rice variety that came from Champa and matured half a month earlier than local rice.

These two weeks can be life-saving during a time of food shortage.

He pointed to the sky and said to his son, "Champa rice, it's good stuff, your grandfather's generation didn't have it."

The scene shifts to the Ming and Qing dynasties, where the ecological cycle system of mulberry-dike-fishponds is as sophisticated as a machine: mulberry trees are planted on the dikes, mulberry leaves are used to feed silkworms, silkworm excrement is used to feed fish, and pond mud is used to fertilize the fields.

Subtitle: With meticulous cultivation, the yield is about 150 kilograms per mu.

Yingtian Prefecture.

Zhu Yuanzhang sat on the throne in the Fengtian Hall, the light from the sky reflecting on his aged face.

Upon seeing the mulberry-dike-fishpond, he suddenly sat up straight.

He never imagined that planting mulberry trees, raising silkworms, raising fish, and fertilizing fields could be made into a cycle, so that no one would waste anyone else's resources.

Zhu Yuanzhang picked up his vermilion pen and wrote quickly on the memorial: "Order the Ministry of Revenue to copy the method of mulberry-dike-fishpond described in the imperial edict and distribute it to all prefectures, states and counties. All places with rivers and ponds may try it out."

After he finished writing, he paused and added a sentence: This method does not cost money or grain, only manpower, and is most in line with the people's sentiments.

The video's narration slowly begins: "From the pre-Qin period to the Ming and Qing dynasties, from the wooden plow to the curved plow, from fallow system to two harvests a year, from the sweeper to the waterwheel."

For more than two thousand years, countless generations of farmers have bent over this land, increasing the yield per mu from fifty kilograms to one hundred and fifty kilograms.

Every farm tool and every farming system is the wisdom that a generation has forged from the sweat and toil of the soil.

However, the upper limit of 150 kilograms per mu was locked for a full six hundred years.

The image freezes.

Shen Moyan pressed the pause button and turned to look at the whole class.

The classroom fell silent for a moment.

What are your thoughts after watching this video?

A girl with a ponytail in the front row raised her hand: "Even under such difficult conditions, people in ancient times were always trying to increase production."

"Yes." Shen Moyan wrote four words on the blackboard: meticulous cultivation.

"From the pre-Qin period to the Ming and Qing dynasties, the core idea of ​​Chinese agriculture can be summarized in these four words."

With limited land, we can invest more manpower and more meticulous management, making one acre of land feel like two.

This approach increased the yield per mu from fifty kilograms to one hundred and fifty kilograms, feeding an ever-growing population.

However, there is a limit to how meticulous and detailed the work can be.

No matter how neatly you build the paddy field ridges, how densely you plant the seedlings, or how thoroughly you weed, the amount of rice that can be produced per acre ultimately depends on the seeds.

This is the ceiling of traditional agriculture; within the same variety, no matter how meticulously you cultivate it, you can never break through its genetic limits.

She pressed the remote control, and the table showing the changes in grain yield per mu appeared on the big screen.

From the pre-Qin period to the Ming and Qing dynasties, that line crawled almost flat along the ground for two thousand years, and then suddenly became steep in the second half of the twentieth century.

Like a seedling breaking through the soil.

"But the yield per mu jumped from 150 kilograms to 470 kilograms."

This leap took only fifty years.

The person who accomplished this is the protagonist of today's lesson.