Not to mention, it really reminded him of something.

In later generations, there was a dynasty called the Great Song Dynasty, and the land area was only about a quarter of the size of the heyday of the Tang Dynasty.

But this is not the point, the point is that the merry Han dynasty, with only a quarter of the land area of the Tang Dynasty, fed the dynasty's population of nearly 100 million.

You must know that the peak population of Datang has not been able to break through this value even in the prosperous period of the Kaiyuan Dynasty, which is praised by the world.

And the fundamental reason is that because of grain, Datang's grain output cannot support so many people.

But what the Tang Dynasty didn't do, that dynasty did.

With only a quarter of the area of the Tang Dynasty, the grain that can feed so many people of the dynasty can be grown.

What is the reason?

Zhang Zheng remembered reading it in a book, it seems that it was because an emperor of that dynasty introduced a new variety of rice from a small country in Southeast Asia.

That kind of rice seems to be able to be harvested three times a year, even in the Jiangbei area, it can also be harvested twice a year.

What's more, that kind of rice can be harvested twice and three times a year, and the key is that its yield is nearly one-third higher than that of the native rice varieties in the Central Plains.

Champa rice! Three words gradually became clear in Zhang Zheng's mind, this is the name of that kind of rice.

The high-yield grain on the other side of the ocean can't be obtained, but the high-yield grain introduced during the Great Song Dynasty doesn't make sense that Datang doesn't have it.

With Zhang Zheng's understanding of the monkeys in Southeast Asia, it is impossible to cultivate such a high-yield rice seed in just a few hundred years from the Tang Dynasty to the Great Song Dynasty.

They don't have that intelligence, and they don't have that ability.

Therefore, that kind of rice must have been grown in the land of Southeast Asia from ancient times to the present.

It was only in the Song Dynasty that the Han people learned about it. Then it was introduced, improved, and allowed that kind of rice to grow on the land of Middle-earth, feeding the Han people for hundreds of years.

It was not until the end of the Ming Dynasty that more high-yielding and drought-tolerant potatoes and corn were brought into China by foreign missionaries, and Champa rice was gradually replaced by those grains.

That's it, Zhang Zheng shook his fist at the air, and he really couldn't hold back the excitement in his heart.

Zhang Zheng knows a lot about the history of the Tang Dynasty, but these small countries around the Tang Dynasty are just black-eyed.

At most, I know some countries that have been buffed by Li Erdie, such as Turkic, Gaochang, Goguryeo, Tubo and other well-known countries.

And Nagada in Southeast Asia, not to mention what the names of those small countries were during the Tang Dynasty, it is later generations, Zhang Zheng also knew about the Sino-Vietnamese War, or because it was mentioned in the history books.

In addition, Zhang Zheng didn't know anything.

Therefore, Zhang Zheng decided to ask Li Chengqian directly, Li Chengqian is the prince, and the situation of neighboring countries is one of Li Chengqian's compulsory subjects.

"Chengqian, do you know where the country of Champa is?"

But Li Chengqian disappointed Zhang Zheng, hearing the name Zhancheng, Li Chengqian was obviously a little confused, and cautiously asked Zhang Zheng for verification: "Zhancheng, is there such a country in the world?" ”

Ga!

Zhang Zheng's smile froze directly on his face.

"You don't know?"

"I don't know......"

Li Chengqian's expression was a little innocent, he really hadn't heard of the country of Zhancheng.

Zhang Zheng asked with some reluctance: "Then do you know what countries in Southeast Asia are now?" ”

Southeast Asia is so big, millions of square kilometers of land, I don't know the specific place name, where to find Zhancheng rice by myself, and looking for a needle in a haystack is not such a fishing method.

"Southeast Asia, what's that?"

"Well, it's on the peninsula south of the Six Edicts."

Zhang Zheng explained that the six edicts are the Yunnan of later generations, and the south of Yunnan is the Indochina Peninsula.

"Oh, I know this, there are Linyi, Zhenla, Panguo, Fallen and Luo, Wolf Tooth Repair, Buluo ......"

Li Chengqian immediately reported a large list of place names, and Zhang Zheng's eyes were full of gold stars.

As far as there are so many small countries in Nagada in the Indochina Peninsula, Zhang Zheng said that it is really an eye-opener.

"Alright, stop!"

Zhang Zheng raised his hand and interrupted Li Chengqian's report of the names of the dishes, as if he were announcing the names of those small countries.

Li Chengqian paused, and rolled his eyes at Zhang Zheng.

"You didn't ask."

Zhang Zheng didn't bother to bother with him, and asked directly: "Is there a country called Zhancheng, or a country that used to be called Zhan?" ”

Li Chengqian shook his head and replied: "I don't know much about this, you can go back and ask the people of Honglu Temple, they should know." By the way, why do you ask this? ”

Zhang Zheng spread his hands, leaned on the big bed in the carriage, and said casually: "For food." ”

But this sentence aroused Li Chengqian's interest.

"For food, what grain?"

Hearing Li Chengqian say that he didn't know the country of Zhancheng, Zhang Zheng was a little excited.

"A kind of rice, called Champa rice, has a high yield and can be harvested three times a year."

Seeing Zhang Zheng's lazy and lazy expression, Li Chengqian couldn't tell whether what he said was joking or serious, so he had to reply.

"Three crops a year, Brother Sheng, you have hysteria again......"

Then he also followed Zhang Zheng's example and lay down.

Zhang Zheng didn't talk, but thought in his mind about the possibility of sending someone to the Indochina Peninsula to conduct a carpet search.

Since even Li Chengqian didn't know where the country of Zhancheng was, it was in vain to ask Honglu Temple.

It is more likely that the current country is not called Cham at all, but by some other messy name.

And since that kind of rice is named after Champa, it is certainly impossible to grow everywhere in Southeast Asia.

If that were the case, with the frequency of trade between the Tang Dynasty and those small countries in Southeast Asia, it would not have been discovered and introduced until the Song Dynasty.

"Actually, Brother Zheng'er, you don't have to care where the city of Nalaoshzi is, just gather the envoys of those small countries on the peninsula and ask them one by one.

If there really is the kind of rice that can be harvested three times a year, there is no reason why those envoys will not know. Anyway, those envoys of small countries who are stationed in the Quartet are idle. ”

The two were silent for a long time, and a faint sentence came out of Li Chengqian's mouth.

After listening to Li Chengqian's words, Zhang Zheng was stunned for a moment, and a sense of shame that his IQ was pressed to the ground by the ancients rose from his heart.

yes, why bother to find it yourself, why can't they send it themselves?

With the prestige of Datang, this is a very simple thing.

Zhang Zheng was a little dazed, then ashamed, and then annoyed and angry.

", of course I knew I could do that."

"You know you're still asking."

"Shut up."

"Oh, Brother Zheng'er, you didn't expect that, did you?"

Li Chengqian looked at Zhang Zheng with the eyes of the mentally retarded, and Zhang Zheng was suddenly angry, relying on his superiority in IQ as a traverser, it has always been his patent to look at people with this kind of eyes.

Now there are people who use this kind of view of God to see themselves, which is unbearable or unbearable.

Then, Zhang Zheng made a move, and immediately after, the two scuffled.