After wandering around in the west city for several days and fully grasping the local situation, Li Su continued to travel west to Shangyong under the guidance of Shen's family.

To be honest, this area was the first time he had been in this area in two lives. After experiencing it personally, he realized the dangers of the journey - he went down from Xicheng, and in just one day, he could reach Wudang through Dang County, a total of 600 miles.

Of course, this is not a straight line distance, the straight line is only 400 miles, because the Han River is winding and twisting.

The ship's speed is so fast that it shows that the Han River has a huge drop in the Qinling Mountains, second only to the Three Gorges section of the Yangtze River, and is far more turbulent than the Jialing River that Liu Bei's army experienced during the war.

This means that the boat is sailing by paddling or sailing, and it is impossible to go upstream. No wonder in history, after Zhuge Liang's death, during Jiang Wan's rule, Jiang Wan proposed to change the strategy of the Northern Expedition and concentrate troops to recover the three eastern counties, but was opposed by the government and the public, and the reasons for opposition were very unified:

It is easy for Shangyong to attack from Hanzhong from a high place to take down the river and take down the Xicheng. However, if you take down, you will only get a "rebirth of land" and cannot feed back the people's and financial resources in the Hanzhong area.

Because even if Shangyong grows surplus grain and produces excess military supplies, you can't transport it back through the Han River. Unless you have the courage to directly conquer Xiangyang, just taking Shangyong is a waste of national strength. However, the national strength of Shu Han during the Jiang Wan period was obviously unable to defeat Xiangyang and could not defend Xiangyang, so you had to give up.

"I didn't expect that the river in this place is so steep and turbulent. If I don't come once, I really don't know that the transportation infrastructure is worse than Ba ​​County." Li Su looked at the Qinling Mountains, which were standing on both sides of the river, and couldn't help but sigh, and even couldn't help but sang and scold:

"I left Xicheng in the morning among the colorful clouds, and returned to the six hundred martial arts in one day. The monkeys on both sides could not stop crying, and the light boats had already passed thousands of mountains."

"Oh, Li Zhonglang is a good poem. People only know that there are five-character characters in Yuefu, but Zhonglang actually created seven-character characters and is catchy." Shen Kai, the leader, heard his low chant and quickly flattered him. However, Dian Wei couldn't understand anything next to him, and didn't know how to applaud.

Li Su interrupted roughly in a bad mood: "What a bad thing - don't write it down! I am cursing the dangers of the Qinling Mountains, feeling that the people are not easy to get in and out, and the court cannot mobilize the people's power and material resources. What to remember about this vulgar words that criticize the world!

By the way, let’s talk about the important matters, I ask you——You have lived in Shangyong for a long time. Do you know that the people here have any other ways to sail against the current? You can’t go down the river and never drive back every time you take a boat downstream, right?”

Shen Kai was scolded, but he did not dare to be angry at all. Instead, he sighed sincerely: Li Zhonglang is worthy of being a great sage in the world. Not only did he know the destiny, but he also spoke in a good manner. He cursed God so elegantly!

When flattering, the question still needs to be answered. Shen Kai accompanied him to explain carefully: "The people here rarely take boats, occasionally there are only those who transport goods to the downstream. When they return, they encounter a torrent that cannot be rushed through. They can only pull back on the shore and pass by the beach. It is extremely hard, so the business trip is almost extinct."

Li Su listened carefully for a while before she understood the meaning.

He also saw it on the way he came. Not all the river sections were so turbulent, but there were a total of three or four places, and the local gap was too big and too fast. Except for these three or four sections, the other river sections could be flowed by rowing and sails.

Once you reach those turbulent and dangerous shoals, you have to unload the cargo on the boat first, move it to the shore and transport it through this section, then pull the lighter empty ship upstream and pass it through this section, and then load it on.

It's so hard, who is willing to do business here? After Li Su learned about it, he only knew that the people would have so much effort to transport salt, because the Qinling Mountains do not produce salt, and salt has to be eaten.

The price of salt in Shangyong is actually several hundred yuan more expensive than the outside world. The difference is the hard money of the salt transporter.

Li Su couldn't help but think: "The entire Shangyong area should have a population of nearly 100,000, with more than 5,000 households in Xicheng and more than 20,000 households, more than 8,000 households in Shangyong County and more than 35,000 people. The other 77,000 people are included in Fangling.

Since there is demand, and there are so many slopes on both sides of the Hanshui River Valley that can be reclaimed and the irrigation conditions are good, it can be used to resettle refugees in the future.

There are not many places that have been affected by wars now. Shu is very rich. The population of the three counties in the Chengdu Plain has long been saturated and entered the Malthus trap. In the future, the wars in Yongliang caused by Dong Zhuo, Han Sui, Li Ju and Guo Si continue to be in conflict with Yongliang, and the population flows southward. There is definitely no need to put it into the Chengdu Plain, and it will be resettled in Hanzhong.

Then, there are areas with sufficient irrigation and easy to reclaim, namely Brazil and Shangyong. Just find ways to build a few diversion locks that do not need to cut off the river and solve the problem of returning to the ship. It will be a huge profit."

The ship locks are not like the kind of ship locks on the side of the dam of the hydropower station in later generations, and they have to cut off the entire river. Instead, you can dig a little mountain to lead a branch canal out, then set two gates at the end of the branch canal, and use a large water truck to twist the switch.

Especially when encountering places with large drops, when they are still in S-bend, you can cut the bend and straighten it directly on the mountain that blocks the water flow upstream. Choose a store with a relatively short mountain itself and dig a small gap.

The excavation project volume must be a bit large, but because it is only a few dozen meters long, it is still acceptable. The project volume of a ship lock is probably equivalent to digging dozens of miles of canals on a soft plain. The technical level is that of the ship lock in the Ming and Qing Dynasties, and the drop difference is more than three or four stories high.

Otherwise, the gates of this era can only be used to tie up big trees. If they are deeper, they will not be able to find such a long and thick tree. At the same time, they are afraid that the gates formed by big trees will not be strong enough and cannot hold up the deepest water pressure.

Once there is gunpowder that can blast the mountain gap and enough Yongliang refugees, you can consider starting construction.

However, once you really make up your mind to do this, Li Su had to consider the strategic security of Hanzhong. In the past, there was no ship lock, and Xiangyang could not counterattack Hanzhong, so he could not swim up at all. In the future, with the ship lock, it would be much more convenient to come back, so military defenses would have to be on guard.

Li Su noticed that the later generations of Shiyan and Wudang Mountain are now deserted and have no county towns. Shangyong built water on the tributary and had to go up the river to the Danjiangkou in later generations about a hundred miles, but no one developed the river estuary area.

Li Su felt that if we wanted to develop Shangyong, it was necessary to build a county town near Shiyan to cut off the Han River and prevent people from sneaking through. All the locks built by Liu Bei's army in the future must be in the upstream of this place, and no downstream is allowed from now on.

Li Su couldn't help asking Shen Kai: "I see that the estuary of the river where the Dushui River meets the Han River is obviously flattering and fertile than Shangyong, so why didn't the people settle down?"

Shen Kai is a local, and he is very familiar with the geography. He sincerely answered: "Although it is flat and irrigation is convenient, the soil is not strong. It is all because of the Han River. The blocking water flows down here, and the silt and sand accumulates, and swamps are everywhere within dozens of miles."

Li Su nodded, and then he expressed his understanding.

This place is roughly the Danjiangkou Reservoir, the starting point of the South-to-North Water Diversion Project in later generations, plus the Shiyan City in later generations. Since there are reservoir areas and alluvial plains, it must have been a swamp in ancient times.

Later generations of Shiyan were able to build cities, but after thousands of years of sediment deposits, the swamp turned into solid plains.

Now that I want to revitalize the entire Shangyong area, I think about whether there is a way to use this swamp to control it into a farming area. If the entire Shangyong is revitalized here, it will be revitalized.

Li Su didn't understand this very much, so he had to ask for advice in the future.

...

"No matter what, I see that the Wudang Mountain has a good view. We are camping and waiting for a few days before Zhao Yun brings reinforcements to meet up. We will go to Zhuyang. After all, we are Hanzhong soldiers, so it is not good to bring too many people into Nanyang County.

In the future, I think thousands of soldiers can be stationed here to farm. If rice and wheat cannot be planted in the swamp, then taro will be planted. With the food stored, the people in the garrison will be able to be self-sufficient. It’s just that taro is not durable, and you still have to transport some rice and wheat to survive the spring famine."

After inspecting it, Li Su ordered the army to station here, and then stuck Shangyong County's neck, and asked Dian Wei to take some people to clean up the deadly tough members who were dissatisfied with Liu Bei.

Shen Kai, who was standing aside, looked at Li Su's attitude and was slightly worried: Li Zhonglang is very ambitious, is he planning to farm here when fighting against the sky and earth? If outsiders can easily come in in the future, the local emperor of the Shen family will not be considered...

But it shouldn't be that easy. Let's wait and see for a few years first, so there is no need to offend Li Zhonglang.

About a week later, Dian Wei completely cleared Shangyong County and brought the soldiers back. Those county officials who believed in Zhang Luxie could change their own people and even the minor officials brought by Li Su's army.

Almost at the same time, Zhao Yun also arrived at Wudang Mountain with some reinforcements and met with Li Su.

After this week's investigation, Li Su also discovered some common problems in farming in the late Han Dynasty. He took the cool off on Wudang Mountain, writing something in his small notebook, and preparing to go back and tell Liu Bei that he would organize the people to learn new skills.

When he was in Hanzhong before, Li Su discovered that many people in this era did not know much farming skills, or the crops they could grow were very pitiful, and they would not be able to plant them, and no one taught them.

The most advanced agricultural book of this era is "The Four Min Monthly Orders". Li Su had never read it in his previous life, but after he arrived in Hanzhong, he specially asked someone to find a book "The Four Min Monthly Orders" to read it, and found that it was still very different from "Qi Min Yaoshu" during the Southern and Northern Dynasties.

The key is the tone of the author of "The Four Minutes and Monthly Orders". He is obviously the butler of a powerful manor in a large manor, knowing how to organize and dispatch serfs to make full use of the land all year round and take turns to plant various fruits and vegetables. However, few people know this.

Li Su was in Shu and saw that peppercorns were already a mature commercial goods, which were very expensive, and the same was true for tea, and the fruits made from wolfberry sauce. But the people would not "cultivate" this kind of crop. The source of goods came from medicinal farmers who went up the mountain to collect herbs, and all the harvest was pure wild.

Similarly, the place where Li Su wants to manage now can be harvested by water, and it doesn’t matter if there is a swamp, but the people only know how to fish and never think about raising fish. Taro is also wildly dug in the swamp. Few people regard it as a crop, but "earnings from woodcutting."

If we really want to enlighten the people's wisdom, let the surplus population in the mountainous areas of Shu know that "the hillside can also actively plant pepper, tea trees, sugarcane," and let the surplus population in the swamp area learn to raise fish and grow taro. Why does Yizhou have an inverted Malthus trap once to six or seven million people?

There is a long way to go.

The process of regaining the land of Shangyong is almost negligible, but the feeling of powerlessness in other aspects makes Li Su very depressed.

It would be better if he had his spare time to write a copy of "Qimin Yaoshu" by himself. Although he did not understand "Qimin Yaoshu", he could still use the reference of "Four Min Monthly Orders" to ask some old farmers to summarize the methods of planting these economic crops that "are not considered to be crops at present", and converting the records into words of Li Su, which he could still do.

And there is no need to write it yourself, so you can give the text to Zhuge Jin and the others.

Li Su made some trouble and finally left Shangyong Mountain Area in mid-June. On June 18, he left most of his troops on the Yizhou border and stood by. He arrived in Xiangyang with his direct fleet, and then inquired about the situation in the court.

When He Jin learned that Dong Zhuo was still delaying time in Hedong, he had not made any moves yet. The court's restrictions and accusations on the mobilization of foreign troops across the border were indeed much more relaxed than when Emperor Ling was in power.

Only then did Li Su magnify his courage and ask Zhao Yundianwei to bring 500 cavalrymen, as the name of guards who entered the mission to visit the Hajjang, he transferred from Xiangyang to Jingshui and arrived in Nanyang.

Then he boarded the boat and landed from Nanyang, heading straight to Yique Pass on the border between Jingzhou and Sili.
Chapter completed!