Li Ke's words made all the ministers speechless, but after a moment of silence, Fang Xuanling spoke: "Your Highness, there is no problem with what you say, but I don't know much about how the family of the gate valve family chooses us this day, so I can only say that I will guide them as much as possible." This family has several different concepts, not to mention that there are so many gate valve families in the world. ”

Fang Xuanling's words are undoubtedly for everyone to step down.

Li Ke naturally didn't mind, if Lao Li hadn't asked him to talk about it, Li Ke wouldn't have bothered to say this.

"Well, there is no problem with Wei Guogong's words, everyone has to pay more attention to this aspect, in addition, Dad, and since everyone is here, I have something to tell you." Li Ke said.

"You say." Li Shimin said quietly.

"I want to restrict the cultivation of land and migrate people in the main loess area of Kannai Province and Hedong Province." Li Ke opened his mouth and said, "Go, Huo Gang will bring a map over." ”

"Yes." Huo Gang, who was in the distance, turned around and went to look for the map in the goods loaded and unloaded next to him.

Everyone has no concept of the Loess Region or the Loess Plateau, but everyone must know the two ways that Li Ke said, "Why? Li Shimin asked a little strangely.

"Soil erosion." Li Ke said.

"Soil erosion?" Everyone was a little dazed.

"Most of you have read history books, the Four Books and the Five Classics, the Spring and Autumn Period, etc., have you ever had the impression that when was the Yellow River called the Yellow River? Why is it called the Yellow River? Li Ke looked at everyone and asked.

Everyone was stunned for a moment, paused for dozens of seconds, and Li Chunfeng, who was in the crowd, spoke: "Back to Your Highness, if the minister remembers correctly, it was around the end of the Sui Dynasty that some literati began to call the name of the Yellow River according to the names of some people in the middle and lower reaches of the Yellow River. ”

"That's right." Li Ke nodded very dryly, "Why is it the end of the Sui Dynasty, and not the earlier dynasties before, it is because the water of the Yellow River began to become turbid." ”

"In the middle and lower reaches of the Yellow River, the water quality began to turn yellow, including near the mouth of the Bohai Sea, the originally clear ocean has also become a dull yellow color, I asked my ancestors near the Bohai Sea to live near the Yellow River estuary, they said that before my ancestors, when the Yellow River entered the Bohai Sea, the water flow was still clear, until now it is covered with a lot of sediment."

"And this sediment comes from the loess area in the middle and upper reaches of the Yellow River, which is what I call Hedong Road and Guannei Road."

Everyone was a little confused, and to be honest, they understood it, but they didn't understand the point of this.

Huo Gang had already taken the map, and Li Ke called over the two little eunuchs to prop up the map, and then used his hands to draw a picture of the area where the Loess Plateau was located on the map.

"Ladies and gentlemen, this is the area where the Loess Plateau is located, and it is also the main cultivation area for the development of our Chinese civilization to this day."

"Zhuangzi" has clouds: the river is exhausted and the valley is empty, and the hills are deep and solid. It means soil erosion, because the number of people in these places is increasing year after year, and when the people can't survive, they will open up more wasteland to grow food, but after clearing the land to grow food, it will lead to a consequence, that is, the number of trees and forests will decrease, so that the root system of trees that stabilize the earth will be reduced, and when the water flows through, it will carry away a large amount of sediment. ”

"Some officials in the Ministry of Industry who often manage the banks of rivers and flood disasters should know that if a river flows through a flat plain and is covered with mud on both sides, there will often be some mud on the banks of the river into the river, and the banks of the river are changing year after year, but if the banks of a river are all trees, then the banks of the river may not change much for decades, or even centuries."

"That's what tree roots do to stabilize the riverbank."

"The principle is actually the same as when we build a house, we should mix wheat and rice straw in the yellow mud and then put it on the wall, including I use cement to make iron reinforced concrete, and I want to add iron bars to the cement to increase the strength. The roots of the trees in the earth play this role. Li Ke said.

As soon as Li Ke said this, some ministers who were not good at architecture instantly understood, and most of them looked at Li Ke with some surprise, His Royal Highness did not expect to be able to connect the truths of these completely different activities.

"These places in Guannai Province and Hedong Province are a large number of loess areas, and in the past dynasties, this area was also a relatively concentrated area of population, so a large number of people cut down trees for arable land and reclaimed wasteland, and there are fewer and fewer trees in these places, and soil erosion is becoming more and more serious, such as on some hillsides, if they are originally covered by forests and vegetation, even if it rains heavily, it is nothing."

"But without trees and a lot of vegetation cover, once it rains heavily, the rainwater will quickly gather to form some small streams flowing down the slopes with mud, and many loess mountains on the Loess Plateau have formed thousands of ravines, which is a favorable proof of soil erosion."

"Then these streams will gradually converge into rivers, these rivers are tributaries of the Yellow River, and finally the tributaries carry sediment into the Yellow River, the water of the Yellow River begins to become turbid, in the long run, I am afraid that at most one or two hundred years, the lower reaches of the Yellow River will be diverted because of a large amount of sediment accumulation, river accumulation! At that time, I am afraid that it will be the potential of flooding, and starvation will be everywhere. ”

Li Ke's words are not untargeted, the diversion of the Yellow River is very terrifying, it is not just a few simple lines of handwriting in history.

Anyone who has been through floods for 98 years in the future knows how terrible it is, you must know that it is just a flood disaster, but what about the diversion of the river?! In ancient times, there was no strength to seal the breach.

"What His Royal Highness said is extremely true, I was born in Taiyuan Wang, on the mountain near my home, there is a hill that originally had a lot of trees, I used to go there when I was a child, and there are no thousands of ravines on the mountain, but then the people reclaimed the wasteland, and the trees on the mountain were cut down, and now the hill has been washed by the rain to form several deep ravines."

"Now that I think about it, where is the dirt in that ravine? I'm afraid they all merge into the Yellow River. Among the ministers, a middle-aged man in his forties spoke.

"Does Your Highness mean that we are going to start planting trees in this loess area?" Duan Lun asked with a bitter face, don't think about it, this is the matter of his Ministry of Industry.

"Yes, planting trees is one thing, and all the places that have not been cleared will be allowed to plant trees and take care of food during the slack period!" Li Ke said very simply, in this era, as long as you take care of the food and let the people deal with it during the leisure time, it is estimated that the whole family of the people is willing to come out to help, and the children are free.

"In addition to the wasteland, in the remaining people's farmland, according to some local weather and climate, see if there are any fruit trees that meet the local characteristics, these fruit trees can also fix the water and soil, and secondly, they can also increase some income for the people."

"There is also the Ministry of Industry and the doctors of the Tai Yi Department can investigate how many medicinal herbs grow in the local mountains, and the conditions for the growth of these medicinal herbs, for example, some like to grow under the trees, you can cooperate with the people to plant trees and then plant them between the saplings and saplings. are all promoted. ”