Datang: Li Shimin begged me to rebel

What Li Ke said made all the officials speechless, but after a moment of silence, Fang Xuanling spoke up: "Your Highness, there is nothing wrong with what you said, but I don't care how the world's powerful families choose." I know too well, I can only say try to guide them. This family has several different ideas, let alone so many powerful families in the world."

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

Li Ke naturally didn't mind, if it wasn't for Lao Li asking him to talk about it, Li Ke wouldn't bother to talk about it.

"Well, there is nothing wrong with Wei Guogong's words. Everyone needs to pay more attention to this aspect. Besides, since everyone is here, I have something to tell you." Li Ke said.

"Tell me." Li Shimin said calmly.

"I want to restrict the arable land and relocate the people in the main loess area of ​​Guannei Road and Hedong Road." Li Ke said, "Go, Huo Gang brought a map."

"Yes." Huo Gang in the distance turned around and went to look for a map in the cargo loaded and unloaded next to him.

Everyone has no idea about the loess area or the loess plateau, but everyone must know the two ways Li Ke said, "Why?" Li Shimin asked a little strangely.

"Soil erosion." Li Ke said.

"Soil erosion?" Everyone was at a loss.

"Most of you have read history books, such as the Four Books and Five Classics, the Spring and Autumn Annals, etc. Do you have any impressions, when was this Yellow River called the Yellow River? Why is it called the Yellow River?" Li Ke looked asked everyone.

Everyone was stunned for a moment and paused for tens of seconds. Li Chunfeng among the crowd said: "Returning to Your Highness, if I remember correctly, around the end of the Sui Dynasty, there were some literati who were based on the middle and lower reaches of the Yellow River. Some people began to call the name of the Yellow River."

"That's right." Li Ke nodded bluntly, "Why is it the end of the Sui Dynasty instead of the earlier dynasties? It's because the water of the Yellow River has become turbid."

"The water quality in the middle and lower reaches of the Yellow River began to turn yellow, including the originally clear ocean near the mouth of the Bohai Sea. I asked the people whose ancestors lived near the mouth of the Yellow River near the Bohai Sea. They said Before our ancestors, when the Yellow River entered the Bohai Sea, the water flow was still clear, until now it is carrying a lot of silt.”

"And these sediments come from the loess area in the middle and upper reaches of the Yellow River, which is what I call the East Road and Guannei Road."

Everyone is a little puzzled. To be honest, they can understand, but they don't understand the key point of this.

Huo Gang had already brought over the map, and Li Ke called over two young eunuchs to prop up the map, and then drew on the map for everyone the approximate area where the Loess Plateau is located.

"Everyone, this area is the area where the Loess Plateau is located, and it is also the main farming area where our Chinese civilization has developed to this day."

"There is a saying in "Zhuangzi": the rivers are exhausted and the valleys are empty, and the hills are full of abysses. It means soil erosion, because the number of people in these places has increased year by year, and when the people can't survive, they will open up more land. Planting food in the wasteland, but opening up wasteland to plant food will lead to a consequence, that is, the number of trees and forests will decrease, thereby reducing the root system of trees that stabilize the land, and when water flows through, it will carry away a large amount of sediment.”

"Some officials of the Ministry of Industry who often deal with river banks and flood disasters should know that if a river flows across a flat plain, there are mud on both sides, and some mud will often enter the river from the banks of the river, and the river banks are also changing year after year. , but if the banks of a river are full of trees, then the banks of the river may not change much for decades or even hundreds of years."

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

"The principle is actually the same as when we build a house, we need to mix wheat and rice straw into the yellow mud and then put it on the wall, including that I use cement to make iron-reinforced concrete, and I need to add iron bars to the cement to increase the strength. The root system of the big tree in the earth plays this role." Li Ke said.

When Li Ke said this, some ministers who were not good at architecture immediately understood. Most of them looked at Li Ke in surprise. His Highness did not expect to be able to connect the principles of these completely different activities.

"These places in Guannei Road and Hedong Road are a large number of loess areas. In the past dynasties, this area is also an area where the population is relatively concentrated. Therefore, a large number of people cut down trees for farming and reclaimed wasteland. There are fewer and fewer trees in these places, and soil erosion is also increasing. It's getting more and more serious, like on some hillsides, if it was originally covered by forest and vegetation, even if it rains heavily, it will be fine."

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

"Then these streams will gradually converge into rivers. These rivers are tributaries of the Yellow River. Finally, the tributaries carry sediment and flow into the Yellow River. Sediment deposits, rivers accumulate, and the lower reaches of the Yellow River will inevitably divert! At that time, I am afraid it will be flooded, and starvation will be everywhere."

Li Ke's words are not aimless. The diversion of the Yellow River is very terrible. It is not just a few simple lines of writing in history.

Anyone who has experienced flood disasters in the past 98 years 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 breaches.

"What your highness said is very true. I was born in the Wang family of Taiyuan. On the mountain near my home, there was a small hill with many trees. I used to walk there when I was a child. There are no ravines and ravines on the mountain as your highness said. However, after the people reclaimed wasteland, 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 did the soil in that gully go? I'm afraid it all flowed into the Yellow River." Among the ministers, a middle-aged man in his 40s asked.

"Your Highness means, do we want to start planting trees in this loess area?" Duan Lun asked with a bitter face, don't think about it, this is the business of his Ministry of Industry.

"Yes, planting trees is one aspect. Let the people plant trees and take care of food in all the land that has not been opened up during the slack period!" Li Ke said simply. In this era, as long as the food is taken care of, the slack time is left to the people to deal with it. The whole family of the people is willing to come out to help, and children are free.

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

"Also, doctors from the Ministry of Industry and the Imperial Medical Office can investigate how many medicinal herbs grow in the local mountains, and the conditions for the growth of these medicinal herbs, such as some that like to grow under trees, can cooperate with the common people to plant trees and then plant them. Between the saplings and the saplings, hasn’t the Imperial Medical Bureau always had cultivation techniques for some herbal medicines? They’ve all been promoted.”