Li Shimin thought of a convenient road that allowed him to go to Shanyang, but he didn't think about what it would be like when such a road network was rolled out across the country, so Sun Xiangfu needed to remind him that the matter of building roads was quite expensive, and the Wang family took five million yuan to build a road, but there were still ten roads, a hundred roads, waiting for the imperial court to take money to repair it!

At present, the most urgent need to build, is the road from Luoyang to Shannan Road, once this road is built, then the output of the entire Shannan Road to Luoyang, Guanzhong, or Guanzhong's goods, go to Shannan, flow to the entire Yangtze River basin by water, it is much faster and more convenient, with a thousand miles of land, save thousands of miles of waterway, its significance, it is equivalent to the railway hub Zhengzhou and the waterway hub Wuhan in the later generations quickly through the same.

This kind of large expenditure of millions of yuan at every turn, the imperial court can't start many at the same time, so after Sun Xiangfu gave the example of this road, Li Shimin suddenly felt that after conquering the surrounding Siyi, there were still many things to do, and if you want to do these things, the court's finances and taxes are not very rich!

After Sun Xiangfu's several suggestions, Li Shimin immediately had a lot of confidence in the overall political development of the country, and asked again, "Shicai said that he wanted to speed up the construction of education, but Zhengming said that he would be under great pressure, what does this matter have to do with it?" ”

Sun Xiangfu spread his hands and replied, "Your Majesty, labor!" As soon as free education is implemented, there will inevitably be more labor force who will enter the college to study, we Datang, how many people can be left? Without food, and the output of all kinds of crops, all of this will not be possible. ”

In any case, the farming of the Tang Dynasty is the strongest Tang in the world, due to the general low productivity of this era, and only the Han people in the Central Plains can rely on farming to solve their own food and clothing problems.

Why did the Turks keep moving south? Why do the Tibetans have to come down and rob? Why did Goguryeo keep trying to rob the Central Plains?

The ambition of the rulers should be in the minority, and the fundamental problem is that their output cannot support themselves, and life is too hard.

Now, most of these places are under the rule of the Tang Dynasty, like Xue Yantuo, every year from Shanyang, get hundreds of thousands of stones of grain over, Goguryeo, that is a big hole of millions of stones, Tuyuhun, the party departments, the land of Yunnan, are not small holes, as well as the population growth within the Tang Dynasty, but don't doubt the reproduction ability of this nation, as long as there is no war, the economy is good, they can have children, the consumption of food in the future will increase significantly, but the people who can farm the land are greatly reduced, This social issue was only thought about by Sun Xiangfu alone, and he had talked about it to Empress Changsun once, and now, he had to talk about it again with Li Shimin and the others.

After Sun Xiangfu finished telling them this question in detail, Li Shimin, Fang Xuanling and others were stunned, it turned out that after the country of Datang became bigger, the situation became much more complicated, and if you want to govern it well, you already need to stand at a higher height.

Feeding more than 10 million people and feeding more than 30 million people are completely different things, which requires two to three times the increase in productivity to solve, and it is even more difficult to make rapid progress in all aspects while suddenly feeding so many people, so Sun Xiangfu finally said, "Your Majesty, please go to Shannan Province next year to conduct new crop research to meet the new needs of my Datang in agriculture." ”

"Going to Shannan Province to research new crops?"

"Yes, several fields have been built around the Dongting Lake area of Shannan Province this year, this kind of fields are most suitable for growing rice, and the minister plans to conduct research on rice planting to make its yield like wheat, and get a big increase, so that we can use less manpower to feed more people."

"Are you sure?"

"There are still some."

"In this way, I will transfer you to the head of Shannan Province next year, and it just so happens that you will complete all the road construction and farming over there."

"Obey."

In fact, here, what Sun Xiangfu wants to say, has already been said, however, Li Shimin has no intention of letting him go, this year is coming to an end, next year, there are two major events in the imperial court, the first is that the world's first sports conference will be held in Dingxiang, which will be an unprecedented event, and in the second half of next year, the five county-level cities of the Anbei Metropolitan Protectorate will basically be completed, and it is time to revoke the Anbei Metropolitan Protectorate.

The second major event is the second imperial examination to be held in Datang, after three years, it also happens to be the third year that Datang will promote education to the county level, and the number of students in various places should be much more than three years ago, which is related to the promotion of the entire construction of Datang in the future, and it is also the top priority.

On these two matters, Li Shimin asked them a lot of opinions and made a lot of his own requests, until late at night, when the wine on his body was gone, he let Sun Xiangfu and others go home.

Yu Xiu'er tonight is very enthusiastic, even if it is late at night, there is no intention to let Sun Xiangfu rest immediately, Sun Xiangfu knows that the matter of giving birth to a child has been put on the agenda by her again, so young, it has been mixed to the point of three dukes, the number of sons is not as much as Enyin's title, let the emperor knight the unborn child, this is too embarrassing, it is a dereliction of duty for her hostess!

So, when Sun Xiangfu got up the next day, he wanted to write a letter to Zhang Gongjin in Pyongyang, asking him to help collect wild ginseng, tiger whip and deer whip Northeast specialties to replenish his body.

To get back to the point, the purpose of his letter to Zhang Gongjin is to let them closely monitor the Wa State, if there is a chance, he will be a guy, it is best to take the opportunity to take the Wa State, Datang is short of labor! It just so happens that the Japanese country has a population of hundreds of thousands, so you don't need to use it in vain!

Moreover, he also sent a letter to Li Ji, the governor of Ningchuan Province, and provided him with some suggestions that could help his subordinate army go to the plateau, and asked him to find someone to explore slowly, which was something that Li Shimin put forward after discussing with them last night, because the Wa State and Tubo did not send envoys to submit to the Tang Dynasty before this court meeting.

Of course, what they didn't know was that the Japanese did send an envoy, but not long after the ship went to sea, it was hijacked, and then the unfortunate Japanese envoy was beheaded and thrown into the sea to feed the fish.

As for Tubo, after receiving the news of the disastrous defeat of the army in Guanzhong, the young and vigorous Songtsan Gampo couldn't wait to take revenge on Chang'an with a knife, how could he be a minister! Anyway, Datang can't beat him, and he still needs to send tens of thousands of troops to defend him, he just waits for Datang to waste troops and food around the plateau in vain, and find him to negotiate peace when he can't hold back, in addition, he also plans to take the remnants of tens of thousands of troops down the plateau to rob some people, he can't afford to provoke the Tang army, and the people over there in Tianzhu should be easy to bully!

In fact, it can be known from some historical records that in the early Tang Dynasty, the level of the army in Tianzhu was scummy, Wang Xuance borrowed thousands of soldiers in Tubo and Nepal alone, and defeated the tens of thousands of troops of Magadha, one of the four major countries in the Tianzhu region, at the same time, it can also be seen that during this period, the population of Tianzhu area did have a lot, and a country had tens of thousands of troops, so the population was at least hundreds of thousands.

It is precisely because of these plundered population bases that the subsequent war between Tubo and the Tang Dynasty often dispatched hundreds of thousands of troops, and the famous Battle of Dafeichuan, Tubo dispatched 400,000 troops, almost annihilating Xue Rengui's entire army.

For Tubo, Sun Xiangfu and Li Shimin are vigilant enough, because, Sun Xiangfu, who has watched many TV series in later generations, knows that since the Gaozong period, the Tang Dynasty and Tubo have been using troops almost year after year, fighting for more than two centuries, and even after the Anshi Rebellion, Chang'an was once captured by Tubo, until the end of the Tang Dynasty, the two countries were defeated together.

Such an opponent naturally wants to study him earlier, and then get rid of him, without its existence, let the Tang Dynasty control the land of the Western Regions for more than two hundred years, where will so many things happen later.

Of course, the role that Sun Xiangfu can play is to prompt the direction of fighting altitude sickness, and some specific things have to be handed over to Li Ji to explore by himself, and Shanyang Medical College will also start to study some Tibetan medicine to see if it can help the army.

After writing the letter, Sun Xiangfu set off for Weinan to catch up, and after arriving last night, he added one point, that is, Datang's monetary policy, with the current trade volume of Datang, it is time to formulate a currency rule for the whole world.

In fact, the highest level of money is the credit standard of paper money, but, this thing, in ancient times, is difficult to operate, first of all, the statistics you are not good to do, once there is something faint, lack of money and random hair, then, the entire economy may have a big collapse, and, at the beginning, it is not so easy to win the trust of others, so, now, still have to choose the gold, silver and copper standard.

After determining the gold, silver and copper standard monetary policy, it is necessary to standardize its management, with the current market price of Datang, one tael of silver, almost worth the same money, and one or two gold, almost worth ten yuan, the circulation of the market, mainly copper money.

After the new standard management system was established, it was different, silver and gold could also be used as currency, but before use, you had to smelt and mint them into fixed coins of consistent purity through the official mint, and private silver taels and gold of different purities could not be circulated in the market.

Sun Xiangfu came to Weinan in order to let the smelting workshop here make a set of models for minting coins, not only the gold and silver currency needs to be standardized, but the style of the copper coin must also be remanufactured, because Sun Xiangfu proposed a plan to print the portrait on the coin, so that everyone who uses Tang money knows what the emperor of the Tang Dynasty looks like, Li Shimin just made up the picture a little, and nodded and agreed.

In this way, when Tang money began to circulate in the whole world, who in the world did not know you? It's politically significant!