The Tang and Song dynasties are an important part of China's historical development, but the Ming and Qing dynasties are also considered to have developed to a very high degree in all aspects.

The Ming Dynasty was very high in all aspects, and the Qing Dynasty had a certain degree of regression, but with the high-pressure policy of the Manchu Qing Dynasty, after popularizing the high-yield crops from South America, even if there was more dissatisfaction with the Qing Dynasty, it had to be determined that during the Qing Dynasty, the population growth far exceeded that of other historical dynasties, from the peak of more than 100 million people, to the Republic of China period, 450 million, after this population base, after the establishment of the reputation of the first country in Chinese.

In feudal society, there is no family planning, of course, people want to have as many children, how many children, in the history of the entire feudal dynasty, the population has fluctuated regularly, and the sentence written at the beginning of the Romance of the Three Kingdoms has also become a wise saying.

The feudal dynasty, no matter how holy it is, no matter how hard the emperor tries, there is a dead knot that cannot be avoided, that is, the magnates and the landlord class gradually accumulate land, when the land annexation reaches the limit, and the remaining land cannot feed the entire people, there will inevitably be civil unrest.

People can't live, but they won't die silently, they will fight, they will rise up, which causes turmoil in the dynasty, maybe the peasants revolted, unable to occupy Zhengshuo, and became the emperor, but it dealt a heavy blow to the power of the kingdom, so that this feudal dynasty faced disintegration.

In the middle, the development of the Northern Song Dynasty was a peak, with a huge territory and vigorous commerce, which created the glory of the Northern Song Dynasty and made the population rise on a large scale, even exceeding 100 million.

Taking the cultivated area of the Northern Song Dynasty, almost 800 million mu of cultivated land, if all the grain is planted, according to two seasons or one and a half seasons to calculate, a total of about 4 stone output, calculated, the country is about 3.2 billion stone, a person per year 10 stone of grain, the limit is about 320 million people.

The per capita is unbalanced, there are few people, there are many people, it is impossible for all the grain to be used for food, and it is even more impossible, all the land is planted, and it is also necessary to consider cash crops and others.

That is to say, under the premise that everything is stable, at most 200 million people, is the limit of the development of the Northern Song Dynasty, which has nothing to do with anyone being the emperor or anyone being the prime minister, which itself is determined by the supply and demand relationship between food and people.

The traditional feudal dynasty, to the Northern Song Dynasty, should be the ultimate in development, but it has changed in the Qing Dynasty, which is also what some people in later generations advocated what Kangqian prosperous, to be honest, the level of governance of the Manchurians, just like that, Kangqian compared with the traditional wise monarchs, at most a middle-aged posture, but on the contrary, they obtained an artifact.

Sweet potato, corn, and potatoes, in fact, were gradually spread during the Ming Dynasty, because this diet is a foreign product, a traditional practice, and it is impossible to bring out the taste of the three foods, plus they are more or less sandy, there are some problems, in fact, it is not easy to promote.

Some famous doctors in the Ming Dynasty, once recognized the problem of food shortage when the climate of the chaotic Xiaoice River in the Ming Dynasty was strong, and began to promote sweet potatoes, but the effect was not good.

Sweet potatoes can be satisfying, but if you eat too much, it is also easy to cause problems, for example, sweet potatoes with more fiber are a huge burden on the stomach and intestines, and these grains need more oil to be delicious, otherwise, the taste is very bad.

The Qing Dynasty had a unique opportunity, when the war subsided, the climate of the Xiaoice River also just passed, and there were massacres and high pressure in the early days of foreign rule, this policy coupled with the war and peace, in the end, the most difficult promotion of sweet potatoes, corn and potatoes, just like this, even the Manchu Qing did not have any policy at that time to promote the mass cultivation of these three plants, but in the end, it became a fait accompli.

Food in the feudal society, directly determine the population, with more food, can feed more people, without any moderation, in the face of the rising population growth rate, up to 100 years, can increase several times, which is also the fundamental reason for the population surge in the Qing Dynasty.

In the Ming and Qing dynasties, China's crops have undergone development, began to be dominated by wheat and rice, and as two auxiliary cash crops in the north a year, cotton stands out among many cash crops and has become the most important cash crop.

The existence of war may allow Japan to gain a lot of benefits, but what really makes Japan rise is all kinds of light industry, especially during the First World War, when all the developed countries were dragged into the quagmire by this unprecedented huge war, Japan and the United States took the opportunity to rise, occupying the commercial share that these developed countries could not take care of.

In the middle, Japan, as an island country, would not be able to make so much money without the backing of various mineral materials throughout China, and there would be no way to achieve large-scale production without enough raw materials.

For Dingjun, now a huge problem is in the raw materials.

In the Northern Song Dynasty, although cotton has appeared, it is the cotton of the Western Regions, which is commonly known as grass cotton, and the cotton that really flourished in later generations is actually Indian cotton.

Called grass cotton, the Western Regions cotton, their fiber is not long, because the plant is relatively short, they are not only not high quality, the yield is not high, there are also people spinning and weaving, but it is not the mainstream, this era, or hemp-based, cotton has not become a cash crop, maybe sporadically used, but not very much.

Zhao Xin had already noticed this thing, and when he was in the Daimyo's Mansion, he searched for traces of cotton through merchants, and also found some sporadic cotton producing areas, mostly concentrated in the southern region.

In fact, in the south, because of the relationship of the Maritime Silk Road, the Middle East, India and China are still very close, cotton passes through here, sporadically into China, has not yet bloomed, but in some regions, it has also become one of the specialties.

The industrialized textile industry, scale is the key, no matter how high the efficiency is, the raw materials are only enough to produce hundreds of horses, and your efficiency is high, and the raw materials to support the industrialization of cotton cloth are at least at the scale of 10,000 tons.

With the population of the Northern Song Dynasty, 10,000 tons of cotton, it may be able to make 15 million pieces of cloth, which is not even the entire Northern Song Dynasty market, and the demand for cloth is a rigid demand, 15 million horses, maybe 10 people share a piece of cloth.

But even if it is 100,000 tons of cotton, it also needs a huge planting area, generally speaking, the cotton output of later generations, may only be three or four hundred catties, this is not lint, the textile industry needs to be treated lint, ordinary cotton, after treatment, is lint, to several times to transform one.

100,000 tons of lint, with the initial output, may require millions of acres of land to grow cotton.

Even in the 21st century, the promotion of improved varieties is not one or two years to complete, there must be pilots, promotion, support from top to bottom, to be able to do all this in five years, it is not easy.

In the recitation, it is even more difficult, I am afraid that now, Zhao Xin began to promote the development, if you want to get enough raw materials, it is not possible to do it overnight, as short as ten years, as many as twenty or thirty years, which requires continuous efforts to do.

Before the development of the chemical industry to a certain extent, cotton was the foundation of the textile industry, without cotton, even if Zhao Xin knew a lot of advanced looms and spinning machines, it was impossible to build a large-scale cotton textile industry.

As for traditional Chinese silk weaving, even in the 21st century, large-scale silk weaving machines cannot be used on a large scale.

Silk has many advantages, but compared with cotton fiber, the strength is not good, unless the silk is fixed to a lot of degrees, so that the silky advantages of silk can not be brought into play.

Of course, it has entered the stage of CNC weaving, and the machine has many advantages in the weaving of silk, but this is too far away for Zhao Xin.

In terms of materials, because of the strength of the card system, even in an environment like the Northern Song Dynasty, it can reach the level of the 21st century, or the middle of the 20th century, but the microelectronics industry, the accumulation in the middle is not something that can be provided in a short time.

The Northern Song Dynasty has not even reached electricity now, and even if it enters the era of electricity, there is still a long way to go from microelectronics and semiconductors.

Of course, at all costs, you can still do it, and even don't choose tubes and transistors, and go directly to semiconductors, which will come faster.

The biggest problem restricting semiconductors is the yield rate, which is in front of the replication of the card system, as long as there is a yield rate of one percent, you can promote the gradual expansion of semiconductors, the cost of semiconductors is because of the yield rate and huge investment in it, when this is replaced by cheap copying, as long as it is the most primary manufacturing, and then gradually strengthen the accuracy, you can quickly improve.

But that is also a basic theory and the first semiconductor to be produced, Zhao Xin now, unless it is with the help of the lottery of the card system, lucky to draw semiconductors, relying on the current technology of the Northern Song Dynasty, the possibility of manufacturing is basically zero, and even from now on in this direction, preparation, it is not one or two hundred years can produce much effect.

In the case of the current navy, when the foundation of the ironworks has been laid, as long as it develops steadily, takes the road of the navy, and then popularizes thermal weapons, it can almost beat the whole world, including the Northern Song Dynasty, these more advanced things, perhaps in their lifetime, will leave some relevant knowledge, or simply just imagine the same idea, but these will inevitably save China hundreds of years of time in the future.

Of course, if you really want to choose, the Northern Song Dynasty still has a huge number of projects, that is, hemp, hemp is the mainstream fiber crop in China before cotton textile became the mainstream, and hemp clothes have also become the clothing of civilians at a low price.

Regarding hemp, after hemp was replaced by cotton, it has become a niche thing, relying on the return to the basics, and there was also a period of linen that was popular, but it was only a trend, and it was soon replaced by other more trendy things.

Knowing what to be eliminated, Zhao Xin didn't want to get involved in this field, because what he remembered, the cotton textile machines of the industrial revolution, those were mainly cotton textiles, relying on this idea, it is not impossible to develop hemp textiles, but this is tantamount to a waste of time.

From a technology, from the emergence to the perfection, with Zhao Xin's half-understood understanding of hemp textiles, it may take three to five or seven years, in this time, Zhao Xin has found a large number of cotton seeds, and the initial promotion.

The difference between cotton and hemp, that is heaven and earth, history has proved this with indisputable facts, for three or five years of profits, but to go against the general trend of history, this is not a mantis arm as a car, Zhao Xin is to study history, of course will not be such a brain-dead choice.

In fact, now Zhao Xin can carry out, there is a huge project, in the daily necessities industry, the daily chemical industry in the future, is also a huge industry, whether it is a washing as the theme of the soap industry, or a petrochemical industry based on petrochemical products such as plastics, are an important pillar of daily necessities.

It turned out that Zhao Xin was also quite actively involved in the daily chemical industry, in Miaojiazhuang, two projects to earn the first pot of gold, a steamed bun, using soda ash, a soap, is the product of saponification reaction, under the premise that the three acids and two alkalis have been completed, the chemical industry, as long as a little in-depth research, can obtain a huge harvest.

For example, on the basis of soap, we have developed shampoo, hand soap, and various washing products, for example, on the basis of three acids and two alkalis, we have improved other chemical products, and we have tried to crack petroleum and develop petrochemical industry in the first place.

This itself is a natural climbing science and technology line, but because of the accident in the steel plant, it was suspended, three acids and two alkalis, all are corrosive, in the chemical conversion, there will be a lot of chemical reactions, most of the chemical reactions, are accompanied by light, heat, violent reactions and gas volatilization.

The danger in the middle is even higher than that of the steel plant, some corrosive gases, or toxic gases, because of misoperation, once an explosion occurs, the danger is enough to erase a city.

Under the premise that there was only such a foundation as Ding Haijun, Zhao Xin did not dare to act rashly, except for the original soap industry, the pace of chemical development was stopped, and the original industry began to shrink, forming a small laboratory factory, in which experience was accumulated, and as for large-scale expansion, it would not be carried out until the occupation of a larger island.