When Jingwen heard about this Zhancheng, he naturally thought of Zhancheng rice. Because it was mentioned in the middle school textbooks of later generations, a kind of rice was introduced in the Northern Song Dynasty, because it came from Zhancheng, so it is also Zhancheng rice. And this kind of Champa rice has great advantages, the first is drought tolerance, and the second is that it is born without choosing the land, and the vast majority of the land can be planted. As for the third reason, the growth cycle is short, from planting to harvesting, it can be harvested in less than 60 days.

So this kind of rice can be grown in the right place, and it can be planted several times a year. This Champa rice may be the earliest multi-cropping rice, which can increase grain production a lot. And the area of Vietnam where this Champa rice is located in later generations was also an important grain producing area in later generations. In later generations, Vietnam's rice was famous in many places, and even robbed many local Chinese rice markets. But it's a great place to grow food. Therefore, Jingwen was also tempted by it.

"Your Majesty, this Champa rice is beneficial to our Datang and not harmful, so we can introduce this Champa rice. As long as Champa rice is introduced, then we can completely use Champa rice in the south. The northern soil is hard and arid, which is not suitable for growing this rice. Therefore, in the future, we can mainly use wheat in the north, and there are many paddy fields in the south, so we can grow rice. In this way, in the future, we will have a situation in which wheat is the main thing in the north and rice is the main thing in the south. But it's all food, and it doesn't matter what you eat. Jingwen said.

The thing that Jingwen and Li Shimin talked about is to promote different food crops in different places. The north is relatively arid, so wheat can be grown as a more drought-tolerant crop. Rice is planted in the south, so that the water network resources of the upper south can also be used. After all, rice needs a lot of water, and the north was not suitable for growing rice in ancient times.

Historically, the northerners were mainly wheat, while the southerners were mainly rice, which is also the saying of northern wheat and southern rice, which is also divided according to the local environment. But it doesn't matter to the next generation. In later generations, there were also many rice growers in the north. However, it was only possible in later generations when all kinds of water conservancy facilities were complete and all kinds of agricultural equipment were excellent, otherwise it would be impossible to grow rice in the north, and even if there was a yield, it would not be very high.

And the south promoted rice cultivation, which was the case in ancient times. If you barely grow wheat in the south, you will not end up with a good harvest, but will delay things. The rice yield in the south can be said to have a great impact on the national agricultural output. Jiangnan's grain output can only gradually increase in the future, and the proportion of the country's grain output will only gradually increase, so Jiangnan must of course further increase Jiangnan's grain output in this situation. Only the development of Gangnam can be done to the fullest. Only then can the north get food back.

It is an indisputable fact that the future of the north will definitely be inseparable from the food feed of the south. Therefore, if this Champa rice can be promoted, then the south can be developed as much as possible. Isn't Datang's current development of Jiangnan just to be able to get enough food in the future? Even when the time comes, people can be relocated, so that the population pressure in the north will be reduced a lot. The middle and late Tang Dynasty in the original history can prove that the population pressure in the north, especially in the Guanzhong area, was very huge, which forced Tang Gaozong Wu Zetian to be forced to move the capital de facto.

"Can this Champa rice really be harvested in just over 50 days if it is planted? If so, is it possible to plant several times a year? If that's the case, of course it's fine. Li Shimin asked.

Jingwen said with certainty: "Yes." Not only can it be harvested in more than 50 days, but it also does not choose a place to grow, and it can tolerate drought, so this kind of Champa rice is a rare and good variety. If we can use Champa rice. Then we can grow rice two to three times a year in the Jiangnan area, so that Jiangnan can be completely self-sufficient in grain and will not rely on blood transfusion from the north. And if it goes on like this, it will only get better and better, so that the south can do its best to feed the people in the north. And as long as it can increase their food production a lot. Then the speed of Jiangnan development is much faster. As for us, we will not have to rely on the long-distance transportation of grain from the north, and we can completely produce it locally, so that they can survive on their own. ”

The Tang Dynasty period was completely different from the later Ming and Qing dynasties. Later, during the Ming and Qing dynasties, the north needed rice from the south to transport blood. However, the Tang Dynasty was different, and the northern Tang Dynasty needed to provide food to help develop the south. At present, the land in the south has just been initially developed, and the output is not very high. Moreover, the rice yield of this era was not high, and the production cycle was also very long, which could not make a large number of people self-sufficient. Therefore, the introduction of Champa rice, although it cannot increase the yield per mu at a time, can completely allow the people to grow a variety of one-season rice, or even two-season rice, so that the grain output can be increased by two to three times. Being able to increase it by two or three times is a very powerful benefit, and who wouldn't be tempted.

No one knows the truth of instability without agriculture better than the ancients, and the ancients know the importance of grain better than the later generations, so Li Shimin heard that it can increase the rice yield by two to three times, which is very helpful for the Tang Dynasty. As for the future, won't the Tang Dynasty be able to enjoy the wealth of the Li family for a longer time? Therefore, the grain output can be said to have broken the hearts of countless ancient emperors, and the low grain production and productivity are also the reasons for the demise of countless dynasties.

And this Zhancheng rice is related to the progress of the future development of Jiangnan. If there is enough place to grow Champa rice, then the development of Jiangnan will be much faster. To develop a piece of land, the most important thing is the food problem. After all, it is difficult to provide a large harvest on newly developed land, and it is necessary to mobilize grain from the north. Therefore, the harvest cycle should be shortened as much as possible, and they can be self-sufficient by planting a few more times. And once they can be self-sufficient, it won't save a little bit!

"Okay, I'll go to the Champa of Linyi Country right away, and then introduce this Champa rice. As long as this Champa rice is introduced, then my Datang's grain can increase the yield, which will of course be of great benefit to my Datang! Li Shimin said.

"The emperor is wise!" Jingwen said.

"However, Your Majesty, I still have one more idea, that is, the idea of how to deal with this Linyi country!" Jingwen said.

"Huh? What to do? (To be continued......)