Out of the Daesan Pass, after Gyeongju gradually entered the Lingxia Plain.

During the Sui and Tang dynasties, the Yellow River had not yet begun to flood on a large scale, and the Yellow River basin in the north was still fertile and rich.

However, there are only two truly rich places in the upper reaches of the Yellow River, one is the Hetao Plain, and the other is the Lingxia, which is the Ningxia Plain in later generations.

When Xie Yi and others entered the Lingxia Plain, it was the autumn harvest season, and they saw the vast fertile fields on the plain, and the crops that were already yellow, orange and orange were quite gratifying.

However, it can be seen that the grain production here is not high, and according to Di Zhixon, due to the climate, there is still a shortage of water far from the Yellow River, so the growth of crops is limited.

But such a harvest is placed in the northwest, which is already quite good, the people of Lingxia are relatively rich, and the supply of soldiers, horses, and military food stationed in the frontier can also be guaranteed. If there is no large-scale mobilization of troops and horses, military rations can be self-sufficient to a certain extent.

Is that satisfying?

Xie Yi couldn't help but think to himself, corn should be planted for the second time this year, and potatoes should be the same. In the future, when there are enough seeds, all of these relatively arid and barren lands will be put to good use, and food production should be even more increased.

Perhaps at that time, the grain output of one Lingxia Plain alone will be able to supply the military rations of several prefectures and counties, and it may be possible to do so soon.

In any case, corn and potatoes are drought-tolerant crops, and they are the main food crops in the northwest in later generations, and they are known for their high yield and high quality.

In addition to the farmland, you can also see some pastures, and herds of cattle and sheep walk on the green and yellow pastures, which is quite spectacular. Occasionally, you can meet a few shepherdesses, but their appearance and dress are really not flattering.

After all, it is close to the northwest grassland, and the Lingxia generation area is a mixed residence of Hu and Han, with both agricultural civilization and nomadic civilization. Canine teeth are different.

As for this land, whoever is strong will own it, and this has been the case for thousands of years.

During the Qin and Han dynasties, it fought with the Xiongnu, and was later occupied by the Xianbei people. The Sui Dynasty was occupied by the Turks in the early years, and now it is in the hands of the Tang Dynasty. After the end of the Tang Dynasty, it fell into the hands of the party. In the end, a Western Xia kingdom that dominated the northwest for many years was achieved.

Xie Yi is very fortunate that he is living in such a strong period as Datang. Of course, the strength of this period also has its own credit, and the purpose of sending Xue Yantuo is not exactly this!

Walking in the territory of Datang, Xie Yiquan should be on vacation and enjoy the magnificent rivers and mountains of Datang. At this time, the natural conditions in the northwest were okay, at least not as bad as in later generations, and there were still grass and trees on the mountains, not bare.

If you start protecting now. Perhaps the problems of desertification and soil erosion in the northwest can be effectively controlled, and the ecology can even be gradually restored.

Then the flooding of the Yellow River, which has raged since the Song Dynasty and until the Republic of China in later generations, may be avoided. If it can be promoted, it can be regarded as a contribution for the benefit of future generations and the nation.

However, it is not easy.

First of all, it is necessary to ensure that there is less war here, and it is firmly controlled in the hands of Datang, otherwise there is no protection. What about governance?

The frontier defense in the northwest has been the sorrow of the Central Plains Dynasty since ancient times.

Li Shimin proudly proclaimed that the Great Wall would not end. Trying to use the prestige of his Heavenly Khan to intimidate the northern tribes is not wrong. The construction of the Great Wall costs the people and money, and passive defense does not have much effect and significance.

It is true that the country is strong, and the soldiers are strong, so that people dare not invade, but the premise is that it is maintained all the time, and there is a wise king.

It can be inherited. Who can guarantee that the heirs of each generation will be wise? So, after all, this is not a long-term solution.

But......

How? This seems to be a bigger problem.

Don't care so much about it for now, this time you can get Xue Yantuo first, and it will be considered a success. Before leaving the Tang Dynasty, when passing through Lingzhou, you need to visit a person - Li Daozong, the king of Jiangxia County.

This prince is very famous in the romance of the Sui and Tang dynasties in later generations. It's quite a villain, but in fact, this prince is quite loyal.

Li Daozong is also Li Yuan's cousin, and has made a lot of meritorious contributions since the beginning of the Jinyang army, and was named the king of Rencheng at the beginning, and now he has been renamed the king of Jiangxia County. He is called "Xian" along with Li Xiaogong, the king of Hejian County, and is one of the few princes in the clan who can lead troops to fight.

Unlike Li Xiaogong, who is good at quelling civil strife, Li Daozong is better at defending against foreign enemies.

In the eighth year of Zhenguan, Tuyuhun invaded the Tang Frontier and threatened the Hexi Corridor.

Li Daozong first broke the enemy with a partial division and defeated the Tuyuhun army, and then pursued the Tuyuhun army fleeing south from the south road with Hou Junji and other troops.

Marched more than 2,000 miles in the bitter cold land of no one, caught up with Tuyuhun Fuyun Khan in Wuhai, broke his crowd, captured his famous Wang Xiao general, and made the Tang army win a complete victory.

In the eleventh year of Zhenguan, Li Daozong was renamed the king of Jiangxia County, but he made a small mistake, because he was once grounded in the palace because of corruption, and he was also deprived of his powers.

At the beginning of the year, because of the Du Fuwei case, Li Xiaogong, the king of Hejian County, was disgraced and thought about it behind closed doors at home after asking for guilt. There was suddenly no big man in the clan who controlled the military power, and it was not beneficial to the stability of the royal family and the balance of power.

At that time, some people speculated that perhaps His Majesty the Emperor would further reuse Li Ke, the king of Wu, but in fact it was not, but the grounded Li Daozong was released and stationed in Lingzhou.

His Majesty Li Er's move can be described as a number of virtues in one fell swoop, and under the grace, Li Daozong will definitely be grateful to Dai De and loyal to the emperor. The strength of the clan has been strengthened, the army has been balanced, and at the same time, there is a safe person looking at Xue Yantuo in the north.

It can be seen from this that His Majesty Li Er's vigilance against Zhenzhu Khan Yinan has not been a day or two, and they are all scheming!

When he was leaving from Chang'an, there was a secret conversation in the Chengqing Palace, and Li Shimin specially told him to visit Li Daozong when he passed through Lingzhou.

Of course I did, it was too necessary.

If Xue Yantuo is a little unusual, Li Daozong is the closest soldier and horse, to some extent, his own backing, and if necessary, he is still the hope of saving his life.

How can you do it without communicating it earlier? Meet and meet, emphasize the critical situation on the front line, and let the king of Jiangxia prepare earlier, so that he can provide necessary help for himself.

I think Li Daozong should be easy to speak, after all, Li Xiaogong was unlucky because of himself, and he thought about it behind closed doors. Then he made a logical comeback and was reused again.

Of course, as a famous general in the clan, Li Daozong's comeback is a matter of time, but because of himself, this opportunity has been advanced.

Based on this, how much should Li Daozong thank himself? Not to mention the grace of dripping water, at least treat yourself well, and you should always worry about more things when necessary, right? (To be continued......)