"Have you asked Zun's name yet?"

"My name is Zhang Chen."

"I'm Wang Jingwen."

Wang Jingwen started cooking tea as he spoke.

During the Ming Dynasty, tea was already very common and ordinary people could afford it.

Of course, ordinary families here refer to those whose family conditions are slightly better.

Ordinary farmers are still worried about three meals a day every day, so how can they have extra money to buy tea?

Chongzhen looked around and said, "Brother Wang is still a doctor?"

"I have only read a few medical books below and am quite interested, so I studied them at home."

After Wang Jingwen finished cooking the tea, he poured a cup for Chongzhen.

"The humble house is a bit simple, Mr. Zhang laughed."

Chongzhen didn't pay much attention to it, and he asked, "Brother Wang, how did you make the villagers' rice grow better than elsewhere?"

"There is no trick either. I like to plant flowers. I plant some flowers outside every early spring."

"Last spring, I found that the flowers on the walls of my house were growing very well, while those elsewhere were growing very average."

"I didn't pay attention at first, but later I found that the flowers in summer and autumn are also growing very well there, and the other places are very average."

This immediately aroused Chongzhen's curiosity, and he said, "Why is this?"

"I was also very confused at first. In order to figure out the situation, I carefully looked at the differences between several places."

"I observed it for several months and couldn't figure it out until one day, I found some white particles by the wall."

Zhang Chen suddenly remembered something, and he couldn't help but say, "Saltpe?"

Wang Jingwen was a little surprised: "Young Master Zhang also knows it is saltpeter?"

In ancient China, it was a major agricultural country, and it was not only reflected in various irrigation equipment, but also in the application of fertilizers.

Europeans did not know until the end of the Middle Ages that feces could be used to fertilize.

So much so that European cities often smell bad.

If you walk on the streets of Paris, you may have some luck and may step on a few pieces of shit.

If you are not lucky, you may have urine feces falling from the sky.

So the sanitary conditions in European cities are extremely poor and various diseases are often prevalent.

However, as early as the Spring and Autumn Period and the Warring States Period, China began to use feces.

By the Qin and Han dynasties, manure, silkworm arrows, pupa juice, bone juice, bean baskets, river mud, etc. were also used as fertilizers.

During the Wei, Jin, Southern and Northern Dynasties, in addition to using the above fertilizers, old wall soil and cultivated green manure were used as fertilizers.

The old wall soil is what Wang Jingwen mentioned here.

By the Ming Dynasty, fertilizers were even more abundant: manure, cake fertilizer, slag fertilizer, bone fertilizer, soil fertilizer, mud fertilizer, ash fertilizer, green fertilizer, and manuscript straw fertilizer were all used.

Even inorganic fertilizers are used, such as lime, gypsum, salt, brine, sulfur, arsenic, black alum, snail ash, oyster ash, clam ash, and oyster ash.

There are also miscellaneous fertilizers, etc.

In short, agriculture has made rapid progress after the Ming Dynasty.

However, since ancient times, people did not know that earth wall ash was actually saltpeter.

Moreover, not all earth wall ash is saltpeter, and certain conditions are required.

Zhang Chen did not expect that Wang Jingwen actually discovered that the earth wall ash was actually saltpeter.

If so, he further demonstrated that saltpeter can be used as fertilizer.

In ancient China, saltpeter mining and extraction were relatively mature, and it was the most mature in the world.

Saltpeter is generally used as a material for black gunpowder, or used to make ice or traditional Chinese medicine materials, and almost no one uses it as fertilizer.

But in fact, it is a compound fertilizer, that is, potassium nitrate.

Regarding this issue, Zhang Chen discussed it with Song Yingxing last year.

Beijing’s Agricultural College is actually doing the mining and application of saltpeter, and some rural areas of Shuntianfu have started trials.

Compound fertilizers such as potassium nitrate can be used directly without purification.

However, during use, you need to pay special attention, because saltpeter will burn.

Moreover, saltpeter was actually very expensive in this era and was basically used on gunpowder, which the rich nobles would use to make ice.

Very so, of course no one would think it was a kind of fertilizer.

Zhang Chen finally knew why Mr. Zhou suddenly came.

Wang Jingwen's discovery was also a big discovery.

Until that is something, you can search for it on a large scale.

"Saltpeter is naturally a very precious raw material," said Chongzhen.

Regarding agricultural fertilizers, he is actually thinking of ways.

Saltpeter was one of his considerations. The place with the largest yield of saltpeter was in the Western Regions, but now the Western Regions are not within the control of the Ming Dynasty.

Another way is to dig bird droppings on the islands in the South China Sea. The bird droppings there have been accumulated for many years, which is enough to dig for decades.

The effect of bird droppings is also very good, and it is definitely a large fertilizer library.

At this time, he rushed to the Qingjiang Shipyard to personally arrange the sea ship to go south. One of the purposes of going south was to dig bird dropping.

Wang Jingwen said: "Saltpepte powder is naturally very expensive, but if you understand it, you can find it on many earthen walls. I carefully examined it for a while and it has very unique characteristics."

Chongzhen now knew that Wang Jingwen did not invent saltpeter, nor did he find a huge amount of saltpeter ore.

His achievements are two:

1. How to identify saltpeter growing on the edge of the earthen wall.

2. Apply saltpeter to agriculture.

If people in the past knew what was going on but didn’t know why, then Wang Jingwen now solved half of the doubts that were not knowing what was going on.

This is already a big step forward.

Obviously, he could write a book about the mining and excavation of soil and salt, refine and systematically improve its methodology.

Chongzhen said: "Is this why Mr. Zhou came to you?"

"Yes, he came to me to know how I helped the villagers make the rice more plump."

"How did he know you? Nanjing is hundreds of miles away from Xuzhou."

"I don't know much about this."

"Did you tell him?"

"Well, I told him, it's nothing. When he knew it, it's a good thing to tell more people."

Chongzhen was puzzled, why did that Master Zhou care so much about agriculture?

After thinking about it for a while, he was too lazy to think about it anymore, but said, "Brother Wang, why don't you go with me, I will pay the money, you write the book, write down your method of refining the earthen wall ash and identifying the method. When we publish the book, all the money sold is you, I won't take a penny."

"This..." Wang Jingwen stood up in surprise. To be honest, he was actually writing, but it was a big problem to publish and print. He had no money and others would not care about him, a young scholar.

"How about it, come with me?"

"But the villagers need me."

"Follow me, more people need you. Believe me, not just the villagers here. I promise that your books can be promoted throughout the Ming Dynasty and let thousands of people know."

"Really possible?"

"sure!"

Wang Jingwen cleaned up and said goodbye to the villagers before dark.

The villagers did not expect that Mr. Zhou did not take Wang Xiucai with him, and Zhang Chen took Wang Jingwen away.

Everyone reluctantly said goodbye to Wang Jingwen.

After saying goodbye, Wang Jingwen followed Chongzhen all the way out of the village.

When he followed Chongzhen back to the place where the army was stationed, he saw thousands of cavalry and was shocked: "Brother Zhang, you are..."
Chapter completed!