"But what's the difference?"

"It seems that the grass pond mud is darker?"

"Not only is it black, it's also smelly! It has a faint smell of grass and mud!"

"Indeed, I remember that Cao Zhang once went to the river to play with mud from the pond that was all over his pants. My mother even suspected that he had pulled his pants pockets!"

"Really? Has the prince unzipped his trouser pockets?"

"Of course not!"

"What about Marquis Shen?"

…

"Hello!"

Unable to bear it, He Yan kicked Cao Pi and Yang Xiu hard on the buttocks, which brought the topic back to the topic.

"The smell should be the smell of rotting aquatic plants."

"Yes, I heard that some farmers let some weeds grow beside the grain, and then plowed these weeds into the ground in the spring. In this way, the grain seems to be more vigorous..."

…

Even Ren Jun also joined the discussion. The three of them actually sorted out some principles with each other, which made all three of them very interesting.

"But... these rotten grass blades have disappeared, why is it still increasing food production?"

The three of them were stuck in this place and could not make any progress, and all of them frowned.

"Because the rotting blades of grass don't actually disappear."

He Yan picked up a hoe at this time, knocked hard into the ground a few times, and dug out a rotten blade of grass.

"Water, gases, and many more things we can't see, but are definitely absorbed by the crops later and promote their growth."

"Invisible things?"

"Yes, invisible things. But they do exist."

After hearing He Yan's answer, Yang Xiu pondered for a while and then asked: "Is this what Xinxue studies?"

"After removing some miscellaneous things, the essence is to study this."

Yang Xiu was a little confused: "Since you can't see it, why bother studying it?"

"If you can't see it, does that mean it doesn't exist?"

He Yan raised his head: "Power, fame, these things can't be seen, but Mr. Yang dares to say that they don't exist?"

"How many people in ancient and modern times have been studying power, but in the end it was all in vain."

"But if someone has figured out these substances that make crops grow, then this person must be like these substances. Even if he decays and withers, no one can deny his immortality."

"So, Mr. Yang understands?"

The cold wind hunted, but did not suppress He Yan's words. Everyone present clearly heard these "immortal" words.

Yang Xiu was not as relaxed as before, but his brows were furrowed tighter: "Is this the new learning?"

"This is new learning."

This kind of new learning... is different from what Yang Xiu knew before coming here.

After he chose to enter the trap, he had already read "New Interpretations of Zhouyi" and "Mencius".

These two books are indeed remarkable, and their core "investigation of things to achieve knowledge, and the integration of knowledge and practice" is even more wonderful. However, in Yang Xiu's opinion, compared to its academic value, its political value is obviously more.

But what He Yan said today opened a new door for Yang Xiu.

"Only this kind of knowledge can be defined as new learning!"

If Yang Xiu just wanted to stay in the new learning pit before, now he wants to dig deeper!

He Yan was filled with pride when he saw Yang Xiu like this.

Seeing Guo Jia slip away before, He Yan still had some doubts about his ability to sell ships and felt that smart people are not easy to fool.

But now it seems...that's not the case!

Cao Pi also moved over very suspiciously: "What's new?"

"It's a very new thing. I'll teach you when I get back."

…

Yang Xiu then returned to the issue of pond mud: "How can we find this invisible substance that Marquis Shen said can increase grain production?"

"practice."

“Lots of practice!”

He Yan gave the answer.

"Until you discover the rules, you can only practice."

"Just like the celestial phenomena deduced in the "New Interpretations of the Book of Changes", if there were no historians recording celestial phenomena for hundreds or even thousands of years, it would be difficult for us to know what the truth is."

"If the previous task was to "investigate things to gain knowledge," then the next step is to truly "unify knowledge and action."

He Yan said seriously, but he began to chuckle in his heart: "Except those who are cheating!"

Now He Yan wants to help China activate its first cheat!

As for whether he will dominate the entire server or be banned in the future... it all depends on fate.

"Other things require practice, but about the grass pond mud, I actually heard it from a friend of mine."

He Yan finally revealed the real purpose of calling Yang Xiu and Cao Pi: "You can use the decomposition method to make manure!"

The substance Yang Xiu mentioned can be obtained by retting, fermenting, and decomposing human or livestock feces.

The field soldiers under Ren Qi brought up the excrement that had been prepared early and placed it at the feet of Yang Xiu and Cao Pi.

The strong smell made the two young masters almost faint, and Cao Pi even slipped away.

Yang Xiu covered his nose and said, "Marquis Shen, can this really make something the same as grass pond mud?"

Yang Xiu and Cao Pi now sincerely want to say sorry to the grass pond mud.

Compared with these feces, how can that grass pond mud smell? It is obviously very fragrant!

He Yan did not give the answer that Yang Xiu had affirmed, but said: "You will know after you try it. Could it be that Mr. Yang has forgotten the new eight-character formula he learned."

"Studying things to achieve knowledge, can knowledge and action be unified?"

Yang Xiu slowly put down the hand covering his mouth and nose: "Marquis Shen, what should I do?"

"Simple!"

What He Yan wants to teach everyone is the "simmering dung method".

If it's a bit more indecent, it can also be called "burning shit"...

The method is to mix dung with mud and build a hollow mound.

After that, firewood is put in the embers to burn, so that there is heat all around.

In this way, through this method of "mixing mud and burning it to detoxify heat", you can make manure that can be used for fertilization.

Easier said than done.

Especially the first step, mixing the dung and soil together creates a huge psychological barrier for people.

Yang Xiu stared at the pile of excrement, which made him feel sick to his stomach but still couldn't stop.

"Mr. Yang! The unity of knowledge and action! The unity of knowledge and action!"

He Yan was very considerate and offered cheering services to Yang Xiu. After some struggle, Yang Xiu finally reached in.

"Ugh~~~"

Yang Xiu was still fine, but Cao Pi, who had been standing by, actually vomited it out first.

"He Yan! I want to go back!"

Cao Pi had already backed down, saying that he simply couldn't do it.

"oh."

Cao Pi originally thought that He Yan would use ten thousand ways to make him stay, but to his surprise, He Yan actually agreed to let him go?

"You go back. Anyway, you will just sit there and study when you go back. It's up to you."

"..."

Cao Pi was really confused.

Reading or playing with shit?

It’s so hard to choose!

After hesitating for only a second, Cao Pi came to Yang Xiu's side and inserted his hand fiercely!
To be continued...