Fertility meant spiritual energy; a lack of fertility meant a lack of spiritual energy. To make up for it, you simply added spiritual energy. Thus, the fertilizer of the Primordial World was any treasure rich in spiritual energy.
There were many such treasures, and Jiang Yuan had some on hand, such as Living Soil. A single grain of Living Soil could immediately restore the spiritual energy in the earth to normal levels.
But after thinking it over, Jiang Yuan decided against using it. Instead, he ground Fierce Beast bones into powder and scattered them over the fields as fertilizer, replenishing their spiritual energy that way.
Living Soil was excellent, but not everyone had it. Fierce Beast bones were different. Though they contained less spiritual energy than Living Soil, anyone could get their hands on some with a little effort.
Once Grain had been cultivated, Jiang Yuan would surely spread it throughout the world. And as Grain came to be planted on a large scale, the problem of depleted spiritual energy in the soil would naturally follow.
Crop rotation could solve the problem, but it would only treat the symptoms, not the cause.
Since Jiang Yuan had thought of this, he might as well go all the way and develop fertilizer too, completely solving the problem of depleted spiritual energy in the soil.
Fierce Beast bones didn't contain much spiritual energy, but spreading more of them around would be enough to support one crop of Grain, and that was all he needed.
It would simply be more trouble later on: spread fertilizer once for every crop. But compared with the harvest, that little bit of trouble was nothing.
After solving the problem of depleted spiritual energy in the soil, Jiang Yuan continued experimenting. Yet it didn't take long for a new problem to appear.
This new problem was even more serious. When the next crop of Foxtail Grass ripened, Jiang Yuan inspected it and discovered that its fruit contained a faint trace of baleful aura alongside the spiritual energy.
There wasn't much of it, but it was a bad start. If he couldn't solve the problem, the baleful aura would surely build up with each round of cultivation, eventually ruining the entire experiment.
Even if Grain carrying baleful aura could be cultivated, it would be meaningless.
"It's the Fierce Beast bone powder!"
How could baleful aura have appeared out of nowhere? Jiang Yuan only had to close his eyes and think for a moment to guess the cause: it must have come from the Fierce Beast bone powder.
After all, that was the only thing in the entire experiment that carried baleful aura.
"Could it be that Fierce Beast bone powder really isn't suitable as fertilizer?"
Jiang Yuan frowned. It wasn't that he was dead set on using Fierce Beast bone powder as fertilizer. It was just that only by choosing it could he earn Merit. Other treasures would work just as well, but they wouldn't give him any Merit.
Using Fierce Beast bone powder as fertilizer would not only increase the value of Fierce Beasts, but also create demand among cultivators, making them all the more eager to hunt them.
That way, he would help suppress the Fierce Beasts and naturally earn Merit.
Could other treasures offer the same benefits? So, as long as there was any chance, Jiang Yuan was unwilling to give up on using Fierce Beast bone powder as fertilizer.
"Remove the baleful aura before grinding the bones?"
Looking at the Fierce Beast bones swirling with baleful aura before him, Jiang Yuan pondered. Since the baleful aura was the spark that had set everything off, wouldn't grinding it away beforehand solve the problem?
The idea made sense, but it raised a new problem.
Eradicating the baleful aura from Fierce Beast bones wasn't difficult; all he had to do was boil them in water with spices. But that could only remove nine-tenths of the baleful aura. The remaining tenth wouldn't come off and required another method.
But using another method would increase the cost. That extra expense was completely unnecessary. Rather than going to all that trouble to remove the baleful aura, he might as well switch to another treasure. It would save time and effort.
Simply put, using Fierce Beast bone powder as fertilizer had been nothing more than Jiang Yuan's wishful thinking.
It offered no real advantage and could easily be replaced. A little searching would turn up a whole host of spirit materials that could take its place.
Even if Jiang Yuan did everything he could to promote this kind of fertilizer, it would be hard for it to make much difference. No one would be willing to accept it.
"I was thinking too simply. At this point, my only hope is the Creation Jade Disk."
Seeing that he couldn't think of a good solution, Jiang Yuan took a deep breath and decided to cheat.
Creation Jade Disk, give me an upgrade!
As soon as the thought crossed his mind, the Merit within him began to burn, transforming into a tremendous force that poured into the Creation Jade Disk and swiftly awakened it.
The next moment, Jiang Yuan once again entered the Daluo Perspective. His gaze seemed to see through the river of time and discern the countless futures ahead.
It wasn't just an illusion. He truly had seen the future. Among countless possibilities, he found the solution.
Merit!
Use Merit to cultivate Foxtail Grass until it transformed into Profound Yellow Grain. Then there would be no need to worry about baleful aura corrupting it. Even baleful aura could be absorbed by Profound Yellow Grain and turned into nourishment.
And dispelling baleful aura was itself a meritorious deed. The more baleful aura he dispelled, the more Merit he would gain.
Profound Yellow Grain could absorb baleful aura—that was dispelling baleful aura. So it wasn't an ordinary crop, but a meritorious crop.
Feed it baleful aura, and its fruit would contain not only pure spiritual energy, but also a trace of Profound Yellow Merit.
What was Merit? The source power the world yearned for.
That alone meant Jiang Yuan didn't need to promote it at all. To make sure the fruit of Profound Yellow Grain carried Merit, people would use Fierce Beast bone powder as fertilizer of their own accord.
For aside from the Wu Clan and Demonic Cultivators, Fierce Beasts carried the greatest amount of baleful aura.
"Gasp, is this the power of the Daluo Realm? To see through the future, rule out every possibility of failure, and go straight to the right answer."
"This..."
Jiang Yuan could barely contain his excitement. Sure enough, copying the answer was a thrill.
Now that he had the right answer, what came next was simple: he only had to copy it. He could keep using Fierce Beast bone powder, but he also had to add an equal amount of Merit.
He would keep cultivating the crop this way until the Foxtail Grass seeds had fully adapted to the power of Merit and absorbed it into their essence, passing it down from generation to generation.
Then they would naturally transform, evolving into the meritorious crop, Profound Yellow Grain.
This process took a full century. Fortunately, Jiang Yuan had plenty of Merit, or he wouldn't have been able to sustain it. Even so, the Merit he had accumulated over several centuries was nearly exhausted.
He had originally hoped to use that Merit to attain the Creation Heavenly Immortal Dao Fruit, but now that was out of the question.
Still, Mu Jiao and Xuanshan Clan had collected quite a lot of Nine Sons' Essence Blood for him over the past century, helping him condense the Nine Sons Incarnation.
At this point, Jiang Yuan only had to fuse the Nine Sons Incarnation into one to attain the Creation Heavenly Immortal Dao Fruit.
There was no rush. Cultivating Profound Yellow Grain was more important.
After a century of painstaking cultivation and pouring in vast amounts of Merit, after countless experiments, Jiang Yuan's efforts had not disappointed him. Profound Yellow Grain had succeeded.
Its fruit was plump and round, a deep, yellowish brown, and about a third the size of a grain of rice. Each plant yielded roughly three thousand six hundred grains—a truly impressive harvest.
As its name suggested, the power contained in Profound Yellow Grain was not innate spiritual energy, but the higher-grade Profound Yellow Qi.
It was the source energy of heaven and earth, second only to Profound Yellow Merit. It was even useful to those in the Quasi-Saint Realm.