Propose breeding methods.

The new type of plow that Zhang Ru mentioned was the curved-beam plow. This was a recently developed, advanced implement that had just begun to gain popularity in the Hebei region. Compared to the old straight-beam plows, the curved-beam plow was not only smaller in size and lighter in weight, but also featured an adjustable plowshare to control the depth of the furrow.

The introduction of the curved-beam plow meant that what previously required two oxen to complete could now be accomplished with just one. Moreover, its smaller size made it much better suited for working in mountainous areas, terraced fields, and other narrow plots of land.

After observing carefully for a long while, Li Zhi couldn't help but marvel at the ingenuity of the ancients. He proceeded to inspect several other commonly used iron tools, including harrows, sickles, shovels, and more. Li Zhi searched his memory for the designs of agricultural implements he had seen in his previous life. Soon, he attempted to sketch a large harrow suitable for dry fields. This harrow could be pulled by oxen or horses, leveling a much larger area of land in one go.

He then suggested a pointed, curved shovel and a digging spade, both improvements upon the existing flat-headed shovels, to make them more efficient for excavation. However, his knowledge of farm tools was quite limited, so these were the only improvements he could propose.

Even so, to Zhang Ru, these ideas were already quite remarkable. After exchanging a surprised glance with Liu Hui, Zhang Ru said, “Your Highness truly lives up to your reputation. With just a brief observation, you’ve come up with so many improvements. I am deeply impressed.”

Li Zhi replied, “You flatter me, Lord Zhang. I was merely speculating. The actual effectiveness of these ideas will require you and Lord Liu to find someone to test them.”

Zhang Ru responded, “It is currently the spring plowing season in many places. I will have these ideas tried out and, if successful, promoted as soon as possible.”

Li Zhi then turned to the main purpose of his visit: to consult Zhang Ru and Liu Hui about methods for selecting and breeding crops. His understanding of this area was not deep, but he had some knowledge from having once helped clients produce experimental instruments.

At present, the Tang dynasty’s breeding methods still mainly relied on ear selection, which meant choosing robust, full-grained plants as seed stock for the next season. This method required careful and labor-intensive selection in the fields every year.

Li Zhi thus explained some modern breeding methods he knew to the two officials. This included establishing seed cultivation bases, separating high-quality seeds from ordinary farmland, and continuously eliminating inferior varieties to purify the stock. He also mentioned the line selection method, where seeds with similar growth characteristics were planted separately under different conditions for comparison.

Then, based on their various growth traits, targeted breeding could be carried out. Finally, lines with significant value for promotion would be sown on a large scale, and the resulting high-quality seeds distributed across the country.

These ideas struck Zhang Ru and Liu Hui like a thunderbolt. Though they had spent most of their lives in agriculture, they had never considered breeding crops in such a way. Li Zhi’s methods completely broke with the traditional model of each household breeding seeds independently, instead concentrating the best varieties together. This not only allowed for superior selection through intensive cultivation but also enabled the development of strains better suited to different local environments.

Almost simultaneously, Zhang Ru and Liu Hui rose and bowed deeply to Li Zhi. Zhang Ru spoke first: “Your Highness’s wisdom is indeed extraordinary. I am utterly humbled.”

Li Zhi replied, “There’s no need for modesty, Lord Zhang. You are busy with official duties all day and naturally have little time to ponder these matters. I merely have more time to think idly.”

Liu Hui added, “Your Highness needn’t defend us. This is our duty. That we must rely on your guidance now brings us nothing but shame.”

Li Zhi said, “Lord Liu, there’s no need for that. I only hope my suggestions will be of use to you both.”

Zhang Ru, visibly excited, said, “Although Your Highness’s methods have yet to be implemented, I am confident they will yield great results. I shall immediately send people to acquire quality seeds for experimentation, hoping that by next year, we can promote them throughout the Tang empire.”

Li Zhi nodded. “Then I’ll leave it in your capable hands.”

With that, he continued, “Now that merchants from various countries frequently travel to Chang’an, I have privately purchased many crop seeds from them. One of my purposes today is to ask Lord Zhang to assign some people to supervise their cultivation.”

This was another aim of Li Zhi’s visit. Liu An had already collected quite a few plant seeds for him, but due to his limited time, he had only managed to plant cotton so far. He wanted to borrow a few personnel from the Office of Agriculture to help establish some experimental fields outside the city.

Upon hearing Li Zhi’s request, Zhang Ru agreed without hesitation. Not only would this assist Li Zhi, but it would also help the Office of Agriculture cultivate new crops for wider adoption—so why not?

The three of them chatted a little longer, and then Li Zhi took a few clerks borrowed from the Office of Agriculture back to the prince’s residence to collect the seeds.

With Li Shimin’s case concerning Li Zhi finally resolved, his previous travel plans could resume. Coincidentally, the Empress Zhangsun had been feeling down lately due to the matter of Zhangsun Shunde, so they soon left Chang’an. With the emperor and empress away, Li Chengqian was left to supervise the administration. Fang Xuanling, Zhangsun Wuji, Li Jing, and others naturally became even busier.

Li Zhi thus devoted himself to further study while focusing more attention on the ironworks. He hoped to develop some special steel as soon as possible, so he could use his knowledge of machinery to accelerate the industrialization of the Tang Dynasty.

Within the ironworks stood a small blast furnace specially used for various experiments. Li Zhi, Li Yin, and Ba Ken were currently leading a team to develop stainless steel. Li Yin was responsible for refining certain minor metal mixtures. Among the raw materials was a type of chromite ore, purchased from a Western Regions merchant. Besides Li Zhi and Li Yin, no one even recognized this ore. Even the merchant who sold it to them mistook it for ordinary olivine.

The extraction of chromium was thanks to Li Yin. Having learned many analytical methods, he was always seeking out minerals to study. It was during research on olivine that he accidentally discovered chromium.

Now, that merchant had been persuaded by Pei Mingli to become a sole supplier for Linde, and all his olivine could only be sold to Li Zhi. In addition to the Western Regions merchant, several traders from the northern steppes also supplied Li Zhi with various metal ores. All these ores were handed over to Li Yin for experimental smelting.

Li Zhi had become rather mischievous. Not only did he have Li Yin experiment with metallic ores, but also with air. He told Li Yin that substances could be classified as gases, metals, non-metals, and earths. He even assigned homework, asking Li Yin to find ways to distinguish the smallest mass that made up each substance.

In essence, he was using experiments to steer Li Yin toward the discovery of the periodic table of elements.