The reason why Guo Yuan didn't think of using elephants to plough the land at first was because when he first came into contact with domesticated elephants in Nanzhong, it was only the end of November, and it was not time for spring ploughing.

But after more than a month of driving elephants to level the terraces and smooth the road, as Li Su also found that the elephants' obedience was of great use, more attempts to drive the elephants were launched.

After this idea, Li Su immediately recruited the craftsmen in the camp, including carpenters and blacksmiths, and asked them to build a plow that could be used by elephants.

And what Li Su didn't expect was that in this process, the structure of the traditional plow was optimized, and even the technology of the ox plough could be fed.

Here's what happened, in the second half of the month, when Li Sugang ordered this task, the craftsmen only tinkered for three or four days before making the first version of the "elephant plow" in their minds.

When Li Su saw that thing, he was immediately startled - because the craftsmen were very simple and rude, and directly magnified the size of the ox plow by three times.

After all, the weight of a large elephant is close to ten times that of a strong ox, so the length, width and height of an elephant are two or three times that of an ox.

The problem is that the plough or the straight plough of the Han Dynasty for the ox was not formed until the Sui and Tang dynasties, and the common use of the straight plough is that two oxen frame a plough and only one ploughshare in the middle.

In fact, Li Su has always been very unhappy with the operation method of "two oxen and one plow" of the straight plow, because he has seen farmhouses in later generations, and knows that the modern farm plow has long been a plow pulled by an ox, and a plow has several ploughshares, which can turn over several layers of soil at the same time.

It's just that because Li Su was not diligent in his previous life, he didn't distinguish between grains and grains, he had never done farm work and never lived in the countryside, and his understanding of agricultural tools stayed at the level of glimpses of farmhouse tourism.

So although he has always felt unpleasant, he didn't feel that he had to improve, and he didn't know the professional term "Quyuan plow", he didn't know how to change it, and he vaguely thought in his heart that "two oxen pulling a plow may be able to run twice as fast, and it won't be much more efficient."

But on the eve of Chinese New Year's Eve, when he saw the craftsman make an elephant plough from a straight ox plough that was directly magnified three times, Li Su couldn't bear it at all—because when the craftsman demonstrated, two elephants were needed to carry such a heavy plow, and then only plough the middle of the soil.

This is outrageous! How inefficient! The original purpose of using the elephant plough is to fancy the elephant's strength, which can drag many rows at one time, and you can drag an enlarged version of the nine-tooth nail rake is stronger than this broken thing!

Moreover, the elephant's legs are too thick, and the place where it has walked has long been trampled on, so the elephant must not go backwards or turn back when ploughing, otherwise it will be in vain. The straight elephant plough ploughs one row at a time, which means that when plowing the second row, because the row spacing is too narrow, the place that has just been ploughed will be stepped on by the elephant again, so what is still a fart?

Li Su directly sent back the simple and crude version of the test item: "This can't be used, completely redone!" Don't let your imagination be limited by the kind of broken plough that oxen currently use, think boldly, and I want to make sure that there is no compromise on two principles:

First of all, the elephant plough must be pulled by one elephant, don't do two elephants to carry one plow. Secondly, the elephant plough must plough several rows of land at a time, and the final width of the plough should be much wider than the width of the elephant's body, so as to ensure that the elephant will not repeatedly go back and re-step on the soil when ploughing other fields. ”

When they heard these two specific indicators, the first reaction of the craftsmen was to complain, and several senior blacksmiths and carpenters told Li Su:

"Governor, what you said is simply impossible, since ancient times the plough has been carried by two oxen, how can one ox plough several rows of land. Not to mention whether the ox is strong enough, at least you have to put all the ploughshares of the plough on the iron head, otherwise the sharpness of the wooden ploughshare and the pull of the ox and horse can not break the soil at all, and it cannot be broken deeply, unless the ploughshare is narrower and the soil is less shallow. ”

The craftsmen first said a lot of ready-made difficulties, and Li Su couldn't refute them directly, after all, he was not professional.

So Li Su chose a relatively simple and crude method: "I don't care how you put the plough on the animal now, in short, I want to be able to balance it on a single animal." There is also the angle of the ploughshare drooping and entering the soil, which must also be adjusted, and the livestock should be lifted up if it is high and shallow into the soil, and pressed down when the livestock is short and deep into the soil.

Can't do this little thing? I will give a total of 30 catties of gold and 30 hectares of land to the craftsmen who solve this problem, and when the time comes, you will each share according to your merits and contributions. It is also possible to divide labor and cooperate, and dismantle the research point by point, such as solving the value of a single livestock hanging plow ten gold, solving the ten gold to adapt to the height adjustment of livestock, and solving the ten gold of the adjustment of the depth of the ploughshare into the soil. ”

Li Su believes that there will be brave men under the heavy reward, and although he himself does not know very well, he can help check the quality, and can also help them break down the total R&D goals into small goals that are easy to achieve. After the craftsmen have made the semi-finished products, Li Su can still help check the checks during the test to see if it is roughly similar to the farmhouses seen in later generations, or at least similar in function.

Sure enough, after listening to the appreciation, all the craftsmen were enthusiastic, the key is that everyone has the direction of struggle, and the demolition is so fine, many people pick one of them to specialize in pondering. Even if one group made it and the other two groups did not achieve results, Li Su was allowed to give a bounty of ten catties of gold for a small target alone.

The reason why many large projects in modern science and technology research and development are not promoted is that modern "scientific research management" has not kept up. If a project is too big, and the overall goal is not completed because of the pig teammates' delays, resulting in no one being able to pay bonuses, it will greatly negotiate the enthusiasm of the R&D personnel.

But Li Su is obviously self-taught and well-versed in human nature, so he avoids this problem.

So among the three points, the initial solution was "how to put a plow frame on a single elephant" this subdivision of the small goal, a carpenter quickly made a set of saddle-like things, directly on the elephant, and then an elephant can pull the plough alone - in fact, this is also very easy to think, because the four-horse carriage uses a wheel to set the horse, and a single horse does not have to use the saddle directly, it is nothing more than the saddle is changed to become an elephant set.

Li Su didn't say a word, on the day of the invention of this "set of elephant mechanism", he rewarded the group of craftsmen with ten catties of gold in public, and gave him ten hectares of fertile paddy fields in his fiefdom in Pixian County, and wrote the title deed on the spot with the seal of the Marquis of Pixiang.

The other two groups of craftsmen were so inspired that they worked hard to work overtime, and they actually developed the structures such as "Quyuan Plow" and "Three-Plough Plough" within half a month. Although it is not exactly the same as the Quyuan plough of the Tang Dynasty in later generations, it is definitely not bad in function - Li Su is not according to the history textbook, and he doesn't know what the Quyuan plough should be like, as long as he is easy to use, even if it is more modern and better.

In addition, after having three ploughshares and three rows of ploughshares at the same time, it is very simple to expand to five or even seven ploughshares, which is nothing more than a simple copy of the horizontal structure. Finally, after the run-in experiment, Li Su and Guoyuan finalized that they could create two sizes of five or seven shares, which were selected according to the strength and width of the elephant.

If it is a relatively thin adult elephant of 15,000 Han Jin and a little narrower, then plough the five elements, and if it is the strongest elephant of 20,000 Han Jin, then plough the seven elements, which is basically equivalent to the strength gap between elephants and cattle, and the elephant must be able to move.

After Guo Yuan found out that the plough was successful, he had an idea and happily suggested to Li Su: "Dudu, this thing can be described as an unexpected harvest, and we can also apply these techniques of 'single animal plough' and 'curved plough adjusting the depth of the plough into the soil' directly applied to today's ox plough."

If this is promoted to build tens of thousands, it is equivalent to making the cultivation power of the entire Shu land rise several percent out of thin air! Originally, one cow was only enough for spring plowing of five Zhengding and 500 acres of land. After replacing the new plough, it can provide at least eight Zhengding and 800 acres of arable land! Niu Li saves too much! This is much greater than the benefits of Nanzhong's side. ”

Li Su is also quite pleased: "It's a pity that this year's spring ploughing can't catch up, and there is not so much pig iron to make new plows in a hurry." Write this down first. Before we go back this year, we must take the smokeless peat from the Tushui basin in the north of Jianning County to go back to scorch and smelt pig iron, and after there is more steel, we can make new ploughshares after the autumn harvest, and we will use them for spring ploughing next year. ”

What Li Su mentioned in his mouth is obviously the large anthracite coal mine between Qujing in Yunnan and Liupanshui in Guizhou in later generations. Some of those coalfields are shallow and can be mined in the open pit. Those who are too far away from the Niulan River (Tushui) can't make a big move, so just dig up the superficial high-quality coal along the Niulan River.

In addition, there is actually a little bit of iron ore between Zhaotong and Qujing in Yunnan, but to be honest, the Han Dynasty has this kind of "hundreds of tons per year" steel production, and it is enough to squeeze some iron ore out between the teeth, until the Song Dynasty, the Han people have never lacked iron ore, and the iron ore that is easy to mine in Sichuan is enough, so there is no need to ask the way.

The amount of anthracite coal used is to go to the goal of "smelting 500 tons of iron per year", and no matter how extensive it is, it will waste one or two thousand tons of coal, and the same is "as long as you find any high-quality coal field, it will definitely be enough", and the bottleneck is definitely the scale of smelting furnaces and blacksmiths. Before, it was nothing more than that the coal in Sichuan was bituminous lignite, and the quality was not good.

……

For the great cause of farming and naturalization of the Southern Barbarians, Li Su can be said to have worked hard, and he didn't even go back to Chengdu for the New Year, so he spent the New Year in the beach swimming villa, and has been spending the Shangyuan Festival, occasionally mentioning the acceptance of the work.

The only good thing is that this winter is as warm as spring, and he thinks it is a "winter vacation to the southern seaside". Although he is not facing the real sea, but Dianchi Lake and Fuxian Lake.

After the Shangyuan Festival, the elephant plough and elephant mill (rollers used for road compaction) were finally fully matured, and the trade road from Kunming County to Zhudong County was also crushed into a relatively smooth loess road, which allowed oxen-drawn trucks to pass smoothly.

On the third day after the Shangyuan Festival, because the weather in Yunnan was warmer, Li Su asked Guoyuan to gather Meng Wei, Meng Xin brothers and others to visit the performance ceremony of "Elephant Plough Ploughing". At the same time, they have also urgently built thousands of iron ploughshares and one or two hundred sets of elephant ploughshares so that they can be promoted at any time.

Meng Wei was also stunned when he saw the Han craftsmen and the mahouts of his tribe working together to drive a 20,000-pound giant elephant pulling a curved plough with seven rows of ploughshares to plough the land efficiently.

"Li Dudu is really a celestial man, and our Meng clan will never dare to disagree from now on! The governor can actually drive the giant beast to cultivate the land and build roads, and the magic is no less than driving the cattle, which is really God's help! There are more than three or four hundred elephants in my Meng's counties, and dozens of elephants at the least, all of which add up to nearly seven hundred elephants, and if they can all be promoted, they will be no less than five or six thousand cows! ”

Meng Wei also said: "There are seven or eight hundred thousand people in Ailaoyi, and they live in more hot fields and more animals and elephants than we do. I estimate that the total number of the Wailao tribes is about 1,600, and if the Governor can teach them this method, and add the benefits of trade that could have been promised, I am afraid that the Wailaoyi will also be happy to be used by the general of the expedition to the west. ”