Xiulote pondered carefully, at the same time recalling past knowledge. In this process, corn grew tall, providing stalks for the climbing soybeans. Beans wound around the maize, fixing nitrogen to replenish soil fertility. And pumpkins spread across the spaces between corn and beans, clearing the field of weeds.
The three crops formed a perfect symbiotic relationship, requiring little human management, which suited the situation in Central America, where only rudimentary stone tools were available.
Now it was late April; corn needed five months to mature and would be harvested around October, while beans planted later took about four months to mature, with a harvest around September. Early-maturing pumpkins only required a little over three months and would be harvested from August to September. Following the corn harvest at the beginning of October, they would decide whether to plant another round of beans at the end of the year, not for yield but to supplement soil fertility.
Nutritionally speaking, corn was the carbohydrate, beans the protein, and pumpkins played a role in satiating hunger, which altogether supported the daily survival of the common people. As for sunflowers, cocoa, and chili peppers, the village Elder indicated those were things the City-State folks enjoyed, which the village didn’t need.
Xiulote did some calculations: if you included the time consumed in widespread planting, it meant sowing in April, May, and June, with harvests in August, September, and October, making it difficult for the City-States to mobilize Militia from April to October, deterring them from engaging in warfare lightly. However, the Mexica City-State Alliance with ample Chinampas could mobilize a large force during this period to catch their enemies off guard and incidentally ruin their agricultural production.
Overall, the Milpa began with the slashing and burning of forests, followed by the successive planting of the Three Sisters—corn, beans, and pumpkins—and ended with fallowing the land for one to three years. The yield varied from one-fifth to one-seventh of that of Chinampas.
Xiulote made a conversion and figured that, depending on the variations in water and nutrients, each hectare of Milpa could sustain three to five people, that is, one person per three to five acres. This was slightly lower than the yield of the dry fields in the north of the Ming Dynasty at the time. Here, without the advanced agricultural technology of Huaxia, they simply relied on the high yield of corn and pumpkins. And in the barren mountains, the mountaineers would also grow sweet potatoes as supplementary food.
Watching the hardworking Otomi villagers in the fields and pondering the data just calculated, Xiulote suddenly realized that the total population of Central America might far exceed his expectations.
Even accounting for two years of fallow land, based on the supply of food, the density of most population centers in Central America would not be less than one-third that of the northern regions of the Celestial Empire at that time. And the Mexican Valley, blessed with countless Chinampas and no need for fallow periods, would have a population density close to that of Jiangnan in the Celestial Empire, which was Central America’s "Nanzhili."
Agriculture determined population, and population determined the potential of a nation. This is why the various nations of Mexico could so easily muster armies of over a hundred thousand for campaigns.
Across the Mexica region, from the northernmost Chichimec to the southernmost Zapotecs, from the westernmost Texcoco to the most eastern Nava, and the centrally located Mexica, this was a civilization believed by posterity to consist of at least fifteen million people, but Xiulote considered it to exceed twenty million — a civilization territory with the world’s highest yielding corn, pumpkins, sweet potatoes, and the increasingly spread potatoes.
Xiulote gazed across the distant fields, where golden hope shimmered. He looked at the seeds yet to sprout, which were the cradle of civilization.
"What does a Stone Age population of tens of millions mean?" Xiulote thought, and then he smiled.
"This will be another Celestial Empire, a Celestial Empire with tens of millions in its core population!"