Here, for your teaching pleasure, is a long quote on the value of corn (maize) in China. I often mention in class that New World crops were economically valuable, but I usually do not have much for details. Here is a long description of the Ten Conveniences and Five Profits of maize, taken from a memorial written to the Qianlong emperor in 1762 by a district magistrate named Wang Chongli. Wang seems to be pretty knowledgeable about the economics of peasant life.
Many grains are constrained by the season when it comes to planting and cultivation. Maize can be sown from February to April. There is no need to rush planting and rush harvest, this helps with utilizing agricultural labor. This alas is its first convenience.
When it sprouts , it grows into rough leaves and tall branches. they are not disrupted and impacted by wild grasses, weeding hence can be done later (not rushed) this is its second convenience.
It can be sown closer or far apart, the taller varieties even more so. It is very east to weed and tend, as they are not closely clustered. This is its third convenience.
When it blossoms, it grows a fluffy tail; strong wind and heavy rain don’t damage it. This is its fourth convenience.
It ripens but doesn’t turn yellow, drop to the ground and ruin itself. It can wait until you have harvested and stored other grains. This is its fifth convenience.
Its grains are firmly engrained to its kernel such that it would not fall unless you peel it; This makes it easy to pick and harvest. This is its sixth convenience.
Once it is picked, one can leave it anywhere, hence no need for pots and containers. This is its seventh convenience.
With other grains we need to separate the grain from its shell. Maize does not need this process of shelling. This is its eighth convenience.
We can pound it, grind it, turn it into grain or powder or make noodles; we can cook it whole, boil it and eat it any way we prefer. This is its ninth convenience.
We can tuck it under the sleeves (Chinese sleeves were often long and wide and could serve as wallets or bags) and take it on the road; we can eat it when it’s cold. This is its tenth convenience.
It grows deep and into four to five branches, each branch yields hundreds of grains, and this is far more than any other grain species. This is its first profit.
The red ones are hardy and the white ones are stickier, similar to other grains: this means it can be used as rice, it can be used to make wine or steamed buns, and they are filling. This is its second profit.
Its grains do not have skins; this makes its powder purer and softer than other grains. each dou (Chinese unit of dry measure for grain = 1 decaliter) can turn into 8 0r 9 sheng, the leftover can turn into 1 or 2 sheng to feed the animals which grow fatter on this. This is its third profit.
It can be eaten alone; it is even better when mixed with others like rice and wheat. This is its fourth profit.
Its brushed and branches can be used as fuel and they last longer than other do; they can be used as cushion materials for building and roofing. This is its fifth profit.
This quote is from Zheng Yangwen China on the Sea: How the Maritime World Shaped Modern China. Brill, 2011. pp.123-4. Zheng points out that this opinion is “virtually the same” as that published by a Spanish doctor in Mexico, published in 1591.