Steamed buns were the main food for usas a meal we frequently ate.

Even if we made steamed buns in ordinary days, we diwouldn'’t lastand using a little bit of wheat flour, we only used sweet potato flour and sorghum flour because we only had ahad very little wheat flour.

We also couldn't even stand using wheat flour. (???)

I don’t understand what you’re trying to say here

People in my village jointly owned the farmland of my village and worked (it) together, so no one really worked hard and the yield was very low.

Your original is fine, but you could say you “worked it together,” with “it” referring to the land. To “work land” or “work the land” is to labor on it to raise crops.

The staple foods for us were sweet potatoes, sorghum, soybeans and wheat.

Staple foods, or staples, are your main sources of nutrients.

We could only eat wheat flour steamed buns when our relatives visited us or [it was | during] some ceremonious holiday days, for instance, the traditional Chinese new year.

Even if we made steamed buns ion ordinary days, we didn't stand usinguse even a little bit of wheat flour, we only used sweet potato flour and sorghum flour because we only had a little wheat flour.

“Stand” doesn’t seem right in this context. Maybe you couldn’t afford to use wheat flour (because there wasn’t enough) or you couldn’t bear to use it (because it was too precious).

When we made noodles, we used large portions of sweet potato flour and small portions of soybean flour.

“Portions” isn’t wrong, but I think “amounts” would sound more natural, or “we used mostly sweet potato flour and a little bit of soybean flour.”

We also couldn't even stand using wheat flour.

I’m not sure what emotion or circumstances you’re trying to express with “stand.”

CWe cut sweet potatoes into chunks and boiled them.

Our dinner was usually steamed buns that were made of sweet potato flour and porridge that was made of water and sweet potato flour, too.

Our vegetables were sufficient, I think, because each family had a garden plot to grow[(in which) to grow | for growing] vegetables.

From the description (of the food we ate) in this article, you [would | will] know that we survived on sweet potatoes, aso did (most? many?) other people in my region.

Without “most” or “many,” we don’t know how common this was—it could have been just a few other people.

I still remember a [saying spoken by local people, "s | local saying]: "Sweet potato flour, sweet potato flour steamed buns, we can't survive without sweet potatoes."

TheOur food for us werewas sweet potatoes, sorghum, soybeans and wheat.

Steamed buns were the main food for usfood we ate most.

We could only eat wheat flour steamed buns when our relatives visited us or it was some ceremonious holiday days, for instance, the traditional Chinese new year, for instance.

Even if we made steamed buns ion ordinary days, we dicouldn't stand usingeven use a little bit of wheat flour, w. We only used sweet potato flour and sorghum flour because we only had a little wheat flour.

We also couldn't even stand usinguse wheat flour.

CWe'd cut sweet potatoes into chunks and boiled them.

From the food we ate in this article, you would know that we survived on sweet potatoes, and so did other people in my region.

I still remember a saying spoken by the local people, "sweet potato flour, sweet potato flour steamed buns, we can't survive without sweet potatoes."