In addition to lacking space, China has a serious shortage of wood.  Even a hundred years ago, King noted that trees were scarce and small, and even those trees were heavily utilized by cutting the lower limbs for firewood.

As a result of the wood shortage, most buildings were traditionally made out of straw and clay.  Although the straw and clay tended to need frequent replenishing, the old building materials were perfect for throwing in the compost pit. 

Farmers were also very good at utilizing other types of plants for fuel.  Woody vegetable stems (especially rice straw) were frequently burned.  Although I approve of making full use of the resources at hand, King's description of the cooking fire requiring one person to constantly feed it small bits of straw sounds like a bit too much work.

Otherwise, King made the Chinese traditional agriculture system look so rosy that I find it hard to remember that, a century later, farming looks a lot different.  If you're interested in what's happened in the last hundred years, you should check out the overview on Wikipedia.