Which of the following does not determine the available humus resources in a country?

The factor that does not determine the available humus resources in a country is evolution. Evolution refers to the gradual process of change in living organisms over a long period of time, and it does not directly affect the availability of humus resources in a country. On the other hand, births, deaths, and emigration can have an impact on the available humus resources in a country. Humus is a dark organic matter that forms in soil when plant and animal matter decay. The amount of humus in the soil depends on the amount of organic matter that is added to the soil over time. Births, deaths, and emigration can all affect the amount of organic matter that is available to be added to the soil. For example, if there is a high population density and a lot of food waste is produced, this can increase the amount of organic matter available for composting and eventually adding to the soil.