6. what is a saturated soil? a. soil in which the maximum size of the "a" horizon has been reached b. soil in which the amount of water exceeds the pore space c. soil that is at maximum carrying capacity for plant life d. soil that does not need additional nitrogen e. soil in which all the soil horizons are present 7. why is clay influential to soil composition and fertility? 8. fill in the blanks: a soil () is a collective sequence of layers that are differentiated by physical, chemical, and biological characteristics. the () layer has a darker color due to the leaching of humus from the layer above.