If you look up the definition of "organism", you will arrive at the conclusion that soil is NOT a living organism. It is host to numerous living organisms, which are important for its functioning.

A dead body is full of living organism, but you would not consider a dead body alive, would you?

Hi,

first of all, we need a common definition of "organism" . Based on the following definition, you will conclude that soil is an organism but no a living one stricto sensu.

1. An individual form of life, such as a plant, animal, bacterium, protist, or fungus; a body made up of organs, organelles, or other parts that work together to carry on the various processes of life.

2. A system regarded as analogous in its structure or functions to a living body: the social organism. source: http://www.thefreedictionary.com/organism

Looking to the definition of "living organism": An individual living thing that can react to stimuli, reproduce, grow, and maintain homeostasis. It can be a virus, bacterium, protist, fungus, plant or an animal. Source: http://www.biology-online.org/dictionary/Organism

Soil like a real living organism is able to react to stimuli (of course this take much larger timne scale than real living organism) and grow, but it cannot reproduce and realy maintian homeostasis.

Even if the soil is not "organism" in fact, it should be as much "living" as possible :).  Soil life is very important for plants and so for people as well :)

I like Muhammad Shaaban's simplified definition.

Pleas let me to introduce a Hungarian definiation:

The soil is a heterogeneous polidiperz system that can be characterized by physical, chemical and microbiological properties.

From a Geotechnical engineer's prospective, for decades soil has been considered to be made up of solids, water, air phases (3 Phases), theoretically neglecting any living organisms and considering no/little impact of their life cycle and associated processes on physical and chemical properties of soil. However, based on several experimental evidences living organisms in soil should be treated as an independent phase. To sum up, living organisms are a part of the soil system but fundamentally I think soil is not a living organism (a soil philosopher might think otherwise).