James, no discussion on this topic is complete without the most
important component - energy.
'Vitality' is the ability of a lifeform, be it soil, plant or animal, to
survive, live, grow.
'Fertility' is the ability of a lifeform as defined above to reproduce
or sustain reproduction.
'Energy' is independent from vitality and fertility but enables both.
That is, a lifeform can have energy without having vitality or
fertility, but cannot have vitality or fertility without energy.
Roger
