1) Fecundity 2) Fertility 3) Fruitfulness 4) Richness 
• (n.) Prolificness.
Pro·lif'ic·a·cy noun Prolificness. [ R.]
Measure of reproductive efficiency expressed in number of lambs born per ewe lambing.
prolificacy Producing abundantly and sustaining growth.
fertility noun the property of producing abundantly and sustaining vigorous and luxuriant growth; `he praised the richness of the soil`; `weeds lovely in their rankness`