The quality or state of being fertile
The quality of being efficient
Measures are being taken by the zemstvos to increase the very low productivity of the forests.
We still have a thousandfold increase in productivity before us.
Liber was originally an old Italian god of the productivity of nature, especially of the vine.
And if your productivity fell, then your salary would fall as well.
If you have almost no productivity, amplifying it won't really help all that much.