"He made a pit, and digged it, and is fallen into the ditch which he made."
– Psalm 7:15, King James' Bible
While fertile and rich as such, the soil of the New World will nevertheless not yield any fruit or treasure unless adequate payment in sweat and blood has first been rendered unto it. Labouring allows you to carry more dug out soil, and reduces the Phlegm cost of digging.
Allows you to carry 15 units of dirt instead of 10, and reduces the Pleghm cost for digging to almost 3/5 of what it used to be (Example: About 2.8 Pleghm per dirt before learning Labouring versus 1.7 Pleghm per dirt afterwards; both using a Wooden Shovel and +10 Soil Digging Artifact bonus).