Clue: Exploit plot in gathering stock, improving plant conditions? (14)
Answer: FEATHERBEDDING
Explanation: Definition: improving plant conditions?

**FEAT** ("exploit") + **BED** ("plot") *in* **HERDING** ("gathering stock")
 

 
*Featherbedding is the (now rare) practice of hiring more workers than is actually required (normally after negotiation with unions), so conditions in a plant or factory would improve, at least temporarily, for workers who may feel less pressure at first.