Azkee is worried about the crops. They're unnaturally large, and he's concerned that Denom might have done something to "improve" the fields which might ultimately prove detrimental to the Ciphers.
Character type completion breakdown
Science Boy - Use a Geiger counter on the container of special fertilizer and determine that it's got a moderate amount of radioactive residue in it.
Charisma Boy - If the player is skilled in both deception and persuasion/intimidation (Persuasion/Average, Deception/Average) he will be able to tell that Denom is withholding information about the situation and get a confession out of him.
Stealth Boy - Break into the storage shed by picking the lock (Lockpick/Average) or by stealing the key from Denom (Steal/Average). Discover the empty barrel of fertilizer with the glowing residue. If the player character knows the soil is radioactive, they can confront Denom with this evidence.
I discovered that the soil in the greenhouses has become radioactive somehow.
I found an empty barrel of contaminated fertilizer in a shed near the greenhouse.
I found out that Denom bought the contaminated fertilizer from a passing trader.
The man told him that it would make his crops grow fast and become large.
Bad dirt in food house.
I find funny dirt in can in shed.
Denom say he put funny dirt in food house. He make soil bad.