Stinky manure has resulted in a dozen complaints to Hawke's Bay Regional Council from Havelock North residents.
The odour was tracked to a paddock west of Te Aute Rd.
Environmental officer Ian Lilburn said a mix of wool dust and compost was spread on Tuesday and Wednesday mornings as a fertiliser/soil conditioner and dug in on Wednesday afternoon.
"Normally this product is okay but in this case the wool dust/compost mix was wet from recent rain, which really brings the odour out of the wool dust when it is disturbed in the spreading process," Mr Lilburn said.
"Generally there is little or no odour with just mature compost, or if this mix is dry and disked or hoed in straight away."