Manure Management

Four months ago I published my observations and impressions of a manure management practice that is becoming more common around here – namely liquid manure soil injection.  That post is a good primer and background for what was to come as I have learned much more about this injection process of nutrient management. 

One of the primary benefits is a reduction in odor.  Getting the manure off the soil surface and into the ground goes a long way in maintaining neighborly relations.  Liquid manure injection also reduces the loss of nitrogen as a consequence of volatilization. This means more of the nutrient being made available to the crop.  This reduces or eliminates the need for the purchase of commercial fertilizer.   

Injection – contrasted with splashing the manure over the surface and returning to till it in – also reduces the risk soil erosion and runoff (well contamination). This additionally makes it compatible with no-till planting preserving more of the soil organic matter. 

The injection equipment I observed being used consisted of tractor-mounted injector with a draghose system delivering the product.  Just like this... 

click on images for a closer look

Liquefied manure is supplied by a caravan of semi-tanker trucks.  Since you’re not driving the truck onto the field to inject the manure this reduces the risk of soil compaction and saves transportation costs attributable to labor and fuel. 

Last July I had an opportunity to watch the process in action - immediately across the road from where we live.  

It took about 30 minutes to stage and assemble the distribution equipment at the roadside. What followed was a parade of semi-tankers. 

After the initial queue of tankers was emptied of their odiferous contents they returned at regular intervals – only moments apart – to refresh the pump tank. 

These tankers are called nurse trucks and have roughly a 6800 gallon capacity.  They can discharge their load in about a minute. 

They were a constant presence throughout the day – so many that we lost count.

This technique of shallow manure injection has features and benefits well-suited to Door County's soils and karst geology. It also saves money.  It is a fascinating form of waste management to my eyes and a veritable ocean of cow shit to move. 

Who knew?