Manipulate Pen Surface Moisture

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The pen surface moisture level has impacts on dust, odor, and ammonia volatilization. To high and odor and ammonia volatilization are increased, too low and dust is a problem. Finding an equilibrium where all three compounds are minimized is the goal to surface moisture application.

The Problem
Background
Experimental Methods
Results and Cost Analysis
The Solution

The Problem

Two of the biggest, and most obvious, challenges for feedlots are dust and odor. Unfortunately, the control of one is usually at the expense of the other. For instance to decrease dust emissions, the most common recommendation is to apply water to the pen surface. In doing so you increase the microbial activity in the surface crust and increase odor emissions. However, there are recommendations for the optimal surface moisture level to minimize both dust and odor emissions of 28% (37). The application of water to pen surfaces not only effects odor and dust, but also ammonia emissions. An increase in surface moisture can either bind ammonia in is ionic form (ammonium), or encourage disassociation of bound ammonium into ammonia, thus increasing the surface ammonia emissions. We wanted to see at what levels of moisture application ammonia volatilization was most effected.

Background

To achieve optimal dust reduction, without increasing odor or ammonia production, a surface moisture level of 28% has been recommended (37). A variety of methods have been suggested to achieve this moisture level including sprinkling, increasing stocking density (38), and increasing manure pack depth to increase surface moisture. Each of these methods has its benefits and drawbacks. In the Eastern Plains of Colorado where water is scarce and evaporation rate high, application of water to the pen surface is not practical. Instead, proper pen management and design is the best management tool of choice. However, water application is still practiced by a large fraction of producers. The problem here is that application of moisture to the corral surface might increase hydrolysis of nitrogenous compounds on the pen surface to form ammonia (9). This is because ammonia is highly soluble in water and accumulates in wet areas of the corral. When the surface begins to dry, and the water evaporates, approximately 12 % of ammonia volatilizes from manure due to its high oxidation potential and conversion of organic-N to ammonia-N (15).

Experimental Methods

Method. Coming Fall 2008......

Results and Cost Analysis

Results. Coming Fall 2008......

Cost Analysis. Coming Fall 2008.....

The Solution