Krishna P. Paudel and Keshav Bhattarai

Poultry production is the largest animal industry in Louisiana. It generated approximately $883.5 million in combined farm revenue of $450.8 million and value-added products at $432.7 million and employed more than 4,000 people in 2009. Among many types of poultry operations, broiler production generates the lion’s share of revenue and employment in the state. This revenue, however, also translates into a large amount of broiler litter (manure) as a byproduct.

Broiler litter is both a valuable resource and unavoidable byproduct that must be disposed of because of environmental concerns. Broiler litter contains 13 essential plant nutrients, but farmers apply broiler litter to their land based mainly on nitrogen, phosphorus and potash content. Because broiler litter has primary nutrients that plants need, it has a market value. When broiler litter is over-applied or applied for a long time without considering the nutrient needs of the crop grown, the nutrients, such as phosphorus, build up in soil. During rainy weather, phosphorus leaches into shallow groundwater or runs off into nearby water bodies, causing the problem of an increase in dissolved phosphates and the depletion of dissolved oxygen.

One alternative to alleviate this problem is to apply litter to fields farther away from where it’s produced. Louisiana’s commercial broiler production occurs mainly in the northern and central parishes (Figures 1 and 2). View a table of these parishes, the number of broiler farms, the amount of meat produced, potential hay and row crops areas where litter can be applied and the classification of each parish as surplus and deficit.

The first step to assess the potential use of litter as crop nutrients is to identify the parishes with surpluses and deficits. Surplus parishes are those where litter production is more than can be used as crop nutrients, and deficit parishes are those to which litter can be transported from the surplus parishes and applied to cropland. In theory, litter transportation from surplus parishes to deficit parishes can occur as long as it is economical to do so. This study first identifies the surplus and deficit parishes and then calculates the breakeven distance to which broiler litter can be transferred from the production facilities to crop production areas.

Breakeven distance is the distance from litter production sites to areas where the costs of applying litter or commercial fertilizer are equal. This distance is based on the cost of chemical fertilizer, the costs of loading, transporting and spreading litter and the amount of fertilizer generally recommended for a crop in a given area. In an LSU AgCenter survey, Louisiana broiler producers reported some of these costs as shown in Table 1.

The major row crops grown in these broiler-producing parishes are corn, cotton, sorghum and wheat. Additionally, broiler litter can be applied on Bermuda grass hay.

The nutrients available in litter can vary, based on the bedding material, weather conditions and broiler feed. The average nutrient content in a ton of broiler litter is 62 pounds of nitrogen, 60 pounds of phosphate and 40 pounds of potash. Based on a fertilizer market price of 53 cents per pound for nitrogen, 88 cents per pound for phosphate and 77 cents per pound for potash, one ton of litter could be worth about $116. Based on nutrient recommendation, breakeven distances for each crop and hay are calculated and shown in Table 2.

Broiler litter application rates used in this study follow a phosphorus-consistent rule, which means litter application is based on the phosphorus needs of plants. Breakeven distances were calculated using a transportation cost of $3.88 per ton per mile based on the survey of Louisiana broiler producers and a cost of 48 cents per ton per mile based on the rate the State of Louisiana uses to reimburse employees. Other costs are the same as obtained from the survey. Transportation costs as low as10 cents per ton per mile have been used in other broiler litter transportation studies done elsewhere.

Based on a cost of $3.88 per ton per mile, the breakeven distances are 26 miles for corn, 22 miles for cotton, 25 miles for sorghum and 26 miles for wheat and hay. If a transportation cost of 48 cents per ton per mile is used, the breakeven distances are 211 miles for corn, 177 miles for cotton, 203 miles for sorghum, 208 miles for wheat and 209 miles for hay. If breakeven distances are calculated based on the costs reported in the survey, litter could not be hauled far from the parish border.

The green area in Figure 2 indicates where litter can be applied in crop production. Sufficient suitable land parcels needed for proper litter disposal are much farther than the 22-mile breakeven distance from the broiler production facilities. Because only three parishes – Natchitoches, Vernon and Winn – out of 11 broiler-producing parishes show deficits, excess litter production and its safe disposal will continue to persist as a problem without some form of support provided to farmers to transport broiler litter.

If the transportation cost is relatively inexpensive – for example, 48 cents per ton per mile – however, litter can be transported from surplus-litter-producing parishes to many northern and central Louisiana parishes. If all other components of a litter-to-fertilizer market function, this could solve the excess-litter disposal problem in the state.
 
Krishna P. Paudel, Associate Professor, Department of Agricultural Economics & Agribusiness, LSU AgCenter, Baton Rouge, La.; Keshav Bhattarai, Professor, Department of Geography, University of Central Missouri, Warrensburg, Mo.

(This article was published in the spring 2010 issue of Louisiana Agriculture.)