Broiler production in Alabama ranks third in the United States. In 1999, 972.2 million broilers were produced in Alabama, which generated $1.88 billion in revenue to the state.  Broiler production is also the number one agricultural enterprise in Alabama, accounting for approximately 55% of the total farm receipts.  Broiler production is a growing industry in the state with an average growth rate of 1.56% from 1990 to 1999.

Although it is regarded as the most valuable agricultural industry in the state, broiler production also is responsible for a huge amount of litter production, which can cause air and water quality problems.  The estimated amount of broiler litter production in Alabama is about 1.5 million tons each year. Broiler production in Alabama is clustered in relatively small, localized areas of the state, resulting in a high concentration of broiler operations in a few counties, particularly in North Alabama.  For example, the four major broiler production counties (Cullman, Blount, DeKalb, and Marshall) are located in North Alabama.

AAES researchers made this assessment by ranking North Alabama counties as “surplus” or “deficit” broiler litter counties based on the major crop acreage and the total estimated litter production in each county.  The objective was  to find the least expensive transportation routes for broiler litter transfer using a phosphorus consistent rule. The phosphorus consistent rule is defined as an application of broiler litter according to the phosphorus need of a crop.

Phosphorus remains a primary element of concern from the surface water quality point of view.  Phosphorus is generally considered a limiting nutrient for eutrophication in fresh water.  Broiler litter contains a high concentration of water soluble phosphorus (often more than 90 mg per pound) making it susceptible to runoff.  If applied excessively, it may cause water pollution problems.  Therefore, scientists focus on phosphorus management when developing economical solutions for broiler litter transportation.

Two uses for broiler litter include using litter for crop nutrients and as animal feed.  Because broiler litter is not widely accepted in the state as an animal feed,  its primary use is as a source of crop nutrient.

The average nutrient composition of broiler litter as 62:60:40 nitrogen:phosphorus:potassium (N:P₂O₅:K₂O) pounds per ton was used for this analysis. Current estimates show that the average nutrient value of broiler litter in Alabama is worth $35.60 per ton, but lack of a well operating market and imperfect information results in the sale of broiler litter for approximately $10 per ton.  Since all the nutrients from litter are not available to the crop at the same year, researchers assumed that only 50% of organic nitrogen is released during the first year, 12% in the second year, 5% in the third year, and 2% each in the fourth and the fifth years. It also was assumed that litter contains 0.9% organic nitrogen and 2.2% inorganic nitrogen. Additionally, researchers assumed that only 80% of inorganic N, 71% of organic N, 75% of phosphorus, and 75% of potassium were available.  The chemical fertilizer cost for these calculations was obtained from the Alabama Cooperative Extension System (ACES), which estimates that the custom applied prices of  N, P₂O_5, and K₂O are 0.30, 0.28, and 0.16 dollars per pound, respectively.  These prices also include the costs for hauling and application. 

For example, the ACES-recommended amount of fertilizer for corn and cotton for North Alabama is 60:40:40 and 120:40:40 (N:P₂O_5:K₂O) pounds per acre, respectively.  If chemical fertilizer is applied to meet this need, it will cost $35.60 and $53.60 per acre of corn and cotton, respectively. Given the assumption of the nutrient content in broiler litter and prevalent rates of loading (50 cents per ton), hauling (10 cents per ton per mile), spreading ($3.50 per acre), the use of broiler litter at the recommended rate of the P requirement provides a cost saving of $18.52 per acre compared to the use of chemical fertilizer (Table 1).  This indicates that litter can be transferred up to 163.74 miles from the production facilities. This analysis proves that litter can be economically transferred from concentrated litter production counties such as Blount, Cullman, DeKalb, and Marshall to the crop production counties such as Madison and Limestone. Table 2 shows the economical distance for the litter transportation in two major crops in the region based on the assumptions made here. It is evident that poultry litter can be profitably transferred from the area of production to the area of application.

After determining that it is economically feasible to transfer broiler litter, researchers mapped the most economical transportation routes from the surplus counties to the deficit counties. Surplus counties are those counties where broiler litter produced is in excess of crop nutrients need in the county based on the phosphorus consistent application rate. The deficit counties are those counties in which litter produced is less than the nutrient needs of the crops grown in the county. 

Four crops selected for the analysis are corn, cotton, wheat, and hay. Crops such as soybeans and peanuts were not selected because when nutrients are applied to these crops based on the phosphorus need, nitrogen will be over applied. Based on these assumptions, calculations show that among 29 counties in North Alabama, 13 counties are deficit counties and 16 counties are surplus counties.  The amounts of deficit and surplus litter in each county based on the nutrient requirements for four crops are shown in Table 3.  Among 16 surplus counties, Cullman, DeKalb, Blount, and Marshall alone constitute 65% of the surplus litter.

Four major crops grown in 29 counties require 40,586 tons of N, 18,205 tons of P₂O₅,  and 18,205 tons of K₂O to meet the nutrient requirements. The purchase of this amount of crop nutrients in the form of commercial fertilizer would cost $40.3 million.  A total savings of $17 million is possible by using broiler litter as a substitute for chemical fertilizer in North Alabama. The result from the transportation model reveals that 66% of broiler litter can be utilized within the region leaving 33% of broiler litter as a surplus.  Fifty-five percent of total litter utilized is used within the counties and 45% of the litter is transferred across county lines. If removing the litter from the Blount, Cullman, DeKalb, and Marshall counties is considered a priority, it could be done at a reduction in the highest possible fertilizer/transportation cost savings of $500,000 compared to the nonpriority model.

The results of this study reveal that the surplus litter production problem in North Alabama cannot be solved by transferring litter within the 29 northernmost counties. However, the problem can be solved in four major broiler-producing counties with only $500,000 in reduced cost savings compared to the litter transportation model where emphasis was put on the transportation of litter at the cheaper cost irrespective of which surplus counties the litter originated from.

The study also reveals that it may be possible to solve the litter problem if litter is transported out of the North Alabama counties to other counties in Alabama based on the phosphorus consistent rule.Of course, this requires the acceptance of litter by crop producers and assistance by the government to make it an acceptable alternative to chemical fertilizers. Also, once the phosphorus indexing currently being developed by the Natural Resources Conservation Service is disclosed, it is likely that the allocation decision presented here may change. However, this study illustrates that litter can be transported to other areas to minimize the environmental problems in the region.  This study did not consider the benefit of organic matter development that may be realized if poultry litter is used for several years.

Adhikari is Graduate Research Assistant, Paudel is formerVisiting Assistant Professor at Auburn and Assistant Professor of Agricultural Economics and AgriBusiness at Louisiana State University, and Martin is Professor Emeritus of Agricultural Economics and Rural Sociology

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