Effects of Poultry Litter Use Rates on 
Coastal Bermudagrass Production and 
Water Quality in the Coastal Plain of North Louisiana 

 M. M. Eichhorn, Jr.
and
W. Allen Nipper
Hill Farm Research Station

1. Broiler litter is an excellent fertilizer source for bermudagrass hay production.
2. Louisiana's broiler industry generates more than 60,000 tons of broiler litter waste annually.

1. Portions of the Quachita and Red River Basins have been identified by the Louisiana Department of Environmental Quality as either partially or fully threatened by nonpoint sources of pollution.
2. Rainfall runoff and leachate from pastures were cited as likely sources of pollutants.
3. Poultry litter use has been suspected as a major source of pollutants.
4. "Best Management Practices" for broiler litter use on Louisiana's Coastal Plain bermundagrass hay pastures have not been fully developed.

A. Environmental  -- Evaluate surface applied stacked broiler litter (SBL) used for bermudagrass hay production on:

1.  runoff water quality
2.  ground water quality

B. Agronomic  -- Determine surface applied SBL used on:

1. bermudagrass yield, quality, nutrient content, and nutrient uptake
2. soil fertility status

The site:

A Coastal bermudagrass hay meadow on Bowie soil having a slope of 5.45 to 6.20% was used.  This hay meadow had been fertilized without any animal waste and managed for hay production for the last 20 years.
	Coastal bermudagrass is one of the predominant forages in North Louisiana for the production of hay and it is found on many poultry operations.
Demonstration plots:
	Ten demonstration plots of 96 ft x 200 ft provide two replications of five treatments for hay production.  Five plots are available for water quality sampling and are fitted with the equipment shown and described below.
Each plot is fitted with equipment at the base of the slope to a) measure rainfall, b) determine exiting runoff water flow rate, and c) collect and store exiting runoff water samples.
In addition, a lysimeter pan approximately 36 inches deep is used to measure leachate exiting the Bt soil horizon and to collect leachate water samples.

Treatments: Crop year April 1998 to April 1999

Following a 1 March application of 2 ton dolomitic agricultural limestone to amend soil acidity the following treatments were applied 16 April on demonstration plots.

1. Control [no commercial fertilizer or SBL applied].

2. Commercial Fertilizer Check-588 lb 17-5-25/A. [Applied again after the first hay harvest.]

3. SBL at 2 ton/A.

4. SBL at 4 ton/A.

5. SBL at 8 ton/A.

 Samples collected/plot and analyses:

• Exiting runoff waters: 30 water samples representative of 30 rainfall events greater than .5-inch; total and fecal coliform bacteria, TKN, NO₃-N, P, S, As, Se, B, K, Ca, Mg, Fe, Cu, Mn Zn, Cd, Pb, and Ni.

• Exiting groundwater from the Bt soil horizon: 13 samples following 13 rainfall events; same assay as #1.

• Commercial fertilizer: 2 samples collected prior to each application; same assay as #1 excluding bacteria assays and NO₃-N.

• SBL: 2 samples of each rate collected prior to application; same assay as #1 excluding bacteria assays and NO₃-N.

• Soil samples: 1 composite sample at 0-6-inch depth from 3 subplots, and 1 composite sample of A and B horizons collected prior to and after the cropping season; same assay as #1 excluding bacteria assays, TKN , and NO₃-N but including pH, Na, and Al.

• Plant samples: 3 samples collected/ harvest from 3 sub-plots of each demonstration plot ;

• same assay as #1 excluding bacteria assays, and NO₃-N but including Na, Al,and forage quality analyses crude protein, neutral detergent fiber, acid detergent fiber, and invitro true digestibility.

Crop management:

Demonstration plots were harvested when Coastal bermudagrass attained early-seedhead development. Persistent drought during the growing season limited the number of harvests to three; 1 June, 3 August and 21 September.
 

 Statistical analyses:

All data were subjected to statistical analyses using PROC GLM (SAS, 1990) and means separation with Fisher's protected least significant difference.
 

Significant Results:

Metal concentrations and use rate loads of SBL and commercial fertilizer were far below EPA 503 sludge rules.

Water quality of exiting runoff and ground waters were not impaired by use rates of stacked broiler litter or commercial fertilizer relative to concentrations of:

1. total and fecal coliform bacteria;

2. NO₃-N, S, As, Se, K, Ca, Mg, Cu, Zn , Cd, Pb or Ni.

SBL and commercial fertilizer enhanced forage quality.

Forage, crude protein, and digestible dry matter yield each maximized and optimized where stacked broiler litter was applied at 8 ton/A.

Use rates of stacked broiler litter enhanced the soil fertility status.

	Louisiana Department of Environmental Quality (DEQ)
	Similar Study in Cotton at Red River Research Station
	Bayou D'Arbonne Watershed Non-point Source Pollution Program

More information?

Contact:

M. M. Eichhorn, Jr.
Hill Farm Research Station
11959 Hwy 9
Homer, LA 71040
Office  (318) 927-2578
Fax  (318) 927-9505

meichhorn@agcenter.lsu.edu