1) The study evaluated the effects of two common equine stall bedding materials (pelletized straw and wood shavings) on the physical and chemical properties of composted equine stall waste. 2) Composting resulted in significant reductions in mass, organic carbon, and C:N ratio for both materials. Higher temperatures were maintained for longer with pelletized straw. 3) Differences were observed between materials for various parameters like available phosphorus, nitrogen content, and particle size distribution following composting. 4) Composting horse stall waste is a promising manure management strategy for small farms by reducing volume while providing nutrients, though bedding type can impact compost quality

1. EQUINE BEDDING MATERIALS EFFECT ON PHYSICAL AND
CHEMICAL PROPERTIES OF COMPOSTED STALL WASTE 1,Williams, 2 3 4 5 6
Komar*, S.J. C. , Westendorf, M. , Miskewitz, R. Mickel, R.C. ,Bamka, W.J.
1Extension Agent, Rutgers Cooperative Extension, Sussex County, Newton, New Jersey 07860, 2. Extension Specialist, Rutgers NJAES Cooperative Extension, New
Brunswick, New Jersey 08901, 3.Extension Specialist, Rutgers NJAES Cooperative Extension, New Brunswick, New Jersey 08901, 4.Assistant Research Professor,
Rutgers University, New Brunswick, New Jersey 08901, 5 Extension Agent, Rutgers Cooperative Extension, Hunterdon County, Flemington, New Jersey 08822, 6
Extension Agent, Rutgers Cooperative Extension, Burlington County, Westampton, New Jersey 08060
ABSTRACT RESULTS AND DISCUSSION
In recent years new bedding materials have been marketed to the All materials reached maximum temperatures during the first weeks of
composting. Among materials, only the pelletized straw maintained
equine industry. Limited research has been conducted to evaluate
temperatures above 55°C . This is in compliance with USEPA guidelines for
how composting impacts the physical and chemical properties of microbial decline of at least 15 days at 55°C. Temperatures were below this
these materials. In 2010, a study was conducted to evaluate the threshold for the remainder of the experiment (Figure 1) reaching
effects that bedding materials have on the physical and chemical temperatures near ambient by the conclusion of the trial. Composting resulted
properties of composted equine stall waste. Two bedding materials in significant mass reductions for both bedding materials with numerical
were evaluated including a pelletized straw product and wood differences observed between the straw and wood materials ( Figure 2.).
PhysicalWood Pelletized Straw
appearance of bedding materials after 100 days of composting. Organic carbon was reduced during composting for both materials suggesting
shavings. Differences were observed in final mass, organic matter, Shavings
that composting occurred for both treatments (Figure 3.). Differences were
particle size distribution and several chemical parameters.
observed in available P with concentrations increasing for both materials
Composting resulted in significant reductions in final C:N ratio for all MATERIALS AND METHODS (Figure 4.). No differences were observed in K concentration following
bedding materials with the greatest reductions occurring in the A study was conducted at the Rutgers Equine Science Center in New
composting (Figure 5.). TKN was greater in the pelletized straw material
straw-based material. Bedding materials appear to influence the Brunswick, New Jersey to evaluate the chemical and physical characteristics
following composting (Table 1.). Differences were observed in nitrate-N
of two common equine stall bedding materials following an aerated
physical and chemical properties of composted equine stall waste following composting with the greatest increase occurring in the pelletized
composting process. The bedding materials included a pelletized wheat
and can have dramatic impacts on the potential of using composted straw. Particle size was reduced for both materials following composting
straw product and pine wood shavings. Compost piles were constructed on
equine stall waste as a soil amendment. suggesting that organic C was degraded during composting (Table 2.)
May 12, 2010. Four replications of each of the bedding materials were
constructed and placed in a randomized complete block design for statistical
55
analysis. Digital thermocouples were used to monitor the temperature in the
50
center of each pile during composting. Physical and chemical properties of
Pile Temperature (degrees C)
45
the compost were evaluated using conventional laboratory procedures at the
40
beginning (day 1) and end of the composting process (day 100). Data were
35
subjected to analysis of variance and means separated using Fisher’s LSD 30
(P=.05). 25
_____ Wood
Shavings
20
Dry Mass Organic Carbon
400 100
80 Figure 1. Temperature (°C) during 2010 composting cycle.
300
%
Mass (Kg)
Stall waste is often spread on pasture or hay land Manure management will continue to be an important 60
making composting a potential solution for disposal. consideration for equine operations in New Jersey 200
40 Effect of Composting on Nitrogen
100 Initial Final 20 Initial Final
Nitrate Ammonium
TKN
0 0 Nitrogen Nitrogen
Treatment %
Pelletized Straw Wood Shavings Pelletized Straw Wood Shavings ppm ppm
INTRODUCTION Figure 2. Dry matter mass (Kg). Any column with an * is Figure 3. Percent organic Carbon. Any column with an * is
Initial Final Initial Final Initial Final
A typical 455 kg (1,000 pound) horse produces 0.023 m3 (0.82 ft3) of manure significantly different according to Fischer’s LSD (P=.05) significantly different according to Fischer’s LSD (P=.05) Pelletized 1.76 2.34 a 9.45 321.94 a 6.07 3.45
Straw
per day weighing more than 22.7 kg (50 pounds). In addition to manure, Wood Shavings 1.3 1.39 b 9.5 7.67b 6.09 6.01
equine stall waste includes various bedding materials such as straw or wood
Available P Available K
shavings. The amount of bedding added varies based on individual Table 1. Bedding materials effect on various forms of nitrogen. Any two
management, but has been found to range from 2.7 kg per day for wood 150 100
means in a column with a different letter are different according to Ficher’s
LSD (P=.05)
shavings to more than 3 kg per day for straw (Komar, 2009). Disposal of this 80
PPM
PPM
100
waste material can be an issue, particularly on small farms with limited 60
available acres for spreading manure. Recently, composting of this waste 50
40
Initial Final Initial Final
material has been suggested as a potential handling technique for small 20
CONCLUSIONS
equine operations. Much of the research comparing bedding materials’ 0
Pelletized Straw Wood Shavings
0
Pelletized Straw Wood Shavings
As the equine industry continues to expand in New Jersey, manure
impact on compost quality has been conducted using beef and dairy waste. Figure 4. Available Phosphorus (PPM). Any column with an * Figure 5. Available Potassium (PPM). Any column with an management will continue to be an important component of a well-managed
* is significantly different according to Fischer’s LSD
Limited research has been conducted to evaluate the impact that bedding is significantly different according to Fischer’s LSD (P=.05)
(P=.05)
equine operation. Farms with limited acres will need to maximize the
materials have on the chemical and physical characteristics of composted effectiveness of their manure applications to ensure maximum crop yield
equine stall waste. Particle Size Distribution while minimizing the potential for environmental impact. Composting horse
>1/4”
stall waste appears to be a promising manure management strategy by
> 1” >1/2” >1/4”
Treatment reducing manure volume while providing crop nutrients. Bedding type
Initial Final Initial Final Initial Final Initial Final appears to impact volume, as well as, the physical and chemical
Pelletized
Straw 25 22 26 24 25 26 24 28
characteristics of composted equine stall waste. More research is needed to
Wood
quantify the effectiveness of alternative bedding materials and to determine
Shavings 26 22 27 28 25 20 24 26 their acceptance by the equine consumer.
Table 2. Percentage of material particle size before and after composting.
Any two means in a column with a different letter are different according to
Ficher’s LSD (P=.05)