Value of Poultry Litter in South Georgia25 August 2014
The University of Georgia's Claudia S. Dunkley and Dan L. Cunningham (both Extension Poultry Scientists at the Department of Poultry Science) and Glendon H. Harris (Extension Soil Scientist at the Department of Crop and Soil Sciences) reveal the results of survey conducted to assess the value and utilisation of poultry litter among south Georgia poultry and crop producers.
Poultry production is the number one agricultural business in the state of Georgia. The 2009 edition of Georgia Poultry Facts published by the National Agricultural Statistics Service revealed that the total farm value of poultry and eggs produced in the state increased by 8 per cent to $3.94 billion for the 2008 production year. With more than 5,000 poultry farms in the state, it is clear that a large volume of poultry litter is generated each year. Of the 10.2 million tons of poultry litter generated annually in the US, Georgia generates approximately 2 million tons.
Over the years, poultry litter has been used for composting, pelletizing, and converting to electricity, steam and biogas; however, the most common use has been land application. Crop producers use poultry litter to add humus and nutrients to the soil. Farmers who cultivate cotton, corn, pecan, forages, tobacco, sorghum, pine forests and a variety of fruit trees use poultry litter to improve their soil fertility. These producers may use poultry litter as either the sole fertilizer or in combination with traditional inorganic fertilizers.
Poultry litter is a mixture of bedding material, manure, spilled feed and water. The nutrient content varies with the type of bird produced (i.e., broiler, pullet or breeder) and the number of flocks grown on the litter, but generally approximates a 3-3-2-grade fertilizer, which equates to a total of 60 pounds of nitrogen, 78 pounds of phosphate and 56 pounds of potassium on a per-ton basis. Not all nutrients in poultry litter are available to plants. About 60 per cent of the nitrogen is available, 80- 100 per cent of the phosphate is available and 100 per cent of the potassium is available.
Poultry litter has an organic fertilizer value in excess of $80.00 per ton based on current fertilizer prices (Ritz and Merka, 2009). When Gascho et al. (2001) looked at poultry litter use in the Southern Coastal Plains based on the value of a harvested crop, a ton of stack-house broiler litter added $103.74 acre per year to the crop value. They also found that broiler litter application increased phosphorus, potassium, calcium, magnesium, zinc, manganese and copper concentrations in the surface soil. Armed with this information, a survey was conducted to assess the value and utilization of poultry litter among south Georgia poultry and crop producers.
The Survey Process
Litter utilization surveys were distributed at UGA Cooperative Extension meetings held for crop producers in 64 counties across South Georgia. A total of 23 questions were compiled and a total of 165 farmers responded. The questions were designed to target crop producers who were using or had used poultry litter as a source of nutrients. Not all respondents answered all questions because some did not utilize poultry litter.
The total acreage of land under cultivation varied widely among the farmers but averaged 1,000 acres, with the smallest farm being 4 acres and the largest being 6,000 acres. Because crop producers in South Georgia mainly use broiler litter, table egg layer manure use was omitted from the questionnaire.
Summary of Findings
Three major soil types are used for agricultural production in South Georgia: coastal plain, deep sand and piedmont. The type of soil on each farm was of interest because poultry litter is an excellent source of humus, which binds soil particles together and improves soil’s water holding capacity. The results from the questionnaire showed that 65.92 per cent of respondents farmed on coastal plain soil, 25.70 per cent farmed on deep sand soil and 8.38 per cent farmed on piedmont soil (Fig. 1). Some respondents had more than one soil type on their farm. The use of inorganic and organic fertilizer did not differ by soil type.
Type of Crops Grown
The types of crop farmers grew were important because of the specific nutrients each would obtain from the poultry litter. The survey results (Fig. 2) showed that 75.49 per cent of respondents grew tree and row crops (specifically pecans, peanuts, cotton and corn). A total of 18.14 per cent of respondents grew tobacco and forages such as sorghum and rye grass. Vegetables were grown by 6.37 per cent of respondents. The results were not divided into specific crop types.
Use of Poultry Litter and Inorganic Fertilizer
Of the 165 respondents, 50.30 per cent utilized poultry litter as a source of nutrients in their production while 49.70 per cent did not use poultry litter (Fig. 3). Of the total number of growers who used poultry litter, 40 per cent had been using it for less than three years, 26.25 per cent had used it for four to six years and the remaining 33.75 per cent had used it for more than six years (Fig. 4).
When asked if inorganic fertilizer was used as a source of nutrients, 77.54 per cent of respondents said yes while 22.46 per cent said no (Fig. 5).
A total of 75.64 per cent of the growers who used poultry litter also used inorganic fertilizer while 24.26 per cent of crop producers used poultry litter as their only source of nutrients (Fig. 6).
When asked whether they used a combination of poultry litter and inorganic fertilizer, 34.48 per cent of respondents said they used both at the same time while 65.52 per cent indicated they did not.
Source of Litter
Poultry manure can come from the variety of sources such as layer houses, broiler houses, breeder houses and pullet houses. The survey results showed that more than 38 per cent of the growers used litter from broiler houses; only 6 per cent used litter from breeder houses (Fig. 7). A total of 6 per cent of growers utilized litter from both broiler and breeder houses. Less than 2 per cent of producers were unsure about the litter source.
Composting poultry litter can be beneficial because the heat generated during the composting process can reduce the bacterial load. The survey results showed that 65.52 per cent of growers removed litter directly from the poultry houses and placed it onto their fields while fewer than 35 per cent indicated that their litter was composted before application (Fig. 8).
A wide variety of materials can be used as bedding in poultry houses. The material that is selected often depends on availability and cost. In South Georgia, sawdust, wood shavings and peanut hulls are the most common bedding materials. Rice hulls, paper pulps and sand can also be used but none of the respondents in this survey utilized them. When asked what material was used in the bedding, 39 per cent of respondents used wood shavings, 35 per cent used peanut hulls, 23 per cent used sawdust and 3 per cent did not know.
The survey also compared the frequency of litter and inorganic fertilizer applications. The data showed that 41.72 per cent of respondents applied litter once per year compared to 45.70 per cent of farmers who used inorganic fertilizer (Fig. 9). Only a small percentage of inorganic fertilizer users (0.66 per cent) and poultry litter users (1.32 per cent) applied treatment less than once per year. Compared to litter users (2.65 per cent), respondents who applied inorganic fertilizer (7.95 per cent) did so more than once per year.
The amount of fertilizer and poultry litter farmers apply to their land each year and the amount of money paid for these amendments is an indicator of the amount of money involved in fertilizing the soil. Since not all crop producers cultivate all of their land each year, respondents were asked to indicate the amount of litter and fertilizer they applied per acre. Of the farmers who used fertilizer, 33.69 per cent applied up to 250 pounds per acre (Fig. 10). Almost half (49.06 per cent) applied 251-500 pounds per acre, and 16.99 per cent applied more than 500 pounds per acre. The amount and type of fertilizer used depended on the type of crop planted.
Cost of Fertilizer Use
Farmers who used inorganic fertilizer paid a variety of prices depending on the type of fertilizer purchased, from up to $500 per ton (46.67 per cent) to $600-$1,000 per ton (46.67 per cent) to more than $1,000 per ton (6.67 per cent) (Fig. 11). Responses indicated that 14.29 per cent of growers used nitrogen fertilizer, 1.79 per cent used potash and the remaining 83.93 per cent applied mixed fertilizer. None of the respondents applied phosphate fertilizers.
The amount of litter applied to the soil depended on the crop, with more litter applied to land on which cotton or other row crops were grown. Figure 12 shows that the majority of crop producers (92.86 per cent) applied more than 1 ton of poultry litter per acre, while only 7.14 per cent applied 1 ton per acre.
Cost of Poultry Litter
Respondents were asked how much they paid for litter, and the cost ranged from $10 to $55 per ton. The results showed that 27.42 per cent of growers bought litter for $10-20 per ton while 43.55 per cent purchased litter for $21-35 per ton. Just over 29 per cent bought litter for more than $35 per ton (Fig. 13). The wide variation in prices paid for poultry litter could be the result of differences in availability, transportation and handling costs as well as lack of information on poultry litter’s value. It is also important to note that although a question addressing this issue was not included in the survey, some of these crop producers also owned poultry or received poultry litter from family members who were poultry producers.
Acreage Under Cultivation
Crop growers in South Georgia usually cultivate large acreages. The following results place the respondents into five groups based on the amount of land on which they applied inorganic or organic (litter) fertilizer. Figure 14 shows that 25.83 per cent of respondents applied some form of soil amendment to up to 250 acres, 22.5 per cent fertilized 251-500 acres, 10 per cent fertilized 501-700 acres and 10 per cent fertilized 701-1,000 acres; 31.67 per cent fertilized more than 1,000 acres with inorganic fertilizer, poultry litter or both.
Crop Yield Using Poultry Litter
Producers use soil test results to decide on the type of fertilizer they will apply to their land. The results from this survey showed that 100 per cent of producers who utilized inorganic fertilizers tested the soil prior application. In contrast, 89.23 per cent of producers who used poultry litter tested their soil prior to application while 10.77 per cent of litter users did not test their soil before they applied litter.
Inorganic fertilizers usually clearly label their nutrient content or ratio of ingredients. The same is not true for poultry litter and other organic fertilizer sources. The nutrient content of poultry litter can be obtained by sending a litter sample to a lab. When asked if the litter was analyzed prior to use, 74.58 per cent of respondents said yes while 25.42 per cent said no.
There are numerous reasons why crop producers utilize poultry litter, including according to the survey crop yield. When asked to compare the yields of crops fertilized using poultry litter to those using inorganic fertilizers, 49.15 per cent of respondents indicated that crop yield was equal regardless of the nutrient source; however, 45.76 per cent reported that poultry litter produced better yields than inorganic fertilizer and 5.08 per cent said it was less (Fig. 15). These reports were similar to those published by Gascho et al. (2001), who observed that litter application increased cotton, pearl millet, wheat and canola yields while reducing peanut yields.
While poultry litter has benefits as an organic fertilizer, it is not always readily available and some crop producers will have to travel great distances to obtain it. The results from this survey showed that 24.03 per cent of litter users travel up to 20 miles to get the litter while 41.09 per cent of inorganic fertilizer users travel the same distance to obtain inorganic fertilizer (Table 1). Only 6.98 per cent of litter users traveled 21-50 miles to obtain their fertilizer compared to 10.85 per cent inorganic fertilizer users. However, when the distance increased to 51- 100 miles, 4.65 per cent of litter users traveled this distance compared to only 0.78 per cent of inorganic fertilizer users. About 11 per cent of litter users traveled over 100 miles to obtain poultry litter compared to 0.78 per cent of inorganic fertilizer users who traveled that distance.
Table 1. Percent of growers who traveled various distances to obtain litter or inorganic fertilizer.
|Type of Fertilizer||Distance Traveled (in miles)|
Application of Litter
How the litter is spread and who spreads it can impact the final cost. A total of 44.93 per cent of respondents who used litter applied it pre-plant compared to 42 per cent who incorporated it and 13 per cent who strip-tilled it (Fig.16). More respondents spread the litter themselves (58.33 per cent) rather than have someone else spread it for them (41.67 per cent) (Fig. 17).
One unfavorable impact of litter application is that of neighbor relationships. There are often complaints about the odor, particulate matter and insects that can be associated with freshly spread litter. A total of 55.56 per cent of respondents said they received complaints from their neighbors while 44.44 per cent said they did not (Fig. 18).
- On average, poultry litter contains 60 pounds of nitrogen, 78 pounds of phosphorous, and 56 pounds of potassium, per ton.
- Poultry litter has a computed fertilizer value in excess of $80.00 per ton.
- Poultry litter has practical value to a variety of crop producers:
- 50 per cent of crop producers in South Georgia use poultry litter; 24 per cent use it as their only source of fertilizer.
- Most crop producers use poultry litter at a rate of 2 tons per acre.
- Crop producers spend a substantial amount of money on inorganic fertilizers each year, with more than half of these surveyed spending $600 to $1,000 per ton per year.
- Crop producers apply fertilizer to large acreages each year, the cost of which varies based on the type of fertilizer.
- With only about 50 per cent of producers using poultry litter, opportunities exist for more application. The lack of more widespread use could be a result of unavailability of litter or the lack of information on the value of poultry litter as a fertilizer.
- Approximately 45 per cent of respondents indicated that applying poultry litter improved yield.
- Crop producers utilizing litter indicated a willingness to travel great distances to obtain it.
- The percentages of complaints from neighbors indicate a need for use of best management practices for poultry litter application.
Gascho, G.J., Hubbard, R.K., Brenneman, T.B., Johnson, A.W., Sumner, D.R., and Harris, G.H. 2001. Effects of broiler litter in an irrigated, double-cropped, conservation-tilled rotation. Agron. J. 93:1315-1320.
NASS - National Agricultural Statistics Service. 2009. Georgia poultry facts 2009 edition. USDA, NASS, Georgia Field Office.
Ritz, C. W. and W. C. Merka. 2009. Maximizing Poultry Manure Use Through Nutrient Management Planning. University of Georgia Cooperative Extension Bulletin 1245.