Putting Nutrient Management to Work

Land application, especially field spreading, is in most cases the best use of poultry manure and litter. It recovers nutrients that would otherwise be lost, improves yield, and reduces the possibility of releasing this material to water and the environment.

Where land is available, manure/litter applications can be substituted for commercial fertilizers, reducing farmers’ costs and helping them comply with environmental laws. At the same time, land applications tend to use the largest amount of waste closest to the point of production.

To ensure that nutrients in waste are not overapplied to the land, the waste must be analyzed for the amount and type of nutrients it contains and the timing of applications must be adjusted to ensure that growing plants can use the nutrients. To accomplish this outcome, the litter should be uniformly applied at the recommended rate. The management practice that offers this assurance is nutrient management planning.

Nutrient management planning as a preliminary to land application has become a standard practice for recovering and using the nutrients in solid and liquid animal waste. It is, like composting, a centuries-old practice, which modern technology has substantially improved. Every poultry farm should have a nutrient management plan.

What Is a Nutrient Management Plan?

Nutrient management planning matches the nutrient needs of the plants and soil with the nutrient contents in the manure to achieve a proper nutrient balance. An effective nutrient management plan consists of the following core components:

• farm and field maps,
• realistic yield expectations for the crops to be grown,
• a summary of the nutrient resources available (the results of soil tests and nutrient analyses of manure, sludge, or compost),
• an evaluation of field limitations based on environmental hazards or concerns (e.g., sinkholes, land near surface water, highly erodible soils, steep slopes),
• application plans based on the limiting nutrient,
• plans that include proper timing and application methods (avoid application to frozen soil and during periods of leaching or runoff), and
• calibration of nutrient application equipment.

Experience will continue to refine this practice. For example, nutrient management is very often based on nitrogen as the limiting nutrient. Nitrogen is a challenging nutrient to manage; it is highly mobile, easily dissolving in runoff and leaching through soil. Phosphorus, on the other hand, is less mobile so it is less likely to move off-site. Buffer zones and filter strips are also planted at the edge of fields and around water resources — to protect them from both nitrogen and phosphorus.

Now, however, soil tests and soil performance are showing relatively high phosphorus levels even in areas that have not been traditionally high in phosphorus. In some cases, these levels are so high that phosphorus must now be used as the limiting nutrient; in other cases, the levels are so excessive that no phosphorus should be applied, perhaps for a very long time. And while buffer strips are helpful, they are not sufficient to reduce phosphorus to acceptable levels.

These conditions notwithstanding, phosphorus is an essential element in bird nutrition. Are we then facing a dilemma? If we go carefully into these new areas, probably not. The solution may be found in enzyme treatments or food additives. Many growers have shown that putting the enzyme phytase in the diet can help maintain bird health and reduce the amount of phosphorus in litter. Phosphorus reductions can also be achieved by treating litter and field soils with alum. As alum treatments also reduce ammonia volatilization, growers are once again provided with a key management notion: good waste management, bird nutrition, and maintaining good management practices year-round are interrelated.

The USDA Natural Resources Conservation Service and Cooperative State Research, Extension, and Education Service offices have prepared tables of the mean average amounts of key nutrients found in different kinds of manure (Table 1). These tables may be used to estimate the nutrient content of your waste source or stockpile. However, as this resource is produced and used under many different circumstances, it is always best to have samples of your supply tested periodically by a certified state or private lab.

Table 1

Type production unit	TKN	NH3N	P205	K20	Ca	Mg	S	Na	Cl	Fe	Mn	B	Zn	Cu
Meat type chicken, Broiler: Whole litter	71	12	69	47	43	8.8	12.0	13	13	1.2	0.79	0.057	0.71	0.53
Meat type chicken, Broiler: Manure Cake	46	12	53	36	34	7.0	9.2	10	–	1.2	0.69	0.044	0.60	0.41
Meat type chicken, Roaster: Whole litter	69	16	70	47	41	8.4	14	13	–	1.6	0.76	0.047	0.68	0.49
Meat type chicken, Cornish: Whole litter	59	12	57	59	41	22	–	–	–	–	1.1	–	0.92	0.61
Meat type chicken, Cornish: Manure Cake	62	17	39	39	30	14	–	–	–	–	0.67	–	0.50	0.46
Meat type chicken, Breeder: Whole litter	37	8.0	58	35	83	8.2	7.8	8.3	–	1.2	0.69	0.034	0.62	0.23
Commercial layers, Undercage/Alley Scraped	28	14	32	20	41	5.5	7.1	2.8	4.0	2.4	0.29	0.022	0.31	0.034
Commercial layers, Highrise/Deep Pit	34	12	51	26	76	5.7	4.8	3.4	6.0	2.8	0.44	0.036	0.35	0.058
Commercial layers, Liquid Manure Slurry	57	37	52	33	33	4.0	4.0	4.8	6.6	1.7	0.38	0.030	0.39	0.073
Commercial layers, Anerobic Lagoon Liquid	6.6	5.6	1.7	10.3	1.1	0.34	0.61	1.8	3.4	0.060	0.0069	0.0092	0.016	0.004
Commercial layers, Anerobic Lagoon Sludge	2.1	6.5	77	9.8	47	12.0	7.1	3.3	2.4	4.8	1.6	0.035	1.1	0.14
Turkeys, Poultry: Whole Litter	40	9.6	43	27	26	5.1	6.1	4.7	1.8	2.0	0.53	0.038	0.46	0.39
Turkeys, Grower: Whole Litter	55	12	63	40	38	7.4	8.5	7.6	12	1.4	0.80	0.052	0.66	0.60
Turkeys, Grower: Manure Cake	45	20	47	30	26	5.4	6.3	5.5	–	1.2	0.56	0.038	0.47	0.48
Turkeys, Breeder: Whole Litter	35	7.6	47	18	72	4.6	7.4	4.3	–	1.0	0.43	0.031	0.50	0.40
Ducks, Whole Litter	17	3.6	21	13	22	3.3	3.0	3.0	–	1.3	0.37	0.021	0.32	0.04

Table Key

Preparing Samples

Always prepare your samples from six to 12 representative areas in the poultry house or from at least six different locations in the stockpile. (Samples collected from the stockpile should be taken from a depth of about 18 inches; careful handling will ensure that no soil is intermixed in the sample.) Samples should be taken as close as possible to the time of application; however, allow sufficient time to receive test results.

To collect the sample, obtain a quart of waste from six to 12 locations in the house or stock pile and place them in a large, clean bucket. Mix the contents thoroughly; then place about a quart of the mixed sample into a clean plastic bag or bottle. Seal it tightly, but allow room for the sample to expand. Keep the sample cool; if it is not mailed to the laboratory on the same day as it was withdrawn from the source, then the entire sample should be refrigerated. The accuracy of the lab test depends on the quality of the samples collected. Contact the lab that will be analyzing your sample for information on collection, handling, and shipping.

For Best Results

Both dry and wet samples should be routinely tested on an “as is” basis for total nitrogen, ammonia-nitrogen, phosphorus, and potassium. The key to successful land applications is to apply the right amount of nutrients at the right time, using the right method so that the waste’s nutrient content is closely correlated with the nutrient needs of the plants and soil. Be aware that some nutrients will accumulate in the soil and reach high levels; apply the product immediately before planting, during a high growth season, and not in bad weather (when the nutrients may be washed away). Incorporate waste into the soil, if possible. For best results, use biennial soil tests in connection with your manure sample and basic calculations.

Land Application Rates and Methods

Whether the poultry manure or litter waste is taken to nearby farms or spread on your own land, the amount applied, the timing of the applications, and the methods used will affect the outcome. Understanding how the soil and manure or litter interact and calibrating the spreader will help growers apply the right amount at the right time in just the right way.

Manure spread on the surface and not worked into the soil will lose most of its volatile nitrogen compounds, which will be released as ammonia gas to the atmosphere. This release may or may not represent a pollution potential, but such lost nutrients are not available for plant growth.

Poultry waste spread on frozen or snow-covered soil has a high potential for runoff to surface water. It should not be surface applied to soils near wells, springs, or sinkholes or on slopes adjacent to streams, rivers, or lakes. In fact, some states prohibit this activity. Conservation practices can reduce runoff, nutrient loss, and pollution.

Water pollution potential can be decreased, and the amount of waste nutrients available to plants can be increased, by working poultry waste into the soil either by tillage or by subsurface injection. Subsurface injection of waste only minimally disturbs the soil surface and would be appropriate for reduced till and no-till cropping systems.

Manure or litter must have time to break down before the nutrients in it become available to the crop. Fall applications allow this breakdown to occur, but some of the nitrogen in the manure may be lost through leaching and runoff. Spring applications prevent this nitrogen loss but do not allow enough time for the breakdown of the manure. Incorporation of poultry waste beneath the soil surface in the fall is a way to conserve the nutrients and protect water quality.

Spring and summer applications are recommended based on plant uptake, though it is always important to check for good weather before applications are planned. If litter is applied in bad weather, nutrients may be lost in stormwater runoff. Nutrient-enriched runoff from agriculture could be a leading cause of nonpoint source pollution.

How the poultry waste is applied also affects how quickly the nutrients are incorporated. Generally, incorporation within 12 hours is ideal. The waste can be broadcast over the whole field, followed by incorporation tillage. This method has the advantage of good distribution; because it is visible, the grower can determine the uniformity of the broadcasting. There will, of course, be some odor on the day of the application. Farmers may also want to investigate incorporation, topdress, sidedress, and band application methods.

Spreader Calibrations

Calibration of the spreader machine is also necessary to monitor and control the amount and uniformity of the application. Calibration specifies the combination of settings and travel speed needed to apply nutrients at a desired rate. By knowing a spreader’s application rate, and using a few basic calculations found in various fact sheets, a producer can correctly apply the nutrients to meet the needs of the plants. Generally, there are two types of nutrient spreaders — solid or semisolid and liquid. Broiler growers handle solid or semisolid nutrients; many egg producers have liquid waste systems.

Solid or semisolid waste is usually handled in box-type or open-tank spreaders, and the application rate is expressed in tons per acre. Nutrient concentrations in pounds per ton can be estimated, or calculated from the lab analysis. The nutrient application rate in pounds per acre must be determined, based on the tons per acre of waste application.

Liquid or slurry waste is usually handled by tank wagons or irrigation systems, and the application rate is expressed in gallons per acre. Nutrient concentrations in pounds per gallon (or pounds per 1,000 gallons) can be estimated or obtained from lab analysis and used with the application rate in gallons per acre to obtain pounds per acre nutrient applied.

The volumetric capacity of spreaders is generally provided by the manufacturer. Caution should be exercised in using manufacturer’s data for spreader volume. A more accurate and preferred approach is to calibrate your own equipment.

Assistance is available from the USDA Natural Resources Conservation Service or Cooperative State Research, Extension, and Education Service offices to calibrate your spreader. Worksheets are available to determine spreader capacity and application rate. Unless the waste has been analyzed for nutrient content and the crop soil nutrient needs are known, spreader calibration may have little effect on the application’s success.

Once the desired application rate is obtained, record the pertinent information so that you do not have to recalibrate the spreader each time it is used. Spread poultry wastes in a uniform manner. If lush, green growth and not-so-lush growth of plants are observed, adjustments will need to be made during the next application. Calibration of the nutrient spreader is an important practice that is economically and environmentally useful.

A nutrient management plan should be periodically updated to ensure its effectiveness. Often nutrient management can save a producer money by reducing the amount of fertilizer purchased. This reduction in cost is a result of accounting for nutrients already in the soil and manure. For more information, or for nutrient management planning assistance, contact your local USDA Natural Resources Conservation Service or Cooperative Extension Service office or a nutrient management consultant in your area.

References

Barker, J.C. 1990. Livestock Waste Sampling, Analysis, and Calculation of Land Application Rates. Reprint. EBAE 111-84. Agricultural Extension Service, North Carolina State University, Raleigh.

Brodie, H.L. and V.A. Bandel. 1990. Manure Testing. FS-430. Cooperative Extension Service, University of Maryland, College Park.

Collins, E.R. Jr., J.C. Barker, L.E. Carr, H.L. Brodie, and J.H. Martin, Jr. 1999. Poultry Waste Management Handbook. NRAES-132 Publication. Cooperative Extension Service, Cornell University, Ithaca, NY.

Fulhage, C.D. 1989. Reduce Environmental Problems with Proper Land Application of Animal Wastes. WQ201. University Extension, University of Missouri, Columbia.

———. 1992. Land Application Considerations for Animal Wastes. WQ202 University Extension, University of Missouri, Columbia.

Goan, H.C. and J. Jared. 1991. Poultry Manure: Proper Handling and Application to Protect Our Water Resources. PB1321. Cooperative Extension Service. North Carolina State University, Raleigh.

Ogburn, C.B. and J.O. Donald. 1990. Calibrating Spreaders for the Application of Animal and Poultry Manure. DPT Circular 11/90-006. Cooperative Extension Service. Auburn University, Auburn, AL.

Woodward, M. No date. Manure Spreader Calibration Work Sheet. Technical Note 4. Cooperative Extension Service, Pennsylvania State University, Lancaster.