FOREWORD

The hog industry is well established in Canada, and it looks toward expanding in the future. However, this sector of Canadian economy is facing a number of issues, mostly related to environment, regarding acceptance by the public and the impact on the environment.

In the spring of 1997, Agriculture and Agri-Food Canada created a multidisciplinary task force to develop effective and economically viable solutions to the environmental issues arising from hog production.

The contribution of the Research Branch to this activity has been to collate, through the expertise of a scientific focus group from research centres across the country, the available information from the international literature.

This report presents the available information and provides a research response to the environmental challenge. I hope that it will contribute to the development of solutions for the environmental issues related to the existing and future hog production in Canada.

Frank Claydon
Deputy Minister

EXECUTIVE SUMMARY

Environmental impacts of hog production are:

• objectionable odors
• nitrogen and phosphorus pollution to water
• ammonia emission to the atmosphere.

Minimizing odor

The first steps toward reducing odors is to keep animals and facilities clean and to minimize manure exposure to the air during storage and land application. The second step is to incorporate cost-effective technologies already available to reduce odor during manure storage and land application. The third step includes research on

• the impact of diet amendment and feeding practices on odor emissions
• improving pig genetics to better utilize nitrogen, phosphorus, and other precursors to odorous compounds
• developing pig production and manure management systems that reduce odor production and dispersion.

Minimizing ammonia emission

There are four possible steps toward minimizing ammonia emissions:

• incorporate manure immediately into the soil following field application
• better balance the diet with pigs requirements, alter the diets by balancing amino acids, and/or incorporate other additives that may reduce ammonia emission
• reduce the exposure of the manure to air
• conduct research on improving diets and on developing pig production and manure management systems that minimize ammonia emission.

Determining soil suitability to receive manure

 Steps in determining soil suitability for manure application are:

• develop manure application guidelines so that manure nutrients are applied at rates not exceeding the capability of specific crops to utilize these nutrients
• develop alternative manure utilization systems for hog farms that have excessive manure in areas that are at high risk of surface or groundwater pollution
• develop "risk" maps identifying which soils or areas are at greatest risk and determining safe rates of manure application. This also includes encouraging hog production to develop in areas of least risk.

Reducing the risk of phosphorus pollution

Steps toward reducing the risk of phosphorus pollution are:

• apply manure based on the ability of crops to utilize the phosphorus and at times of the year which result in minimum pollution potential
• develop feeding systems that reduce manure P by using enzymes such as phytase, or by phase feeding
• develop alternative manure-utilization systems to produce value-added products to be exported from areas at risk of water pollution.

Toward sustainable pork production

Five major issues/considerations for sustainable pork production include:

• developing improved feeding systems, to reduce odor, phosphorus and nitrogen excretion, and ammonia emission from the manure
• improving manure storage and application methods, to effectively utilize manure as a nutrient source for crops
• establishing manure application guidelines for soil and soil suitability criteria that consider the risk of water pollution by N, P, biological oxygen demand (BOD), and bacteria, and of accumulation of metals in soil
• developing manure treatment systems that consider all environmental concerns; e.g., manure treatment systems designed to reduce odor or "remove" N and P often promote ammonia emissions
• establishing an economically viable and environmentally sustainable pork production, through development of alternative housing and manure management systems.

INTRODUCTION

On average, one hog produces approximately one ton of manure per year. Therefore, on a year-round basis, the Canadian pig population produces some 24.4 million tons of manure annually. Hog manure contains major plant nutrients and organic matter that can be utilized for efficient crop production and to enhance soil properties. However, because many production units do not often have a sufficient land base or are located away from field crop production areas, the issue of disposing of the manure adequately and in an environmentally sound manner represents significant additional costs to the industry.

• the odors that are released from the production units and the liquid manure storage facilities, and during field application
• the high concentrations of nutrients (especially phosphorus) and heavy metals building up in the soils as a result of field application of manure, especially in the areas with a large number of production facilities
• the contamination of water bodies by nutrients and bacteria.

MAJOR ISSUES RELATED TO SWINE MANURE

Odors— the common major problem related to swine production units

• odor control along the hog production line (e.g., closed systems, ventilation, feed, handling in the production unit, and storage, handling, and spreading of animal wastes)
• more efficient utilization and valorization of the animal wastes (composting, treatment, fractionation, equipment, application according to crop requirement, time and techniques of application, transportation, and new uses).

Regional Concerns

• problems related to land application of manure in conformity with environmental regulations in each province.

• problems related to land application of manure, especially the accumulation of P in the soil and the release of P and N into groundwater and runoff.

• loss of N as ammonia
• problems related to land application of manure and the incorporation of nutrients in the soil before they are lost
• problems related to bacteria spread on the land along with the manure, which often enter tile drains or surface water.

• storage of liquid manure
• hog production facilities established over shallow water tables
• land suitability to receive liquid manure, in relation to soil types and nature of the vegetation.

• impact of manure nutrients on surface and groundwater quality
• impact of swine production on air quality (NH3 emissions).

DEALING WITH ODORS

The problem

Farming operations give rise to a variety of "naturally occurring" odor problems. Odorous gases are generated by the microbial breakdown of plant and animal proteins and when manure is stored under anaerobic conditions. The main sources of odors are associated with the production, handling, and processing of animal wastes, and the problem has become accentuated with the high-density, confined rearing of livestock.

• size and type of hog production facilities
• production practices
• location of the unit and local topography
• season and climate
• time of the day
• direction and speed of the wind
• turbulence of the air.

 The complex nature of odors

• Odorous substances in animal housing are produced predominantly by volatile compounds and dust. Chemical analyses of the volatile chemicals arising from animal production have been attempted. More than 150 volatile compounds have been identified; not all compounds necessarily cause "bad" odors, and volatile compounds in the highest concentrations may not be the most unpleasant to humans. These volatile compounds originate mainly from manure slurry, wet floors, and dirty animals.
• Dust is composed of fine aerosol particles such as feed components, dried fecal material, hair, skin cells, mold, fungi, viruses, and bacteria. The dust associated with hog-production facilities amplifies the perceived odors. The concentration of some odorants may be 40,000,000 times greater on dust particles than in an equal volume of air. Dust particles are also capable of transporting odors over long distances.
• Odors from manure storage result from the anaerobic degradation of the organic fraction of the slurry. Odors are very intense during the homogenization of the content in the storage and the loading of the manure slurry spreader.
• Volatile compounds are released rapidly when manure is applied onto the land, and very strong odors are emitted in the field area. Odor emissions may reach levels that are sometimes unacceptable to the neighborhood for the serious discomfort they create.
• Another problem associated with odors is the low acceptability of manure slurry by some potential users, e.g. cash crop producers. This is a real constraint for hog farms that have to dispose of a surplus of manure. The lack of sufficient land for disposal of manure surplus often results in soil and water pollution. This issue will be addressed later.
• In some regions, the threat of odor emissions from hog operations has restricted the growth of the industry. Odor abatement is thus a major concern for hog producers. At present, there is no economical control technology available in Canada to solve the odor problems from hog operations.
• Until recently, odors were considered essentially as a nuisance problem. However, there is new evidence that odors can have also some negative effects on human health, causing nausea, headaches, sleep disturbances, upset stomach and loss of appetite, and depression. Health problems can be more serious for farm workers who are exposed continuously to odors, dust, and toxic gases. Some farm workers have developed respiratory problems such as chronic bronchitis, occupational asthma or even worse, farmer’s lung disease. Because swine operations are getting larger, more workers are being exposed to these harsh conditions.

Toward a solution

1. The first essential step to achieve odor abatement is to develop and recommend best management practices and guidelines that apply to livestock buildings and manure slurry management. For example, measures that reinforce the cleanliness of farm buildings and that recommend appropriate weather conditions and timing for land application of manure slurry would have a positive effect on odor attenuation.

Until some of the newer technologies are available to them, farmers should utilize the "Best Management Practices" already available in several provinces, for the management of the animal manure. For example:

• keeping animals and facilities clean
• adding manure from below to the storage pit
• injecting or incorporating manure below the soil surface
• applying manure when the wind is blowing away from neighbors and dwellings
• applying manure in the morning or on cloudy days
• using trees as windbreaks to promote upwards dispersion of odors.

2. The second step is to identify and recommend cost-effective technologies used in other countries that can be relevant to odor control and air quality, and that are applicable under Canadian climatic conditions and hog facilities management practices.

Some opportunities from research findings for manure storage facilities:

• Covering the storage tank can reduce odors by 90%.
• Adding alkaline material may reduce odors (e.g., by-products from power plants or cement plants can substantially reduce odors by increasing the pH above 9.5, thus reducing hydrogen sulfide emission; such a measure, however, has to be mitigated with the increased ammonia emission, discussed later).
• Adding sphagnum peat moss or other acidifying amendments to manure lagoons reduces odors.
• Manure from anaerobic digestion systems is less offensive than undigested waste.
• Bubbleless oxygenation reduces hydrogen sulfide production to non-detectable levels by GasTec Sensidyne dosimeter tube.
• A floating permeable blanket can allow a 90% reduction in ammonia and hydrogen sulfide.

Some opportunities from research findings for land application of manure:

• Manure would be either injected or incorporated within 24 hours of spreading. Various injection systems are being researched for injection/incorporation of liquid manure into row and field crop systems.

3.  The third step is to establish a comprehensive short- and long-term research program.

Recommendations for the short-term

• Assess the potential impact of diet amendment and feeding practices on odor emissions.

• Because nitrogen is a key ingredient of ammonia and other odorous compounds, the higher the nitrogen content in the manure, the greater is the potential for odor emission. Research on feed conversion and odor control proceeds in many different directions:
• N levels in the swine diet may affect the volatile fatty acid composition and NH3 concentration.
• Synthetic amino acids substituted for traditional protein sources contribute to reducing excretion of N by pigs.
• Proteolytic enzymes in processing or dietary supplements increase protein digestibility.
• Dietary supplements such as zeolite, bentonite, charcoal etc. can adsorb odor. Effects of the these materials on swine growth and feed conversion efficiency need further research.
• Plant extracts, enzymes and direct fed microbials may also help to decrease odor. Yucca extracts, as feed additives, may bind ammonia and other gases and thus decrease odor emissions from slurry during storage. Beneficial effects of these additives have been shown for both hogs and poultry.
• Utilize knowledge on odor emissions, diffusion, and abatement gained from Europe and the United States.
• Knowledge of odor concentrations enables experts to establish goals and basis of comparison to improve facilities and management practices. Several techniques, e.g., gas chromatography, distillation, liquid chromatography, and specific ion traps, have been used to characterize odors and to identify its constituents. The human nose is one of the best available odor detectors in the absence of standard methods for measuring hog odors. Dynamic olfactometers dilute pungent air to different concentrations with odor-free air, and the human nose is used as the measuring device.

• Measure the efficiency, adaptability, and economics of existing technologies under local conditions.
• Evaluate the usefulness and reliability of manure slurry additives by standard methods. Such tests will indicate if an additive has disadvantageous side effects on air, soil, and water quality. For example:
• A 68% reduction in ammonia concentrations was observed in piggeries using De-Odorase ©, but in the absence of ventilation rates, absolute ammonia emissions rates could not be calculated.
• Added to the diet of grower pigs, De-Odorase © reduced significantly the concentration and emissions of NH3 by 26%, but did not significantly affect the odor concentration or emissions and did not influence the rate of weight gain.

Recommendations for the long-term

The long-term activities should be oriented toward the development of solutions that have excellent potential to substantially reduce odor emissions and atmospheric pollution, as well as improving the working conditions inside the farm buildings. For example:

• gaining a better knowledge of odor emissions and dispersion mechanisms, to quantify the influence of a wide range of animal management and environmental factors and to recommend distance regulation based on operational features and geographical locations
• studying animal genetics, to develop animals more efficient in using nitrogen, phosphorus, and odor-producing compounds
• developing effective and economic technologies to deodorize swine manure slurry and reduce its negative impact on air, water, and soil quality
• finding a reproducible methodology for assessing manure odors in the laboratory.

 

DEALING WITH AMMONIA EMISSIONS

The problem

Ammonia emissions from hog manure contribute a significant loss of N. A computer model of the fate of excreted N, developed in south coastal British Columbia for their specific types of waste management and climatic conditions, demonstrated that over 40% of N excreted from hog production is lost to the air from the barn, during storage, and following field application. In that area, hog manure is generally stored under the barn or in concrete pits. The model showed that improving animal diets was the most effective method to reduce NH₃ emissions. In North Carolina, the Division of Air Quality estimates an 85–95% loss of N from hog manure facilities. In Denmark, agriculture contributes about 93% of the NH₃ emission, with 35, 20, and 40% of the NH₃ volatilization coming from animal houses, manure storage facilities, and following land spreading of the manure, respectively. Danish manure storage systems are typically under the barn or in concrete tanks.

Ammonia itself has a short residence time in the air. It may be redeposited in dry deposition as NH₃ close to the source (6–14%). Alternatively, it may be converted to NO (<1%) and form particulates of ammonium nitrate or ammonium sulfate (86–94%), which can travel distances of up to 2500 km. Most of the NH₃ is redeposited close to the source of production. In Denmark, more than 85% of the NH₃ is redeposited within 100 km of the source, with 75% and almost 100% of the redeposition occurring within 4 km from the source during the day and night, respectively. In the Netherlands, N deposition corresponded to 68 and 42 kg N ha^-1 at distances of 75 and 700 m from a poultry barn. NH₃ volatilization has therefore a significant effect on N supply in neighboring nutrient-poor ecosystems.

Ammonia emissions cause direct ecological and human health concerns, in addition to poor nutrient accountability and nutrient recycling. Ammonia and ammonium particulate deposition is causing eutrophication problems in surface waters and on soil ecosystems. Ammonia is a localized pollutant not likely acting as an atmospheric toxin; however, it is a precursor for ammonium particulates or aerosols, which are delocalized pollutants. Aerosols of ammonium nitrate and ammonium sulfate are particles less than 2.5 m in diameter. These particles have been suggested to pose a significant health risk to human health with increasing atmospheric particulate concentrations. Particles of this size bypass the normal defenses of the respiratory system. The amount of NH₃ that combines with airborne acidic nitrates and sulfates to form aerosols depends on the concentration of these compounds in the air. Acidic nitrates and sulfates are produced by industry and automobiles. For example, the areas near Los Angeles and Vancouver have been noted to have significant quantities of ammonium nitrate and ammonium sulfate aerosols because of the close proximity of intensive animal production units to urban centres. In the eastern Fraser Valley of British Columbia, aerosols of ammonium nitrate and ammonium sulfate were measured to be up to 70% of the fine particulates during the summer, and have resulted in visibility impairment.

Toward a solution

Ammonia emission and its control

As discussed above, it is sometimes difficult to distinguish ammonia emission from the barn from emission during storage because, on some farms, storage pits are directly below the barn. In a recent European study, NH₃ emission from pig barns was estimated at 37–40% of the excreted N. Using an N budget approach on a hog facility in Ontario, it was estimated that 43% of the excreted N was lost from the facility, primarily as NH₃. Direct measurements of NH₃ emission from hog barns in Ontario have shown a 9–19% loss of excreted N. In terms of animal mass, the NH₃ flux ranged from 4.6 to 7.0 mg N h^-1 kg^-1, a figure comparable to estimates of 2.5–6.5 mg N h^-1 kg^-1 from pig facilities in Scotland.

Much of the excess dietary protein is excreted in the form of urea. Urea hydrolysis starts immediately on the barn floor, causing a pH increase that results in NH₃ emission. With dairy cattle manure, NH₃ emission was highest during the first 24 hours following excretion. Ammonia emission from manure depends on the animal diet and on the exposure of manure to the air. The rate of NH₃ emission from the manure is related to temperature, air exchange, pH, depth of manure, and the length of exposure.

Improving the diets, particularly the protein content

• Phase feeding to balance amino acids in the diet is the primary strategy to reduce NH₃ emissions during hog production; this can be achieved on most existing production facilities and is one of the most effective strategies for reducing NH₃ emission.
• Improving diets has demonstrated a 26% reduction in N excreted, which also resulted in a 25% reduction in NH₃ emitted.
• Inclusion of bacterially fermentable substrates in the ration reduced NH₃ emissions by 18% during pig finishing.

Decreasing the exposure time of the animal excretions with the air

• Frequent barn cleaning using manure scrapers with separate urine channels is effective; this least cost conventional manure management system resulted in low NH₃ emissions.
• Using slurry collection pans contributed to a 30% decrease in NH₃ emission. A combination of improved diets, phase feeding, and optimal housing reduced NH₃ emission from the barn by 45%, compared with conventional feeding and housing systems.
• Deep bedding facilities for growing and finishing hogs may help reduce NH₃ emissions by 70%, compared with conventional housing, but with a net increase in N₂O, a major contributor to global-warming gas emission.

Ammonia emission during manure storage

Exposure of manure to the air is the primary factor in NH₃ emission. Unlike liquid dairy cattle manure, hog manure rarely forms a crust during storage, which results in high NH₃ emission rates. N losses in the United States during storage and handling were estimated at 60–80% from anaerobic lagoons and 30–65% from underground pits with liquid spreading. N losses of up to 95% were observed in the eastern United States in lagoon storage of liquid hog manure.

Several recommendations may be effective:

• Reducing NH₃ losses during manure storage may require a large investment for changing storage systems. In a laboratory experiment, NH₃ volatilization losses of 24% of manure total N were recorded with the use of artificial covers on liquid hog manure, compared with a 76% loss with uncovered storage. In Canada, most new hog operations in the Prairies are accompanied with large lagoons for storage. In contrast, in the Netherlands, the trend is to store liquid hog manure in enclosed pits or containers in order to minimize NH₃ loss.
• Sphagnum peat moss, sulfuric acid, and phosphoric acid contribute to reducing NH₃ emission from stored pig slurry by at least 75%.
• A covering of straw or plastic reduces NH₃ emissions by 65–70% and 77–84%, respectively, and a covering of mineral oil on the slurry reduces NH₃ emission by 34% to 90–95%.
• Reductions in NH₃ emission during fattening pig manure storage have been achieved by addition of organic acids, by manure additives, by cooling the manure, or by separation, aeration, and recirculation.
• Composting of separated hog slurry solids, solid hog manure from shallow or deep bedded hog facilities, or slurry bulked with peat or straw has been promoted as a more environmentally sustainable manure management system. However, significant emissions of NH₃ and N₂O are produced during composting of hog wastes.

 Ammonium-N constitutes up to 90% of the N in anaerobically stored hog manure. Following field application, pH increases when short-chain fatty acids are oxidized. This pH increase, in combination with exposure to the air, results in a loss of N as NH₃. Ammonia emission increased when manure is applied on impervious soils, on high pH soils, and under climatic conditions with higher temperatures and greater wind speed. A wide range of values were reported: up to 90% of the ammoniacal N fraction of the manure may be lost following application to the field. In France, NH₃ emission losses from pig slurry applied to grassland or arable land ranged from 37 to 63% of the ammoniacal N in the slurry, with 83% of the emission occurring during the first 6 hours when the manure was applied at midday. Between 25 and 50% of the ammoniacal N applied in pig slurry was volatilized during the first 1.5–4 hours following application. In the Netherlands, loss of the ammoniacal N fraction of pig manure as NH₃ amounted to 36–78% following application to pasture. In the United Kingdom, 24–39% of the NH₃ lost was emitted during the first hour and 85% of the loss occurred during the 12 hours following application of slurry. All these values indicate a significant loss of N.

• An effective and easily achievable strategy to reduce NH₃ emission is improved manure application, either by injection or immediate incorporation on arable soils, or using a sleigh foot on grasslands. Immediate incorporation of the hog manure is the most effective method of reducing NH₃ loss following field application of the manure. Tilling the soil before manure application also reduced NH₃ emission. Ammonia emission was 1.5 times higher following slurry application to grassland than application to arable land. Use of a sleigh foot type manure applicator on grassland has demonstrated significant reductions in NH₃ emission, and higher recovery of manure N in the grass.

 

DEALING WITH SOIL/LAND SUITABILITY FOR MANURE UTILIZATION

Hog manure should be regarded as a resource, and its management and utilization would be approached accordingly. Application to cropland is one of the most obvious methods of recycling plant nutrients. Plant nutrients removed from the soil in the harvested product fed to the animals are then returned in part to the soil as manure. The availability of plant nutrients from manure depends on its composition and on other factors such as management practices and soil characteristics.

Land suitability for receiving liquid manure must take into account several parameters:

• Heavy-textured soils have low permeability and promote low rates of decomposition, hence the rate of manure application should be lower compared with coarse-textured soils that are highly permeable and promote rapid decomposition of manure.
• High application rates of manure to coarse-textured soil may contaminate groundwater through the leaching of nutrients, whereas high application rates of manure on heavy-textured soil may be beneficial because of the high nutrient-holding capacity of these soils.
• Manure should not be applied on snow or frozen ground, particularly when the land is subject to rapid spring run-off.
• Heavily manured fields should not be summer fallowed, to avoid leaching of N and the possibility of groundwater contamination.

Heavy application of manure has been shown to increase NO₃-N, available P, and exchangeable K and Na more rapidly than inorganic fertilizers. Manure application also results in accumulation of NO₃-N and extractable P and Na in the subsoil. The level of accumulation increased with the rate of application. Hog manures have a lower N-to-P ratio than crop plants. Thus when N is supplied through manure to a crop, more P is applied than is required by the plants, and this may result in leaching and runoff of P. This point will be discussed in more detail later.

The intensity of NO₃-N leaching following heavy application of manure depends on factors such as the rate and the period of application, the soil type, type and duration of crops grown, and rate and amount of precipitation. In temperate regions, NO₃-N concentrations in the soil solution are generally highest in May and decline during the growing season because of N uptake by the crop and leaching. The fate of manure N is influenced also to some extent by the carbon content of the manure. Thus increasing C in manure may increase the level of denitrification in the soil and can reduce the potential for nitrate contamination of groundwater. In Quebec, maximum concentration of NO₃-N occurs in late June and July. Denitrification is not particularly C-dependent in cool and humid regions, and it proceeds as soon as anoxic conditions are prevailing. N₂O emission is important soon after fertilizer addition, or in the 20 days following manure application. Volatilization here is much more important than denitrification, which would represent only 2–5% of the losses. Leaching of soluble nutrients, especially NO₃-N, to lower parts of the soil profile may be of greater concern when manure is applied by injection than when broadcast on the soil surface, depending on the accessibility to soil macropores.

Toward a solution

• Additional considerations would improve the management of both soils and manures, and provide for environmental protection. For example, developing recommendations on soil-based application rates would be valuable for producers and commercial contractors, and would ultimately benefit the general public. Appropriate resource information using GIS techniques could be combined with data on volume and quality of manure to achieve this objective.
• Information on the capacity of soil to assimilate hog manure is limited. Research focus was more on technologies related to processing, handling, reducing, and applying manure. Existing soil and crop information can be used to develop soil-manure loading rates in the form of "risk" maps, in terms of soil, landscape, hydrology, temperature, precipitation, crop type and cropping practices, quality of manure, and time of application. Guidelines for the utilization of hog manure to sustain and enhance the productivity of agricultural and non-agricultural soils, and to provide an option for hog producers to dispose of a resource by-product, will have major impact on land management and cropping practices. Risks for loading rates can be developed.
• An objective will be to establish guidelines for rates of application based on the fate of the material applied, in order to optimize the utilization of nutrients and to minimize losses through leaching, to minimize salt and metal build-up in the soil and to protect groundwater.
• Multi-disciplinary projects bringing together the required critical expertise in areas of environmental geochemistry, landscape pedology, soil physical chemistry and microbiology will contribute significantly to the solution of the problem.
• Detailed knowledge of soil types, their chemical, physical, biological, and mineralogical characteristics as well as their spatial variability, and local climatic conditions can be used to identify probable soil-plant relationships and potential productivity.
• Research protocols should focus on the efficient use of manure as a soil nutrient enhancement, and methodologies would incorporate soil and landscape information such as soil permeability (texture and thickness), pH, organic matter content, soil temperature and moisture, and risk of surface runoff, as well as rate of biodegradation and quality of the manure (for example, nutrient and salt status and micro-element and heavy metal contents).
• Soil resource information from several provinces has been compiled into standard digital data bases suitable for analysis and display using geographic information system (GIS) technology. Soil information for Agro-Manitoba is now digitized, and is managed in standard formats for use and application in a GIS environment. Such a database can be used to facilitate extrapolation of management recommendations to farm fields and landscapes.

DEALING WITH PHOSPHORUS ISSUES

Traditional application rates are based on N needs for the crops. This has led often to an increase in soil P level in excess of crop requirements because of the greater N-to-P ratio (average ratio of 4:1) in manure than taken up by the crops (major grain and hay crops ratio of 7:3). The problem of P accumulation in the soil is different in each part of the country. The amount of hog manure is not exceedingly abundant in the Atlantic Provinces. Phosphorous levels are a problem in Ontario, Quebec, and British Columbia. Most of the hog producers in Quebec and British Columbia do not have an adequate land base to use all the manure in an environmentally acceptable manner. Some 3000 Quebec farms are in this situation. There is a sufficient land base on the Prairies to handle the manure. Soils are considered deficient in N and P, and require annual inputs of both nutrients for optimal crop growth. The calcareous nature of these soils restricts inorganic P mobility. However, inadequate manure management creates a risk of surface water contamination by P through surface runoff on sloping land. Furthermore, excessive application of manure may increase the risk of downward movement of organic P to shallow aquifers.

 The problem

Studies conducted in watersheds with a high concentration of hog production units in Quebec have shown a large increase in bioavailable P content in the soil and a decrease of the P sorption capacity of soils on the hog farms. Concentrations of P much in excess of the 0.03 mg L^-1 threshold value were found in drainage outlets and stream and river waters. At least six watersheds in the province of Quebec have a surplus of over 1 000 000 kg of N and P in comparison to crop needs. Application rates in excess of crop need lead to soil enrichment and filling of a significant part of the soil retention capacity. Increases of over 1000 kg ha^-1 in the plow layer, 275 kg ha^-1 in the B horizon, and 500 kg ha^-1 in the C horizon were measured in hog farm soils, compared with the forest soils in the Beaurivage watershed in Quebec. Sediments of the Boyer River watershed, very important for smelt spawning, are saturated with P. A significant relationship between the amount of suspended solids and the total river P concentration at the outlets was found in 16 major rivers in the St.-Lawrence Lowlands. This suggested that erosion from P-enriched soils was an important process along the slopes, although preferential infiltration in level tile-drained soils was also important.

On the Prairies, there is a need for nitrogen and phosphorus to sustain crop production. In calcareous prairie soils, soluble inorganic phosphates react quickly with calcium and magnesium to become immobile. However, only 40–50% of the P in manure is mineralized during the first year following application. Poorly managed manure application poses a risk of pollution to surface waters from phosphate runoff on sloping land or from leaching of organic phosphate into shallow aquifers.

Toward a solution

• Addition of phytase to hog diet may increase the utilization of feed P by 50 to 70%, and reduce the requirement of mineral P supplements (mono- and dicalcium phosphate) in hog rations.
• Cellulase addition and improved processing techniques may decrease manure P content by 5–30%.
• Adjusting feed composition to meet the nutrient requirements at defined stages of growth will decrease P excretion. However, this may have some impact on maximum animal growth.
• Increasing feed digestibility by processing techniques will reduce the excess nutrients fed to achieve maximal growth and thereby decrease excreted P by up to 5%.

•  New guidelines are needed to apply liquid manure on a P rather than on a N basis. This will result in more land being necessary to dispose of the same amount of manure.
• Site-specific soil tests, based on soil type characteristics important for P movement (e.g., slope, Al content, tile drainage, and susceptibility to soil cracking) are needed. Soil information system and GIS technology may assist in developing an integrated computerized decision-making support system that can be used easily by agronomists and farmers.
• Manure management on a watershed basis, run by farmers’ associations, will be needed to coordinate and priorize the use of manure over all other sources of nutrients. Soil-specific rates have to be identified, and long-term impacts of repeated additions monitored.
• Removing the solids (5% in volume) from hog manure would reduce the phosphorus content by 50%. The liquid phase could be further treated to obtain a concentrated solution.
• Reaction with aluminum sulfate to precipitate the phosphate, as it is done with urban sewage sludges, could transform manure P in very sparingly soluble forms to be added to the soils without enriching them to a large extent in other labile nutrients. The long-term bioavailability of such compounds has to be investigated.
• An alternative is to raise pigs on litter with a high C-to-P ratio or to add liquid manure to carbon-rich materials (e.g., wood chips and pulp and paper sludges) in order to produce composts to be used off-site to restore soils with low organic matter content.

• Spreading of liquid manure in the fall without incorporation should be banned, as any significant rainfall would result in large contamination of water and sediments.
• Calibration of manure spreading equipment is necessary to ensure the addition of adequate amounts of nutrients.
• Strip-cropping systems using perennial grasses or planting of multi-storied hedgerows to act as buffers along waterways have great potential to reduce P contamination by runoff on sloping land. Such systems may also remove P from lateral subsurface water flow on shallow soils and retain windblown particles.
• Minimum tillage may reduce P losses by runoff on sloping land and increase P uptake in the Prairies where drainage water P losses are limited.
• Strategic N application in ammonia form is known to increase P uptake either directly or by increased soil P solubility.
• Recommendations would be based on the use of residual soil phosphorus coupled with small amounts of starter soluble P.
• Use of companion crops in spring cereal production may allow safe manure fall application in areas of low rainfall.
• Use of crops with high P uptake (for example, silage corn in areas with >2500 CHU, or canola in cool climate areas with < 2500 CHU).
• Use of alternate crops such as forage or forests (e.g., Sugar maple) should also be investigated.

• Conservation tillage can reduce soil and P transfer in surface runoff, although the proportion of P that is bioavailable both in soluble and particulate forms may increase. Consequently, eutrophication-agricultural management decisions should evaluate and consider total and bioavailable P loss from the manure.
• Use appropriate methodology to estimate P bioavailability as both soluble phosphorous (SP) and bioavailable particulate P (BPP) essential to more accurately estimate the impact of hog manure spreading or agricultural management practices on the biological productivity of surface waters.
• Evaluate potential response to soil residual P from manure-amended soils in combination, with or without rotations after short- or long-term manure applications.

RESEARCH CONTRIBUTION

• Establish standardized methodology for evaluating additives, air, soil, and water quality and offensive odors.
• Improve practices for land application of manure to reduce NH₃ emissions.
• Reduce NH₃ losses during storage.
• Develop manure management guidelines that incorporate information on the interaction between, for example, the soil and manure nutrients, impact of soil characteristics, seasonal factors, mineral interactions, surface and subsurface water movement.
• Investigate the effect of addition of carbon-rich materials to manure slurries to improve the handling characteristics of the manure nutrients.
• Evaluate adaptability and economics of implementing existing technologies.
• Evaluate phase feeding, diet composition, and diet amino-acid balance to reduce manure ammonia emissions, modify manure composition, and reduce odors emanating from the manure.
• Separate manure liquid and solids, and compost the solids to reduce gas emissions.
• Modify the hog facility design to improve manure management and control gas emissions.
• Obtain information on cycles for the nutrients present in manure and the effectiveness of their use by annual crops (also a longer-term research objective).
• Identify crops that, under Canadian climatic conditions, use nutrients in the fall, because they would allow fall application of manure and therefore decrease the total storage period.
• Continue evaluating soil types and their suitability for various methods of application.
• Increase the efficiency of utilization of dietary phosphate (phytase, cellulase, and dietary formulation) to decrease the over supplementation to meet basic requirements.

Hog production, an industry with a value in excess of $2 billion, is found in all parts of Canada. It is increasing, but not at the same rate in all provinces. Overall, hog production in 1995 was 7% greater than in 1994, and much of the production is going to the export market. About 30% of the Canadian production has been exported to 55 countries, and the potential for increased hog production is real. Any increase in production will also increase the requirements for feed production, feed quality, housing, manure storage, land to spread this manure, and the ability to deal with more people affected by the hog-raising environment.

• odor production from hog production facilities and manure storage
• air pollution
• land suitability for manure application
• phosphorus accumulation on land where manure is spread. These problems can be considered as short-term problems that have a possibility of significant progress being made over the next four years. Impact of hog production on water quality has also been referred to as an issue.

• feeds and feeding
• hog buildings
• hog health
• manure production and storage
• manure odors and gas production
• manure handling and spreading for the conservation of valuable nutrients
• cost effective ways of processing and /or packaging manure for subsequent usage
• impact of manure on the environment.

In order to be successful, this approach will require the participation of the private sector, producers, and agricultural engineering, along with the research groups.

• Develop feed systems to maximize growth, minimize feed costs, and maximize profits to the producers. Producers are looking for ways of optimizing production efficiency. Other problems can be addressed through diet formulation.
• Modify the amino-acid balance in rations to reduce nitrogen levels in feces of dietary origin. Increasing the efficiency of animal feed can decrease feed costs and the amount of manure that must be handled. Modified composition of the manure will have implications for the types of fermentation that develop in the manure pit, the odors (the compounds responsible are by-products of manure ingredients), and the gas production (gases are fermentation by-products of, for example, manure nutrients and mineral recycling).
• Consider mineral complexes. Minerals in feeds are normally in the form of organo-mineral complexes. Mixing feeds may cause new organo-mineral complexes to form, which may make certain minerals less available to the animal and also make those same minerals in manure less available to the plant in the field.

• The key factor is adequacy of ventilation. Hogs have very specific requirements for adequate fresh air. This is essential for maintaining animal health, regulating body temperature, minimizing dust in their atmosphere, maintaining growth rates through well regulated metabolism, etc. Most of the technology concerning this part of the environment is understood, but they have to be applied to have the desired effects.

• Consider storage facilities. Much work has gone into establishing the proper conditions for storage of manure. Many different types of storage systems are available depending, for example, on the type of barn, the number of animals, the natural topography, and the annual rainfall. The main issue is the correct type and size of storage facility for each operation. Cost is a major factor.
• Storage and separation of manure is a factor. Storage of liquid manure requires storage and handling of large quantities of water for much of the year. If the manure is separated into liquid and solid fractions, each will be handled differently. The liquid can be concentrated, fermented, dried, used as a hydroponic medium, added to irrigation water, etc. The solids can be dried and stored at much less cost, composted, bagged, and spread with conventional equipment.
• Combine other wastes with manure in the storage pit. Many wastes from forestry, fisheries, and agriculture may be effectively combined with manure to increase the stability of the manure or to add more nutrients to the final product.

Apply manure in the fall effectively. When the crops stop growing in the fall, application of manure is likely to have the nutrients lost with rain and surface runoff, and with spring snowmelt. Hog producers need to empty their manure storage tanks in the fall to accommodate the winter and spring production. Annual storage requirements can be as much as 9 months in some parts of Canada. This problem requires crop species that will tolerate some frost and grow late into the fall, in addition to determining the optimum time and method of spreading fall manure.

Assess the impact of soil and weather conditions on loss of manure volatile components. The impact of factors like temperature, time of day, impending precipitation, wind, relative humidity, soil type, soil surface, topography, type of manure, cropping, type of spreading equipment, and size of tractor can play a significant role in determining the efficacy of manure application.

Assess the accumulation of manure borne bacteria. The impact of bacteria of animal or environmental origin that are spread with the manure is not well understood. Do they have long-term accumulated impacts on the soil and/or crops? Are the pathogens anaerobic and hence killed when spread into an aerobic environment? Is composting necessary to save re-infecting animals fed the crops that are fertilized with their own manure?

• Consider the handling of the water portion of liquid manure. This portion of the manure contains high quantities of soluble nutrients which are readily available to plants and easily moved in the environment with surface water. As processes are developed for separating the liquid and solid portions of the manure, techniques for transporting and applying this water must also be addressed.
• Evaluate the potential for soluble nutrients and other elements (e.g. Zn and Cu) to enter the groundwater. Much of the basic data on movement of water and dissolved chemicals through different soil types is known. This needs to be summarized in an easily understandable form and presented to producers so that they will not unwittingly contaminate their groundwater. This will also have implications for human water supplies and recycling of nutrients to livestock.
• Assess the handling of nutrients that may be part of surface water and runoff into adjacent fields, farm dugouts, or environmentally sensitive streams and rivers. This will involve studying factors like time of application, carrying capacity of soils, height of the water table, rate of incorporation of water into the soil matrix, metabolic activity of the soil, mineral interactions, and soil pH.

 

CONCLUSIONS

• Minimizing NH₃ emission during hog production must occur using a system approach, that takes into account both the economic viability and the environmental sustainability. Environmental sustainability is concerned with NH₃ and greenhouse gas emission, odor, and surface and ground water contamination by nitrates and BOD. Most hog production facilities have been designed with little consideration of a cost-effective manure management based on maximizing the nutrient value of the manure and minimizing the negative environmental impacts. Considering that the size of hog production facilities is increasing in Canada, taking into account the cost of environmentally sustainable manure management is a priority.
• Reducing NH₃ emissions from manure storage facilities and following field application may increase the cost of production through increased capital cost for storage and equipment, and by the need for additional land in order to apply the manure without increasing the potential for groundwater contamination by nitrate and phosphorus.
• Improved feeding strategies may result in slightly higher feed costs but will reduce at the same time the amount of land required to apply the manure in an environmentally sustainable manner.
• Environmentally sustainable manure management has to be part of the economic equation for hog production. This may lead to the development of alternative hog production strategies, such as group housing on bedding that can be composted and exported further from the intensive production facilities. Creativity has to be combined with the full understanding of the environmental implications of the production systems.

SPECIALIZED FOCUS GROUP MEMBERS

The following people, members of the group, participated in the preparation of the report:

Loraine Bailey, Brandon
Bruce Bowman, London
Katherine Buckley, Brandon
Roy Bush, Nappan
Robert Eilers, Winnipeg
Daniel Massé, Lennoxville
John W. Paul, Agassiz
Vernon Rodd, Nappan
Régis Simard, Ste-Foy
Christian De Kimpe, Editor, Ottawa

 

BIBLIOGRAPHY

DEALING WITH ODORS

Aerial Environment in Animal Housing - Concentration in and Emissions from Farm Buildings. Working Group Report Series - No. 94.1.

Al-Kanani, T., Akochi, E., Mackenzie, A.F., Alli, I., and S. Barrington. 1992. Organic and inorganic amendments to reduce ammonia losses from liquid hog manure. J. Environ. Qual. 21: 709-715.

Amon, M., Dobeic, M., Sneath, R.W., Phillips, V.R., Misselbrook,T.H. and Pain, B.F. 1995. Odour and ammonia emissions from broiler houses: a farm scale study on the use of De-Odorase© and clinoptilolite zeolite. In: Proceedings of the International Livestock Odor Conference ‘95, Iowa State University. October 16-18, 1995. pp. 56-60.

Anonymous. 1995. Option for Managing Odors. A report from the Swine Odor Task Force, North Carolina Agricultural Research Service, North Carolina State University. 34 pp.

Barrington, S., 1995. Zeolite to control manure odours and nitrogen volatilization. In: Proceedings of the International Livestock Odor Conference ‘95, Iowa State University. October 16-18, 1995. pp. 65-68.

Barrington, S. and Moreno, R.C. 1995. Swine manure nitrogen conservation in storage using sphagnum moss. J. Environ. Qual. 24: 603-307.

Bourque, D., Bisaillon, J.G., Beaudet, R., Sylvestre, M., Ishaque, M. and Morin, A. 1987. Microbiological Degradation of Malodorous Substances of Swine Waste under Aerobic Conditions. Applied and Environmental Microbiology, 53: 137-141

Bundy, D.S., and Greene, G. 1995. Evaluation of alkaline by-products for the control of swine odours in manure storages. In: Proceedings of the International Livestock Odor Conference ‘95, Iowa State University. October 16-18, 1995. pp. 73-76.

Burnett, W.E. 1969. Air pollution from animal wastes. Environ. Sci. Technol. 3: 744-749.

De Bode, M.J.C. 1990. Odour and Ammonia Emission from Manure Storage. In: Nielson, V.C., Voorburg, J.H., L’Hermite, P., eds. Odour and Ammonia Emissions from Livestock Farming. Elservier Applied Science, London. pp. 59-66

Donham K.J., Yeggy, J. and Dague, R.R. 1985. Chemical and Physical Parameters of Liquid Manure from Swine Confinement Facilities: Health Implications for workers, Swine and the Environnement. Agricultural Wastes 14. pp. 97-113

Dorling, T. A., 1977. Measurement of odour intensity in farming situations. Agr. Environ. 3: 109-120.

Frost, J.P. 1994. Effect of spreading method, application rate and dilution on ammonia volatilization from cattle slurry. Grass For. Sci. 4: 391-400.

Frus, J.D., Jazen, T.E. and Miner, J. R., 1971. Chemical oxygen demand of gaseous air contaminants. Trans. Am. Soc. Eng. 14: 837-840.

Goodrich, P.R., Martinez, B.C., McEvoy, T.J., Arbisi, D.S., Conover, S.P., and Lam, R. 1995. Odor reduction in swine manure using bubbleless oxygenation. In: Proceedings of the International Livestock Odor Conference ‘95, Iowa State University. October 16-18, 1995. pp. 2-4.

Hammond, E.G., Fedler, C., and Smith, R.J. 1981. Analysis of particle-borne swine house odors. Agric Envir. 6: 395-401.

Hangartner, M. 1988. Scaling of Odour Intensity. In: Measurement of Odour Emissions. Proceeding of a Workshop of the Ad Hoc EEC Group on Odours, Zurich, Switzerland, pp. 20-21.

Hartung, J., and Philips, V.R. 1994. Control of Gaseous Emissions from Livestock Buildings and Manure Stores. J. Agric. Engng Res. 57 : 173-189.

Hobbs, P., Pain, B.F., and Misselbrook, T.H. 1995. Odorous compounds and the emission rates from livestock wastes. In: Proceedings of the International Livestock Odor Conference ‘95, Iowa State University. October 16-18, 1995. pp. 5-10.

Hodgson, A.S., 1971. The elimination of odour from the effluent gases of a chicken manure drying plant. J. Agric. Engng Res. 16: 387-393.

Jongebreur, A.A. 1977. Odor problems and odor control in intensive livestock husbandry farms in the Netherlands. Agric. Environ. 3: 259-265.

Mensch, R.L., Johnson, J., and Nicolai, R.E. 1996. Evaluation of Commercial Manure Additive Odor Control Products in Deep Pit Barns. ASAE paper no. 96-4090. ASAE meeting, Phoenix, Arizona, July 14-18.

Miner, J., R. 1982. Controlling Odors From Livestock Production Facilities. Published in North Central Regional Research Publication no. 284. Midwest Plan Service. Iowa State University, Ames, IA 50011.

Miner, J. R., and Hongde, P. 1995. A floating permeable blanket to prevent odour escape. In: Proceedings of the International Livestock Odor Conference ‘95, Iowa State University. October 16-18, 1995. pp. 28-34.

North Carolina Swine Odour Task Force. 1995. Options for managing odor. Report from the Swine Odour Task Force.

O’Neill, D.H., Stewart, I.W., and Phillips, V.R. 1992. A review of the control of odour nuisance from livestock buildings : Part 2, the costs of odour abatement systems as predicted from ventilation requirements. J. Agric. Engng Res. 51 : 157-165.

O’Neill, D.H., Phillips, V.R. 1992. A review of the control of odour nuisance from livestock buildings : Part 3, properties of the odorous substances which have been identified in livestock wastes or in the air around them. J. Agric. Engng Res. 53 : 23-50.

Ontario Best Management Practices. 1994. Livestock and Poultry Waste Management.

Pain, B.F., Misselbrook, T.H., and C.R. Clarkson. 1990. Odour and ammonia emissions following the spreading of anaerobically digested pig slurry on grassland. Biol. Wastes, 34: 259-267.

Phillips, V.R., Holden, M.R., White, R.P., Sneath, R.W., Demmers, T.G.M., Wathes, C.M. 1995. Measuring and Reducing Gaseous and Particulate air Pollution from UK Livestock Buildings. Seventh International Symposium on Agricultural and Food Processing Waste. ASAE, 241-251.

Ritter, W.F., and Eastburn, R.P. 1980. Odor control in liquid swine and dairy manure with commercial products. Canadian Agricultural Engineering, 22: 117-118.

Rom, H.B. 1993. Ammonia Emmission from Livestock Buildings in Denmark. Livestock environment IV, Fourth International Symposium, University of Warwick, Coventry, England. ASAE, 1161-1169.

Schmitt, M.A., Evans, S.D., and Randall, G.W. 1995. Effect of liquid manure application methods on soil nitrogen and corn grain yields. J. Prod. Agric. 2: 186-189.

Smith, R.J. 1993. Dispersion of odours from Ground Level Agricultural Sources. J. Agric. Engng Res. 54: 187-200.

Stephens, E.R., 1971. Identification of odours from cattle feedlots. Calif. Agric. 25: 10-11.

Sutton, A.L., Kephart, K.B., Patterson, J.A., Mumma, R., Kelly, D.T., Bogus, E., Jones, D.D., and Heber, A. 1995. Changing nitrogen levels in swine diets to reduce odors. In: Proceedings of the International Livestock Odor Conference ‘95, Iowa State University. October 16-18, 1995. pp. 127-130.

Sweeten, J.M. 1989. Odor Measurement Technology and Applications: A State of the art Review. Seventh International Symposium on Agricultural and Food Processing Wastes. ASAE, 214-299.

Thomas, E.D. 1996. All about odours. In: Animal Agriculture and the Environment. Proceedings from the Animal Agriculture and the Environment North American Conference. Rochester, New York, December 11-13, 1996. pp. 214-219.

Waburton, D.J., Scarborough, J.N., Day, D.L., Mueling, A.J., Curtis, S.E., and Jensen, A.H. 1980. Evaluation of commercial products for odor control and solids reduction of liquid swine manure. In: Livestock Waste: A renewable resource, Proceedings, 4th International Symposium on livestock Wastes, Amarillo, Texas. pp. 201-203.

Welsh, F.W., Schulte, D.D., Kroeker, E.J., and H.M. Lapp. 1977. The effect of anaerobic digestion upon swine manure odors. Can. Agric. Eng. 19: 122-126.

Yasuhara, A. and K. Fuwa. 1983. Isolation and analysis of odorous components in swine manure. J. Chrom. 281: 225-236.

Yasuhara A., Fuwa, K., and Jimbu, M. 1984. Identification of odorous compounds in fresh and rotten swine manure. Agric. Biol. Chem. 48: 3001-3010.

DEALING WITH AMMONIA EMISSIONS

Aasman, W.A., Pinksterboer, E.F., Maas, H.F., Erisman, J.W., Waijers-Ypelaan, A., Slanina, J., and Horst, T.W. 1989. Gradients of the ammonia concentration in a nature reserve: Model results and measurements. Atmos. Environ. 23: 2259.

Aasman, W.A.H., Hertel, O., Berkowiz, R., Christensen, J., Runge, E.H., Sorenson, L.L., Granby, K., Nielsen, H., Jensen, B., Gryning, S.E., Sempreviva, A.M., Larsen, S., Hummelshoj, P., Hensen, N.O., Allerup, P., Jorgensen, J., Madsen, H., Ivergaard, S. and Vejen, F. 1995. Atmospheric input to the Kattegat Strait. National Research Institute, Roskilde, Denmark.

Al-Kanani, T., Akochi, E., MacKenzie, A.F., Alli, I. and Barrington, S. 1992. Organic and inorganic amendments to reduce ammonia losses from liquid hog manure. J. Environ. Qual. 21: 709-715.

Amon, M., Dobeic, M., Misselbrook, T.H., Pain, B.F., Phillips, V.R. and Sneath, R.W. 1995. A farm scale study on the use of De-Odorase^© for reducing odor and ammonia emission from intensive fattening piggeries. Bioresource Technology, 51: 163-169.

Andersson, M. 1995. Cooling of manure in manure culverts. A method of reducing ammonia emissions in pig buildings. Specialmeddelande Institute for Agricultural Biosystems and Technology, Swedish University of Agricultural Sciences, Lund, Sweden.

Berendse, F, Laurijsen, C. and Okkerman, P. 1988. The acidifying effect of ammonia volatilized from farm manure on forest soils. Ecol. Bull. 39: 136-138.

Brewer, R.L., Gordon, J., and Shepard, L.S. 1983. Chemistry of mist and fog from the Log Angeles urban area. Atmos. Environ. 17: 2267-2270.

Burton, D.L. and Beauchamp, E.G. 1986. Nitrogen losses from swine housings. Agricultural Wastes, 15: 59-64.

Derikx, P.J.L., and Aarnink, A.J.A. 1993. Reduction of ammonia emission from slurry by application of liquid top layers. In: M.W.A. Verstegen, L.A. den Hartog, G.J.M. van Kempen, and J.H.M. Metz, eds. Nitrogen flow in pig production and environmental consequences. Proc. First Int. Symposium, PUDOC, Wageningen, The Netherlands.

Gaider, K.M. 1997. Analysis of atmospheric ammonia as a potential atmospheric toxin. Atmospheric Environment Branch, Environment Canada.

Groenestein, C.M. 1993. Animal waste management and emission of ammonia from livestock housing systems: field studies. In: E. Collins and C. Boon, eds. Livestock Environment IV. Proceedings of a conference held in Coventry, UK. ASAE. St. Joseph, MI.

Hendriks, J.G.L., den Brok, G.M., and Voermans, M.P. 1995. Farrowing pens with low ammonia emission. Annual report of the Research Centre for Pig Production, No. 1.134. Rosmalen, the Netherlands.

Hendriks, J.G.L. and Vrielink, M.G.M. 1996. Acidification of fattening pig manure with organic acids. Annual report of the Research Centre for Pig Production, No. 1.148. Rosmalen, the Netherlands.

Hoeksma, P., Verdoes, N., Oosthoek, J. and Voermans, J. 1992. Reduction of ammonia volatilization from pig houses using aerated slurry as recirculation liquid. Livestock Prod. Sci. 31: 121-132.

Hoff, J.D., Nelson, D.W. and Sutton, A.L. 1981. Ammonia volatilization from liquid swine manure applied to cropland. J. Environ. Qual. 10: 90-95.

Horlacher, D. and Marschner, H. 1990. Schatzrahmen zur beurteilung von ammoniakverlusten nach ausbringung von rinderflussigmist. Z. Pflanzenernahr. Bodenk. 153: 107-115.

Katzel, R., Einert, P., Patz, G., Ritter, G. and Strohbach, B. 1995. Recovery of Scots pine stands near the former area of nitrogen emission at Lichterfelde/Britz. I. Air quality, soil conditions, vegetation and nutrient status of Scots pine stands. Beitrage fur Forstwirtschaft und Landschaftsokologie, 29: 5-9.

Kreuzer, M., and Machmuller, A. 1993. Reduction of gaseous nitrogen emission from pig manure by increasing the level of bacterially fermentable substrates in the ration. In: M.W.A. Verstegen, L.A. den Hartog, G.J.M. van Kempen, and J.H.M. Metz, eds. Nitrogen flow in pig production and environmental consequences. Proc. First Int. Symposium, PUDOC, Wageningen, The Netherlands.

Latimer, P., and Dourmad, J.Y. 1993. Effect of three protein strategies for growing-finishing pigs on growth performance and nitrogen output in the slurry and in the air. In: M.W.A. Verstegen, L.A. den Hartog, G.J.M. van Kempen, and J.H.M. Metz, eds. Nitrogen flow in pig production and environmental consequences. Proc. First Int. Symposium, PUDOC, Wageningen, The Netherlands.

Liao, P.H., Chen, A., and Lo, K.V. 1995. Removal of nitrogen from swine wastewaters by ammonia stripping. Bioresource Technology, 54: 17-20.

Lockyer, D.R., Pain, B.F., and Klarenbeek, J.V. 1989. Ammonia emissions from cattle, pig and poultry wastes applied to pasture. Envion. Pollution, 56: 19-30.

Moal, J.F., Martinez, J., Guiziou, F., and Coste, C.M. 1995. Ammonia volatilization following surface applied pig and cattle slurry in France. J. Agric. Sci. 125: 245-252.

Muck, R.E., and Steenhuis, T.S. 1981. Nitrogen losses in free stall dairy barns. In: Proc. 4th Int. Symp. Livestock Wastes ASAE, St. Joseph, Mich. pp. 406-409.

Pain, B.F., Phillips, V.R., Clarkson, C.R., and Klarenbeek, J.V. 1989. Loss of nitrogen through ammonia volatilization during and following application of pig or dairy slurry to grassland. J. Sci. Food Agric. 47: 1-12.

Paul, J.W. and Beauchamp, E.G. 1995. Nitrogen flow on two livestock farms in Ontario: a simple model to evaluate strategies to improve N utilization. J. Sustainable Agriculture, 54: 35-50.

Paul, J.W., Scott, T.A., and Barton, P.K. 1997. Ammonia emissions and nitrogen balances during poultry broiler production. Pacific Agriculture Research Centre Technical Rep. 133. Agriculture and Agri-Food Canada.

Robertson, A.M., and Galbraith, H. 1971. Effect of ventilation on the gas concentration in a part-slatted piggery. Farm Building R & D Studies. (May 1971), pp. 17-28.

Rom, H.B. 1993. Ammonia emissions from livestock buildings in Denmark. In: E. Collins and C. Boon, eds. Livestock Environment IV. Proceedings of a conference held in Coventry, UK. ASAE. St. Joseph, MI.

Schulze, E.D., de Vries, W., Hauhs, M., Rosen, K., Rasmussen, L., Tamm, S.O., and Nilsson, J. 1989. Critical loads for nitrogen deposition on forest ecosystems. Water Air Soil Pollut. 48: 451-456.

Sommer, S.G., Christensen, B.T., Nielsen, N.E., and Schjorring, J.K. 1993. Ammonia volatilization during storage of cattle and pig slurry: effect of surface cover. J. Agric. Sci. 121: 63-71.

Sommer, S.G., Mikkelsen, H., and Mellqvist, J. 1995. Evaluation of meterological techniqes for measurement of ammonia loss from pig slurry. Agric. and Forest Meteorology, 47: 169-179.

Ter Elste Wahle, E.R., and den Brok, G.M. 1996. Ammonia emission in a fattening pig house with application of a liquid top layer on the slurry. Annual report of the Research Centre for Pig Production, No. 1.146. Rosmalen, the Netherlands.

Thompson, R.B., Ryden, J.C., and Lockyer, D.R. 1990. Ammonia volatilization from cattle slurry following surface application to grassland. I. Influence of mechanical separation, changes in chemical composition during volatilization and presence of a grass sward. Plant and Soil, 125: 109-118.

Van Cuyck, J., den Brok, G., and Verdoes, N. 1993. Slurry pan: on the fire or in the pig house? Praktijkonderzoek Varkenshouderij, 7: 13-15.

Vanderholm, D.H. 1975. Nutrient losses from livestock waste during storage, treatment, and handling. In: Proc. 3rd Int. Symp. on Livestock Wastes, ASAE Pub. Proc-275, ASAE, St. Joseph, MI. pp. 282-285.

Van der Molen, J., Van Fassen, H.G., Leclerc, M.Y., Vriesma, R., and Chadon, W.J. 1990. Ammonia volatilization from arable land after application of cattle slurry. I. Field estimates. Neth. J. Agric. Sci. 38: 145-158.

Vander Peet Schwering, C.M.C., Verdoes, N., Voermans, M.P., and Beelen, G.M. 1996. Effect of feeding and housing on the ammonia emission of growing and finishing pig facilites. Annual report of the Research Centre for Pig Production, No. 1.145. Rosmalen, the Netherlands.

Verboon, M.C., and Mandersloot, F. 1993. Practical possibilities for using a straw casing as covering for slurry silos. Praktijkonderzoek, Proefstation voor de Rundveehouderij, Schapenhouderij and Paardenhouderij. No. 1.

Zebarth, B.J., Paul, J.W., Kowalenko, C.G., and van Kleeck, R. 1997. Estimation of the impact of agricultural production on water and air quality on a regional basis. (Manuscript in preparation, Pacific Agri-Food Research Centre, Agriculture and Agri-Food Canada).

DEALING WITH SOIL/LAND SUITABILITY FOR MANURE UTILIZATION

Agriculture and Agri-Food Canada. 1997. Sector Profile of Production, Trends and Environmental Issues.

Al-Kanani, T., Akochi, E., MacKenzie, A. F., Alli, I. and Barrington, S. 1992. Organic and inorganic amendments to reduce ammonia losses from liquid hog manure. Journal of Environmental Quality, 21: 709-715.

Alberta Agriculture. 1984. Swine manure as fertilizer. Agdex-440/27-1. Alberta Agriculture, Edmonton, Canada.

Azevedo, J. and Stout, P. R. 1974. Farm animal manures: an overview of their role in the agricultural environment. Manual 44. California Agricultural Experiment Station Extension Service. 109 pp.

Baidoo, S.K. 1996. Manure Management Symposium Proceedings, Winnipeg, MB. pp.161-168.

Barnett, G.M., and Pesant, A.R. 1996. The swine industry at the forefront of environment issues, Symposium Proceedings, Saint-Hyacinthe, Québec. pp. 1-9.

Beauchamp, E.G. 1983. Response of corn to nitrogen in preplant and sidedress applications of liquid dairy cattle manure. Can. J. Soil Sci. 63: 377-386.

Beauchamp, E.G., Kidd, G. E., and Thurtell, G. 1982. Ammonia volatilization from liquid dairy cattle manure in the field. Can. J. Soil Sci. 62: 11-19.

Bernal, M.P. and Kirchmann, H. 1992. Carbon and nitrogen mineralization and ammonia volatilization from fresh, aerobically and anaerobically treated pig manure during incubation with soil. Biology and Fertility of Soils, 13: 135-141.

Brumm, M.C. and Sutton, A.L. 1979. Effect of copper in swine diets on fresh waste composition and anaerobic decomposition. J. Animal Sci. 49: 20-25.

Burns, J.C., Westerman, P.W., King, L.D., Cummings, G.A., Overcash, M.R. and Goode, L. 1985. Swine lagoon effluent applied to ‘Costal’ Bermudagrass: I. Forage yield, quality, and elemental removal. Journal of Environmental Quality, 14: 9-14.

Burns, J.C., Westerman, P.W., King, L.D., Overcash, M.R. and Cummings, G.A. 1987. Swine manure and lagoon effluent applied to a temperate forage mixture: I. Persistence, yield, quality, and elemental removal. Journal of Environmental Quality, 16: 99-105.

Burns, J.C., King, L.D. and Westerman, P.W. 1990. Long-term swine lagoon effluent applications on ‘Costal’ Bermudagrass: I. Yield, quality, and elemental removal. Journal of Environmental Quality, 19: 749-756.

Burton, D.L., Younie, M.F., Beauchamp, E.G., Kachanoski, R.G. and Loro, P. 1994. Impact of manure application on nitrate leaching to groundwater. In: Proc. 37th Annual Manitoba Society of Soil Science Meeting. Dept. of Soil Sci., University of Manitoba, Winnipeg. Canada. 190-201.

Chase, C., Duffy, M. and Lotz, W. 1991. Economic impact of varying swine manure application rates on continuous corn. Journal of Soil and Water Conservation, 46: 460-464.

Elson, J. 1941. A comparison of the effect of fertilizer and manure, organic matter, and carbon-nitrogen ratio on water-stable soil aggregates.Soil Sci. Soc.Am. Proc. 6: 86-90.

Evans, S.D., Goodrich, P.R., Munter, R.C. and Smith, R.E. 1977. Effects of solid and liquid beef manure and liquid hog manure on soil characteristics and on growth, yield, and composition of corn. Journal of Environmental Quality, 4: 361-368.

Ewanek, J. 1996. Manure Management Symposium Proceedings, Winnipeg, MB. pp. 93-100.

Food and Agriculture Organization (FAO). 1993. FAO Agrostat PC. FAO Computerized Information Series Statistics. Production. Rome, 1993.

Franco, D., Pereilli, M., and Scallolin, M.. 1996. Proceedings of the International Conference on Buffer Zones, their Processes and Potential in Water Protection, Heythrop, UK.

Freeze, B.S. and Sommerfeldt, T.G. 1985. Breakeven hauling distances for beef feedlot manure in southern Alberta. Can. J. Soil Sci. 65: 687-693.

Gilbertson, C.B., Van Dyne, D.L., Clanton, C.J., and White, R.K. 1979. Estimating quantity and constituents in livestock and poultry manure residue as reflected by management systems. Transactions of the ASAE, 22: 602-611.

Hafez, A.A.R. 1974. Comparative changes in soil-physical properties induced by admixtures of manures from various domestic animals. Soil Science, 118: 53-59.

Hilborn, D. 1996. Manure Management Symposium Proceedings, Winnipeg, MB. pp.101-105.

Hoff, J.D., Nelson, D.W. and Sutton, A.L. 1981. Ammonia volatilization from liquid swine manure applied to cropland. Journal of Environmental Quality, 10: 90-95.

Humenik, F.J., Skaggs, R.W., Willey, C.R., and Huisingh, D. 1972. Evaluation of swine waste treatment alternatives. In Waste Management Research.. Graphics Corporation, Washington, D. C. pp. 341-352.

Khan, N. 1996. Feed Mix, 4:22-25.

King, L.D., Westerman, P.W., Cummings, G.A., Overcash, M.R. & Burns, J.C. 1985. Swine lagoon effluent applied to ‘Costal’ Bermudagrass: II. Effects on soil. Journal of Environmental Quality, 14: 14-21.

King, L.D., Burns, J.C., and Westerman, P.W. 1990. Long-term swine lagoon effluent applications on `Costal’ bermudagrass: II. Effect on nutrient accumulation in soil. Journal of Environmental Quality, 19: 756-760.

Klausner, S.D., and Guest, R.W. 1981. Influence of NH₃ conservation from dairy manure on the yield of corn. Agronomy Journal, 73: 720-723.

Kornegay, E.T., Hedges, J.D., Martens, D.C., and Kramer, C.Y. 1976. Effect on soil and plant mineral levels following application of manures of different copper contents. Plant and Soil, 45: 151-162.

Larson, B.G. 1991. Saskatchewan pork industry manure management recommendations. Saskatchewan Pork Producers’ Marketing Board, Saskatoon, SK. 30 pp.

Lauer, D.A., Bouldin, D.R., and Klausner, S.D. 1976. Ammonia volatilization from dairy manure spread on the soil surface. Journal of Environmental Quality, 5: 134-141.

Long, N.J., and Gracey, H.I. 1990. Herbage production and nitrogen recovery from slurry injection and fertilizer nitrogen application. Grass and Forage Science, 45: 77-82.

Lorenz, F., and Steffens, G. 1992. Agronomically efficient and environmentally careful slurry application to arable crops. Aspects of Applied Biology, 30: 109-116.

McEachron, L.W., Zwerman, P.J., Kearl, C.D., and Musgrave, R.B. 1969. Economic return from various land disposal systems for dairy cattle manure. In: Animal Waste Management. Proceedings Cornell University Waste Management Conference 13-15 Jan. 1969. Syracuse N.Y. Cornell University Press, Ithaca, N. Y. pp. 393-400.

McKenna, M.F., and Clark, J.H. 1970. The economics of storing, handling and spreading of liquid hog manure for confined feeder hog enterprises. In: Relationship of agriculture to soil and water pollution. Proc. Cornell Un. Agr. Waste Management Conference 19-21 Jan. 1970. Rochester, N. Y. Cornell University Press, Ithaca, N. Y. pp. 98-110.

Menzies, J.D., and Chaney, R.L. 1974. Waste Characteristics. In Factors Involved in Land Application of Agricultural and Municipal Wastes. USDA, ARS.

Miller, P.L., and MacKenzie, A.F. 1978. Effects of manures, ammonium nitrate and S-coated urea on yield and uptake of N by corn and on subsequent inorganic N levels in soils in southern Quebec. Can. J. Soil Sci. 58: 153-158.

Pet íková, V. 1992. Hnojení p i biologické rekultivaci d lních výsypek a slo iš popel (Fertilizer for biological reclamation of mine spoil and ash dumps). Rostlinná Výroba, 38: 327-335.Powers, W.K., Wallingford, G.W., and Murphy, L.S. 1975. Research status on effects of land application on animal wastes. Environmental Protection Technology Series, EPA 660/2-75-010. U. S. Government Printing Office, Washington, D. C. pp. 44-46.

Pries, J. 1996. Manure Management Symposium Proceedings, Winnipeg, MB. pp.119-126.

Richards, J.E., and Martel, Y.A. 1991. Agronomic management of manure - A position paper. In: Expert Committee on Soil and Water Management. Research Station, Research Branch, Agriculture Canada, Fredericton, N.B. Canada.

Safley, L.M., Jr., Lessman, G.M., Wolt, J.D., and Smith, M.C. 1981. Comparisons of corn yields between broadcast and injected applications of swine manure slurry. In: Livestock Waste: a renewable resource. Proc. Int. Symposium on Livestock Wastes, Amarillo, Texas 15-17 Apr. 1980. Am. Soc. Agric. Eng., St. Joseph, Mich. pp. 178-180.

Simard, R.R., Cluis, D., Gangbazo, G., and Beauchemin, S. 1995. Phosphorus status of forest and agricultural soils from a watershed of high animal density. J. Environ. Qual. 24: 1010-1017.

Simard, R.R., Hamel, C., and Garand, M.J. 1996. The swine industry at the forefront of environment issues, Symposium Proceedings, Saint-Hyacinthe, Québec. pp. 31-41.

Sommerfeldt, T.G., and Chang, C. 1985. Changes in soil properties under annual applications of feedlot manure and different tillage practices. Soil Sci. Soc. Amer. J. 49: 983-987.

Sutton, A.L., Mayrose, V.B., Nye, J.C., and Nelson, D.W. 1976. Effect of dietary salt level and liquid handling systems on swine waste composition. J. Animal Sci. 43: 1129-1134.

Sutton, A.L., Nelson, D.W., Mayrose, V.B., and Nye, J.C. 1978. Effects of liquid swine waste applications on corn yield and soil chemical composition. Journal of Environmental Quality, 7: 325-333.

Sutton, A.L., Nelson, D.W., Hoff, J.D., and Mayrose, V.B. 1982. Effects of injection and surface applications of liquid swine manure on corn yield and soil composition. Journal of Environmental Quality, 11: 468-472.

Sutton, A.L., Melvin, S.W., and Vanderholm, D.H. 1984. Fertilizer value of swine manure. AS-453. Iowa State Cooperative Extension Service, Ames, Iowa. 6 pp.

Sutton, A.L, Nelson, D.W., Mayrose, V.B., Nye, J.C., and Kelly, D.T. 1984. Effects of varying salt levels in liquid swine manure on soil composition and corn yield. Journal of Environmental Quality, 13: 49-59.

Tabi, M., Tardif, L., Carrier, D., Laflamme, G., et Rompré, M. 1990. Rapport synthèse, Ministère de l’Agriculture, de Pêcheries et de l’Alimentation du Québec.

Tiarks, A.E., Mazurak, A.P., and Chesnin, L. 1974. Physical and chemical properties of soil associated with heavy applications of manure from cattle feedlots. Soil Sci. Soc.Am. Proc. 38: 826-830.

Unger, P.W., and Stewart, B.A. 1974. Feedlot waste effects on soil conditions and water evaporation. Soil Sci. Soc.Am. Proc. 38: 954-957.

Vanderholm, D.H. 1975. Nutrient losses from livestock waste during storage, treatment and handling. In: Managing livestock wastes. Proc. 3rd Int. Symposium on Livestock Wastes, Urbana-Champaign, Ill. 21-24 Apr. 1975. Am. Soc. Agric. Eng., St. Joseph, Mich. pp. 282-285

Wallace, H.D., McCall, J.T., Bass, B., and Combs, G.E. 1960. High level copper for growing-finishing swine. J. Animal Sci. 19: 1153-1163.

Warman, P.R. 1986. Effects of fertilizer, pig manure, and sewage sludge on timothy and soils. Journal of Environmental Quality, 15: 95-100.

Webber, L.R., Lane, T.H., and Nodwell, J.H. 1968. Guidelines to land requirements for disposal of liquid manure. Paper presented at the 8th Ind. Water and Wastewater Conf., Lubbock, Texas (June 6-7, 1968). 13 pp.

Weil, R.R., and Kroontje, W. 1979. Physical condition of a Davidson clay loam after five years of heavy poultry manure applications. Journal of Environmental Quality, 8: 387-392.

Westerman, P.W., Overcash, M.R., Evans, R.O., King, L.D., Burns, J.C., and Cummings, G.A. 1985. Swine lagoon effluent applied to ‘Costal’ Bermudagrass: III. Irrigation and rainfall runoff. Journal of Environmental Quality, 14: 22-25.

Williams, R.J.B., and Cooke, G.W. 1961. Some effects of farmyard manure and of grass residues on soil structure. Soil Science, 92: 30-39.

Xie, R., and MacKenzie, A.F. 1986. Urea and manure effects on soil nitrogen and corn dry matter yields. Soil Sci. Soc. Amer. J. 50: 1504-1509.

Zhu, Y.M., Berry, D.F., and Martens, D.C. 1991. Copper availability in two soils amended with eleven annual applications of copper-enriched hog manure. Communications in Soil Science & Plant Analysis, 22: 769-783.

DEALING WITH PHOSPHORUS ISSUES

Barnett, G.M. 1996. Animal Waste in Canada. In: C. Chang, ed. Proc. Can. Soc. of Soil Sci. Waste Management Workshop, July 7^th 1996, Lethbridge, AB. pp. 28-45.

Beauchemin, S., Simard, R.R., and Cluis, D. 1996. Phosphorus sorption-desorption kinetics of soil under contrasting land uses. Journal of Environmental Quality, 25:1317-1325.

CPVQ. 1995. Coefficients d’efficacité des engrais de ferme. Bulletin technique 22. AGDEX 538. Québec, QC, 18 pp.

Gangbazo, G., Pesant, A.R., and Barnett, G.M. 1997. Effet de l’épandage des engrais minéraux et de grandes quantités de lisier de porc sur l’eau le sol et les cultures. Rapport de Recherche , direction des écosystèmes aquatiques, Ministère de l’Environnement et de la Faune du Québec, Québec, QC. 46 pp.

Grimard, Y. 1990. Qualité générale de l’eau au Québec. In: "Colloque sur la qualité de l’eau en milieu agricole^". Conseil des productions végétales du Québec, Québec, QC. pp. 24-37.

Ordre des Agronomes du Québec. 1996. Mise à jour sur le projet de règlement sur la réduction de la pollution d’origine agricole. 96-03-28. 6 pp.

Patoine M. 1995. Perspectives et approche du Québec pour faire face à la problématique environmentale associée à l’intensification et la concentration des élevages. In: Siting livestock and poultry operations in the 21^th Century Symposium, July 13-14 Ottawa, Canada.pp. 45-62.

Simard, R.R. 1996. Manure management in Québec: the urgent need for solutions. In: C. Chang (ed.) Proc. Can. Soc. Soil Sci. Waste Management Workshop, July 7^th 1996, Lethbridge, AB. pp. 65-80.

Simard, R.R. 1997. Étude de la qualité de l’eau, des sédiments et des sols du bassin-versant de la rivière Boyer. Rapport préliminaire, Agriculture et Agroalimentaire Canada, 17 pp.

Simard, R.R., Cluis, D., Gangbazo, G., and Pesant, A. 1994. Phosphorus in the Beaurivage River Watershed. In: R.N. Yong (ed.) Proc. Joint CSCE-ASCE Natl. Conf. on Environ. Eng., Montreal, QC. pp. 509-516.

Simard, R.R., Cluis, D., Gangbazo, G., and Beauchemin, S. 1995. Phosphorus status of forest and agricultural soils from a watershed of high animal density. Journal of Environmental Quality, 24:1010-1017.

Simard, R.R., Drury, C.F., and Lafond, J. 1996. Cropping effects on phosphorus leaching in clay soils. Better Crops with Plant Food, 80: 24-27.

Simoneau, M. 1996. Qualité des eaux du bassin de la rivière Châteauguay, 1979 à 1994. Direction des écosystèmes aquatiques. Ministère de l’Environnement et de la Faune du Québec, Québec, QC.

Sims, J.T., Simard, R. R., and Joern, B. C. 1997. Phosphorus losses in agricultural drainage: historical perspective and current research. Journal of Environmental Quality 26: (in press).

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