Agriculture and Environment: Beef

Better Management Practices: Improve Waste Management

Water carries natural and chemical pollutants off of cattle production sites.

While it is often in producers' interests to reduce waste and to manage it better, it is clear that nonpoint-source pollution must be monitored and regulated. In many parts of the world, animal operations are the largest sources of pollution.

Enforcing environmental regulations
As a consequence, development and implementation of strict environmental laws and regulations to monitor and check improper discharge of the wastes from animal feedlots, barns, slaughterhouses, and tanneries will be an important factor in reducing pollution from animal operations.

Regulations could stipulate the size and the geographic distribution of feedlots based on the overall carrying capacity of a watershed or ecoregion to absorb the nutrients in feedlot waste.

Technology and waste management
The most useful regulations would also encourage the development of technology for manure treatment, use, and disposal. Waste can be managed better in areas where animals are concentrated, for example, barns and feedlot operations.

All livestock holdings should be properly equipped with wastewater treatment equipment. Regulations could also be improved and tightened with regard to the creation and treatment of wastes from slaughterhouses and tanneries. Of course, even the best environmental regulations and policies are worth very little if they are not enforced.

Sustainable operational practices
In addition to regulations, there are a number of practices that producers can adopt to reduce both total volume and nutrient concentration of the runoff from their operations. The better practice guidelines prepared by the Florida Cattlemen's Association (1999) and the Queensland Dairy Farming Environmental Code of Practice (QDPI 2001) could be adapted for other cattle-rearing regions.

They both cover farm planning and site selection; effluent collection, storage, and utilisation; on-farm carcass and rubbish disposal; riparian land management; fertilisers; and soil protection.

Examples to follow
Some specific examples of better practices include reducing the amount of water leaving a property or delaying the evacuation time to reduce off-site water quality impacts. Increased drainage also increases nutrient losses. By preventing over drainage (e.g., the drainage of wetlands, the use of drainage tiles, or the reduction of organic matter in soil which reduces water retention), the production of off-site effluent can be reduced.

Maintaining or increasing organic matter provides material to absorb water and to retain nutrients in effluent so that there is less overall runoff, the nutrient load of runoff is reduced, and runoff is spread over a longer period so that the impact at any one time is less. Structures, such as culverts or ponds, and dense vegetation can also reduce outflow of nutrients.

Sediment and vegetation that are cleaned from ditches and watercourse edges should be moved back well away from the water so that they will not pollute the water again. The creation of ponds is also a way to keep cattle out of natural wetland systems. Ponds can hold the nutrients and sediment until they settle and thus pose little threat to freshwater systems (Florida Cattlemen's Association 1999).

Microorganisms to the rescue!
Bioremediation and the use of microbial inoculants such as effective microorganisms can reduce foul odours, eliminate flies, and facilitate the breakdown of manure. Regularly spraying the floors of enclosures where cattle are confined with effective microorganisms can eliminate odour problems by facilitating fermentation. Ammonia and general decomposition cause the foul odours that are given off by manure.

Effective microorganisms reduce production of these compounds because they are used by the microorganisms to generate amino acids and other organic substances that enrich the manure and enhance its value as fertiliser. Fermented cattle manure also does not have any substances that attract flies.

Curbing groundwater pollution
Groundwater pollution due to the overload of nitrates can also be avoided because effective microorganisms can convert nitrates to amino acids, which are used in their biological processes. Amino acids dissolved in water are a major improvement in the quality of water, at least when compared to raw manure and urine.

Biogas production
The large volume of manure from cattle can be used to produce biogas. In many parts of the world, only a couple of head of cattle can provide most on-farm gas and heating needs far more cheaply than buying gas. With herds of 100 or more animals, it might be possible to generate sufficient gas to sell locally.

This practice would reduce disposal costs and would also be a good source of on-farm energy. Biogas systems also generate end-of-the-pipe, nutrient-rich effluents that can be easily captured and used to produce integrated systems of vegetables, fish, and ducks.

Credits

Extracts from "World Agriculture & Environment" by Jason Clay - buy the book online from Island Press

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