Submitted to: Journal of Dairy Science
Publication Type: Abstract Only
Publication Acceptance Date: February 5, 2003
Publication Date: June 22, 2003
Citation: Rotz, C.A. 2003. Management to reduce nitrogen losses in animal production [abstract]. Journal of Dairy Science. 86(1):128. Technical Abstract: Reduction of N losses in animal production requires whole-farm management. Reduced loss from one component of the farm is easily negated in another component if all components are not properly managed. Animal excretion of N can be reduced by improving the balance of protein fed to that required by individual animals or animal groups or by improving production efficiency. Management to improve milk or meat production reduces the maintenance protein per unit of production, thus improving N utilization. Large losses of N occur on farms due to ammonia and nitrous oxide emissions to the atmosphere and nitrate leaching to ground water. Animal housing design and manure collection procedures influence the volatile loss in the housing structure. More frequent flushing or scraping of floors provides some reduction in loss, and experimental methods for separating feces and urine promise much greater reductions. Manure storage units are used to reduce application losses and improve the timing of nutrient application with crop needs. Maintaining a surface crust in storage tanks reduces volatile loss, and the use of covers or enclosed tanks can greatly reduce storage loss. Irrigation and surface spreading of manure without rapid incorporation often assures the loss of all remaining ammonia N. Rapid incorporation, band spreading, and shallow injection methods reduce this application loss, and deep injection into the soil essentially eliminates this loss. For grazing animals, the use of rotational grazing and half-day grazing practices can improve the distribution and utilization of manure nutrients. Reducing volatile losses between the animal and the soil can lead to greater leaching and denitrification losses if this additional N is not used appropriately. Use of a crop rotation that can efficiently recycle these nutrients and applying these nutrients near the time they are needed by the crop reduces the potential for further loss. Maintaining the proper number of animals per unit of land available for manure application is always critical for efficient recycling of nutrients with minimum loss to the environment.