Assumptions
Manure assumptions:
- The following animals produce the majority of manure in the Mid-Atlantic region:
- Hogs and pigs (breeding and other)
- Cattle and calves (milk cows, beef cows and other cattle and calves)
- Poultry (layers, pullets not laying, pullet chicks, broilers, breeding turkeys, and slaughter turkeys)
- Sheep
- Horses
- Animal inventories on one date of the year are representative of inventories throughout the year. If inventory data are not available, the number of animals sold can be substituted if an appropriate production period is used. (We used the number of animals sold for broiler chickens and slaughter turkeys.)
- Manure coefficients (average animal weight, nutrients excreted, and recoverable manure nutrient fraction) are equivalent for all animals in the same category for the entire period of analysis.
Table of manure coefficients
- Heifers (that have not calved), steers, bulls and calves can be grouped into the category of other cattle and calves in order to maintain consistency in cattle and calf groups over the period of analysis. The average weights and amounts of nutrients excreted of "other cattle and calves" are those of steers and bulls and their recoverable manure nutrient fraction is that of feeder cattle.
Table of manure production factors
Fertilizer assumptions:
- Non-farm fertilizer use is a small fraction of total fertilizer use. (Some of the fertilizer sales data include both farm and non-farm fertilizer sales.)
- Fertilizer is applied in the county where it is purchased, and most fertilizer sold is applied to cropland during the year it is purchased.
Crop assumptions:
- The following crops account for the majority of the nutrients removed from cropland in each state. Each crop is included in every state budget unless otherwise noted.
- Corn (grain and silage)
- Sorghum for grain and silage
- Small grains
- barley
- buckwheat
- oats
- wheat
- Hay (alfalfa, other, haylage and greenchop)
- Soybeans
- Other field crops
- cotton
- peanuts
- potatoes
- sweet potatoes
- tobacco
- Fruits and berries
- apples
- grapes
- peaches
- strawberries
- o Vegetables: asparagus, green beans, lima beans, beets, broccoli, brussel sprouts, cabbage, carrots, cauliflower, celery, Chinese cabbage, sweet corn, cucumbers, eggplant, lettuce, green onions, dry onions, peas, hot peppers, sweet peppers, pumpkins, radishes, rhubarb, spinach, squash, tomatoes, turnips, watermelons
- Crop coefficients are equivalent for all crops of a given type for the entire period of analysis.
Table of crop coefficients
- Expected vegetable yields per acre are equivalent to average U.S. yields given by Maynard and Hochmuth (1997). (The U.S. Census of Agriculture only reports harvested acreages for vegetables.)
