pollution, commercial market, maure production, concentrated livestock production
The estimated annual value of the manure produced by livestock and poultry in the U.S. as fertilizer for farmland is around $2.5 billion. The corresponding value for manure produced in South Dakota is $172 million, which is about 5% of total cash receipts from marketings and government payments to farmers and ranchers in the state in 1992 (Taylor, 1994, p 32). These estimated manure values represent the commercial market value of the elemental nitrogen (N), phosphorus (P), and potassium (K) contained in the manure produced by livestock, as a replacement for synthetic chemical fertilizers that otherwise would be purchased and applied to farmland. Whether these values are realized in practice depends on the quality of management practices followed in handling and disposing of manure. If such management practices are sound, the actual realized values of the manure produced in the U.S. and in South Dakota will approximate the values mentioned in the above paragraph. To the extent that such practices are unsound, however, the actual realized value of manure becomes less. In the extreme, the value could become negative. The potential for negative values is accentuated for geographically concentrated livestock. With concentrated livestock production, environmental concerns can arise in connection with (1) waste run-off from feedlots ("point source pollution") and (2) nutrients leaching into soil and water from manure in excess of the nutrients required by crops and grasses ("non-point source pollution"). 1 Other things the same, possibilities for both types of pollution are greater if cattle are fed in large feedlots. 2 Point source pollution may increase because of the large amounts of feedlot waste available as potential run-off into ground and surface water sources in the immediate vicinity of large feedlots. Non-point source pollution may increase because the economic disincentives for transporting manure long distances from its point of origin may result in excessively heavy manure applications on farmland close to large feedlots (Freeze and Sommerfeldt, 1985). The results of a study of non-point source pollution for feedlot operations in South Dakota are reported in Taylor (1994).3 In this report, similar results are reported for cow-calf operations in the state.4 Special emphasis is given to comparing livestock manure nutrient loadings for cow-calf operations with those for feedlots. The comparison between cow-calf operations and feedlots is of particular interest because, on the one hand, cattle on feed are more geographically concentrated than cattle on pasture but, on the other hand, fed cattle account for only 8 % and grazing cattle account for as much as 55 % of the total estimated manure produced in the U.S. (OTA, 1990, p 93).
Taylor, Donlad and Gullickson, Gail L., "Farmland Manure Nutrient Loadings: South Dakota Feedlots and Cow-Calf Operations" (1995). Economics Research Reports. 50.