Quantification of nutrient and mass loss during composting is needed to understand the composting process, to implement methods for nutrient conservation, and to reduce potential adverse environmental impact. Beef cattle feedlot manure was composted in a windrow on an open concrete area in 1992, 1993, and 1994 to determine the amounts of nutrient, C, and mass loss during composting. The area was enclosed on all sides with a 0.2 m high metal sheet to direct runoff to a fiberglass tank (4000 L) during rainfall. Nutrients in runoff represented combined runoff and leaching losses. Nutrients, C, and mass loss during composting was determined by the difference between the amounts at the beginning and at the end of the composting. Nitrogen loss during composting ranged from 19 to 42% and was related to the initial manure N content. Ammonia volatilization (calculated by difference) accounted for >92% of the N loss whereas combined runoff nitrate and ammonium loss was <0.5%. Mass loss was relatively low (15–20%) while loss ranged from 46 to 62% and was basically all through bio‐oxidation. Phosphorus runoff loss, the main mechanism for P loss, was low (<2%). Manure N/P ratio decreased during composting, indicating a greater soil P buildup potential with compost application. Potassium and Na losses in runoff were high (>6.5% each) 1992 and 1993; they were low (<2% each) in 1994 due to fewer rainfall. Calcium and Mg losses were <6% each year. Nutrient and salt loss during composting resulted in reduced electrical conductivity of the composted manure. Ammonium and P concentrations in runoff would create surface water pollution if runoff was not diluted with fresh water.

Manure or compost from beef cattie feediots can be an excellent sources of nutrients and organic matter when added to soils, but they can also pollute runoff. We determined the effects of simulated rainfall on runoff losses of P and N, and EC and pH following application of manure and compost to a Sharpsburg silty clay loam (fine smectitic, mesic Typic Argiudoll) soil having grain sorghum [Sorghum bicolor (L.) Moench] and winter wheat (Triticum aestivum L.) residues. Manure, compost, and fertilizer were applied to no‐till fields at rates required to meet N or P requirements for corn (Zea mays L.) production and were either left on the soil surface or disked to 8 cm. There were also untreated checks. Runoff concentrations of dissolved P (DP), bioavailable P (BAP), and NH4‐N were significantly greater when the soil was not disked. Total and particulate P concentrations in runoff were generally less under wheat than sorghum residue and were less for the no‐till than the disked condition. In the disked system, N or P‐based manure or compost application resulted in DP concentration <1 mg L−1. Manure and compost application resulted in greater runoff EC values than fertilizer application. Phosphorus concentration of runoff receiving P fertilizer or N‐based manure and compost application can be an environmental concern when these sources are applied under no‐till conditions without incorporation.

Residual effects of manure or compost application can maintain crop yield level for several years after Residual effects of manure or compost application on crop production and soil properties can last for several years. This study was manure or compost application ceases since only a fracconducted to evaluate residual effects of annual or biennial application of the N and other nutrients in manure or compost tions of N-and P-based composted and noncomposted beef cattle become plant available in the first year after application (Bos taurus) feedlot manure, chemical fertilizer, and no-treatment (Motavalli et al., 1989; Eghball et al., 2002). Eghball check on corn (Zea mays L.) production and soil properties. Manure and Power (1999) found that 40% of beef cattle feedlot and compost were applied from 1992 to 1995, and the residual effects manure N and 20% of compost N were plant available were determined from 1997 to 1999. Residual effects of N-and P-based in the first year after application, indicating that about manure and compost applications on corn grain yield and N uptake 60% of manure N and 80% of compost N became plant lasted for at least one growing season while the effects on soil properties were longer lasting. Soil P can contribute to crop P uptake for Ͼ4 available in the succeeding years, assuming little or no yr after N-based manure or compost application had ceased. The loss of N due to NO 3-N leaching or denitrification. residual effects of manure and compost applications significantly in-Residual effects of organic materials on soil properties creased soil electrical conductivity and pH levels and plant-available can contribute to improvement in soil quality for several P and NO 3-N concentrations. Four years after the last application, P years after application ceases (Ginting et al., 2003). Inleaching to a soil depth of 45 to 60 cm was observed with N-based creased levels of soil N, P, K, pH, and C levels in the manure or compost application. No residual effects of manure and soil can increase crop yield beyond the application years. compost applications on soil NH 4-N were observed. Averaged across Soil pH, organic matter, total N, NO 3-N, and P levels years, soil total C concentrations or quantities were not different among were still elevated 4 yr after dairy manure application the treatments, indicating that total C was not a sensitive indicator. Residual effects of Nor P-based manure or compost application ceased (Mugwira, 1979; Lund and Doss, 1980). Eghball increased crop production for one year and influenced soil properties et al. (2003) found that the increased plant-available for several years.

Residual effects of manure or compost application can maintain crop yield level for several years after Residual effects of manure or compost application on crop production and soil properties can last for several years. This study was manure or compost application ceases since only a fracconducted to evaluate residual effects of annual or biennial application of the N and other nutrients in manure or compost tions of N-and P-based composted and noncomposted beef cattle become plant available in the first year after application (Bos taurus) feedlot manure, chemical fertilizer, and no-treatment (Motavalli et al., 1989;Eghball et al., 2002). Eghball check on corn (Zea mays L.) production and soil properties. Manure and Power (1999) found that 40% of beef cattle feedlot and compost were applied from 1992 to 1995, and the residual effects manure N and 20% of compost N were plant available were determined from 1997 to 1999. Residual effects of N-and P-based in the first year after application, indicating that about manure and compost applications on corn grain yield and N uptake 60% of manure N and 80% of compost N became plant lasted for at least one growing season while the effects on soil properties were longer lasting. Soil P can contribute to crop P uptake for Ͼ4 available in the succeeding years, assuming little or no yr after N-based manure or compost application had ceased. The loss of N due to NO 3 -N leaching or denitrification.residual effects of manure and compost applications significantly inResidual effects of organic materials on soil properties creased soil electrical conductivity and pH levels and plant-available can contribute to improvement in soil quality for several P and NO 3 -N concentrations. Four years after the last application, P years after application ceases (Ginting et al., 2003). Inleaching to a soil depth of 45 to 60 cm was observed with N-based creased levels of soil N, P, K, pH, and C levels in the manure or compost application. No residual effects of manure and soil can increase crop yield beyond the application years.compost applications on soil NH 4 -N were observed. Averaged across Soil pH, organic matter, total N, NO 3 -N, and P levels years, soil total C concentrations or quantities were not different among were still elevated 4 yr after dairy manure application the treatments, indicating that total C was not a sensitive indicator. Residual effects of N-or P-based manure or compost application ceased (Mugwira, 1979;Lund and Doss, 1980). Eghball increased crop production for one year and influenced soil properties et al. (2003) found that the increased plant-available for several years.P level in soil following N-based manure or compost application can contribute to crop P uptake for up to 10 yr without any additional P addition. Ginting et al. Application of manure or composted manure can (2003) did not find increased emission of greenhouse result in increased soil concentrations of nutrients gasses (CO 2 , CH 4 , and N 2 O) as a result of residual maand organic m...

Concentrations of human health-related microorganisms in runoff from agricultural plots (0.75 m x 2 m) treated with fresh and aged cattle manure, swine slurry and no manure (control) were determined. Three consecutive simulated rainfall events, producing 35 mm rainfall and separated by 24 h, were carried out for each plot. Fecal indicator (Escherichia coli, enterococci, Clostridium perfringens and coliphage) loads released in rainfall runoff from plots treated with fresh cattle manure, aged cattle manure and swine slurry treatments ranged from 5.52 x 10(5) to 4.36 x 10(9), 3.92 x 10(4) to 4.86 x 10(8), and 9.63 x 10(5) to 3.05 x 10(8), respectively. Plot runoff concentrations of protozoa (Cryptosporidium oocysts and Giardia cysts) ranged from 1.65 x 10(5) to 1.04 x 10(6), 2.93 x 10(3) to 2.75 x 10(5), and 9.12 x 10(4) to 3.58 x 10(6) for fresh cattle manure, aged cattle manure and swine slurry plot treatments, respectively. These results suggest that large microbial loads could be released via heavy precipitation events that produce runoff from livestock manure-applied agricultural fields, of even modest size, and could have a significant impact on water bodies within the watershed. Because of the lack of multiplication in the environment, highly elevated concentrations in manured land runoff, and correlation to protozoan parasite presence, Clostridium may be an alternative indicator for livestock manure contamination.