Alum treatment of poultry litter: decomposition and nitrogen dynamics.

While the poultry industry is a major economic benefit to several areas in the USA, land application of poultry litter to recycle nutrients can lead to impaired surface and ground water quality. Amending poultry litter with alum [Al3(SO4)2 x 14H2O] has received considerable attention as a method of economically reducing ammonia volatilization in the poultry house and soluble phosphorus in runoff waters. The objective of this study was to characterize the effect of alum on broiler litter decomposition and N dynamics under laboratory conditions. Litter that had been amended with alum in the poultry house after each of the first four of five flock cycles (Experiment I) and litter that had been amended with alum after removal from a poultry house after the third flock cycle (Experiment II) were compared with unamended litter in separate studies. The litters in Experiment I were surface-applied to simulate application to grasslands, while the litters in Experiment II were incorporated to simulate application to conventionally tilled crops. The only statistically significant differences in decomposition due to alum occurred early in Experiment II and the differences were small. The only statistically significant differences in net N mineralization, soil inorganic N, and soil NH4+-N in either experiment was found in Experiment I after 70 d of incubation where soil inorganic N was significantly greater for the alum treatment. Thus, alum had little effect on decomposition or N dynamics. Results of many of the studies on litter not amended with alum should be applicable to litters amended with alum to reduce P availability.

Effects of amino acid dialysis solution on the nutrition of continuous ambulatory peritoneal dialysis patients.

OBJECTIVE: To evaluate the influence of 1.1% amino acid dialysis solution (AADS) on parameters of nutrition in continuous ambulatory peritoneal dialysis (CAPD) patients. STUDY DESIGN: Studies were performed in 8 men, using AADS for the overnight exchange. Before starting AADS, food intake, nutritional status, and laboratory indices were evaluated and compared to the respective parameters obtained after 3 and 6 months of treatment with AADS, as well as after 3 months of AADS withdrawal. With the start of AADS, doses of antacids were increased and modified during AADS administration; the modified doses were continued through 3 months after cessation of AADS. Another group of CAPD patients using standard dialysis solutions served as controls. In these patients the same parameters were evaluated four times at 3-month intervals. RESULTS: Administration of AADS resulted in: (1) 91% absorption of amino acids and improvement of serum amino acid pattern; (2) no change in nutritional intake during the treatment, but after the 3 months of AADS therapy, levels of nutrient intake were lower than those 3 months after withdrawal of AADS with correction of metabolic acidosis; (3) no change in indices of nutritional status, but 3 months after AADS discontinuation, total body weight, lean body mass, and body mass index were significantly higher than those shown after 3 months of treatment; (4) an increase in hemoglobin concentration, hematocrit, BUN, and blood H+. The examined parameters were not significantly changed in patients treated for 9 months with standard dialysis solutions exclusively. The values of nitrogen balance obtained during AADS administration and after 3 months of AADS withdrawal were significantly higher than those obtained in the respective periods in the control group. The blood pH, pCO2, and HCO3- in the last period of the study were higher in the AADS group than in the control group. CONCLUSION: In relatively well-nourished CAPD patients, overnight AADS administration results in increased serum concentration of amino acids without changes in other nutritional parameters. The use of AADS should be associated with increased doses of antacid medication, which abolishes the metabolic effects of acidosis that develop during AADS administration and facilitates positive nitrogen balance.