Armando S. Tasistro

Ammonia emissions from broiler litter: response to bedding materials and acidifiers

1. In a pen study, NH3 flux estimates were performed when clean wheat straw or wood shavings were used as bedding materials in combination with two NH3 control amendments: sodium bisulphate and a commercial premix of phosphoric + hydrochloric + citric acids. 2. Ammonia emissions from wood shavings were 19% greater than from wheat straw around waterers, but statistically similar around feeders. These results could be due to the greater caking observed when wheat straw was used. 3. Sodium bisulphate reduced NH3 emissions significantly only in the first half of the rearing period; the loss of efficacy in the second half resulted in total NH3 volatilisation not statistically different from the untreated control. The treatment containing phosphoric + hydrochloric + citric acids did not have a significant effect in decreasing NH3 emissions. 4. Bird mortality was not affected by the treatments, but broiler weight gain when wheat straw was used was significantly lower than with wood shavings, which could have been caused by the greater caking observed with wheat straw.

Water soluble phosphorus released by poultry litter: effect of extraction and time after application

The normally alkaline pH of poultry litter limits the solubility of P forms, especially the inorganic ones. Poultry litter acidification after field applications could result in increased P solubilization, so the use of water-soluble P (WSP) concentrations measured at the original litter pH might lead to an underestimation of the risk of P contamination of runoff water. In the laboratory, we studied the influence of pH (original and target pH 6 and 7) and shaking time (0.5, 1.0, 2.0, and 4.0 h) on the amounts of Total Dissolved P (TDP) and Molybdate Reactive P (MRP) extracted from two broiler and one breeder litters. Additionally we measured pH, MRP, and TDP evolution in the thatch and top 1 cm of soil during 115 days after application of broiler litter to a Bermudagrass pasture. Acidification of litter suspensions increased TDP by 34 to 72% and MRP by 24 to 69%. In the field, broiler litter pH decreased from 8.1 to 6.7 within 30 days after the application. The following evidence suggests that the WSP measured at the original litter pH might have been considerably less than that released in the field: (a) Based on adsorption isotherm data, the 97 μg P g–1 of soil applied as MRP would have been insufficient to result in an increased concentration of 16 μg P g–1 of soil as MRP; (b) The total increase in Dissolved Unreactive P (DUP) observed in soil (38 μg cm–2) was twice the amount measured in the litter at the original pH; and (c) The increase in MRP measured in soil 59 days after litter application could be linked to additional amounts of DUP not accounted for in the analysis at the original pH. These results highlight the importance of measuring WSP under conditions similar to those encountered by the litter after application.

Near-Infrared Reflectance Spectroscopy for the Analysis of Water and Total Nitrogen Contents in Poultry Litter

Near-Infrared Reflectance Spectroscopy (NIRS) offers advantages over gravimetric water content and dry combustion nitrogen determinations that could be significant for routine laboratory operations. Water content in ground and blended poultry litter samples was successfully estimated by NIRS, but total nitrogen predictions differed significantly from measured ones. The failure to predict total nitrogen could be related to the unspecific nature of the relation and to the quality of the data used for calibration. Additionally, a model was established that permits the estimation of water content in poultry litter in its original state from that measured after grinding and blending.

Composition of Aqueous Extracts of Broiler Litter Treated with Aluminum Sulfate, Ferrous Sulfate, Ferric Chloride and Gypsum

More knowledge on the composition of aqueous extracts of broiler litter amended for Water Soluble P (WSP) reduction would help to understand how amendments work. We measured pH, concentrations of Ca, Mg, Fe, Al, Cu, Mn, Zn, Molybdate Reactive P (MRP), and Dissolved Unreactive P (DUP) in water extracts of broiler litter treated with aluminum sulfate (ALS), ferrous sulfate (FES), ferric chloride (FEC), and gypsum (GYP) at 0, 5, 15, and 25% w/w. In order to study the effects of acidification, the same properties were measured in aqueous extracts of broiler litter suspensions that were titrated to end-points 3, 4, or 6 with 0.5N HCl. Concentrations of MRP, DUP, Ca and Mg, were 61%, 53%, 3.8 times, and 2.6 times greater in extracts from suspensions acidified to pH 6 than at the original pH of 8.9. ALS, FES, and FEC reduced pH, and showed similar effects on WSP concentrations, which were greater than with GYP. The magnitude of the reductions in WSP by ALS, FES, and FEC is uncertain because the actual amount of WSP immobilized cannot be determined. This is because of two opposite effects: 1) Through adsorption, soluble aluminum and iron remove phosphates from solution, and 2) Through acidification, iron and aluminum compounds release phosphates to solution.

Soluble Phosphorus Released by Poultry Wastes in Acidified Aqueous Extracts

Abstract Research has shown that measured water‐soluble phosphorus (WSP) from poultry litter might have been less than that released in the field. The effects of acidified extractions on soluble P (SP) concentrations were studied, and a buffer was selected to measure SP at pH 6.0, which is a target value for soil management in Georgia. Soluble P concentrations were extracted from poultry wastes at three pHs: 1) at natural pH, using deionized water (DIw); 2) after titrating DIw suspensions with 0.5N hydrochloric acid (HCl) to pH end‐points 3.0, 4.0, and 6.0; and 3) at pH 6.0 with buffers of sodium (Na) acetate, potassium hydrogen phthalate (KHP), 2‐(N‐morpholino) ethanesulphonic acid (MES), Na cacodylate, imidazole, N‐(2‐acetamido)‐2‐aminoethansulphonic acid (ACES), N‐(carbamoyl‐methyl) iminodiacetic acid (ADA), bis‐(2‐hydroxyethyl) imino]‐tris‐[(hydroxymethyl) methane (Bistris), and 1,4 piperazine‐bis‐(ethane sulphonic acid) (PIPES). Total SP increased 60% to 140% in suspensions acidified with HCl to pH 6.0 compared to suspensions at pH≥8. Dissolved unreactive P responded more (2× to 30×) than molybdate reactive P (20–100%). Buffers extracted more soluble minerals than suspensions acidified with HCl, probably because of their complexation ability. The most effective buffer was MES, because its effects seemed mainly due to acidification.

Effects of Storage by Freezing on Concentrations of Molybdate Reactive Phosphorus in Poultry Litter Extracts

Abstract In the laboratory, excessive variability in molybdate reactive phosphorus (MRP) concentrations in water extracts of poultry litter that appeared to be associated with storage by freezing was frequently observed. In one experiment, repeated twice, the effects of a factorial combination of storage temperatures [freezing (−16 to −15°C) or room temperature (21–24°C)] was studied for 60–62 h with poultry litter type (three broiler and one pullet) on MRP concentrations in water extracts. An additional experiment was conducted to compare the effects on phosphorus (P) concentration of a 1 mg P L−1 standard of spiking with 1 mg L−1 of Fe+3 or Al+3 and storage under room temperature or freezing for two and five days. No statistical differences were observed in MRP levels of extracts kept at room temperature measured immediately after the extraction, after 62 h or eight days. Freezing, however, consistently decreased MRP concentrations measured immediately after thawing compared to measurements in extracts kept at room temperature. Reductions ranged from less than 1% to 46%, depending on poultry litter composition, especially total iron (Fe) and aluminum (Al) concentrations. Freezing effects were reversible and after five days MRP concentrations were comparable to those of extracts kept always at room temperature. Spiking with Al+3 did not affect P solubility but spiking with Fe+3 and freezing for five days reduced the MRP concentrations in the P standard when measured immediately or two days after thawing. The results from the P, Fe+3, and Al+3 experiment plus the observation of precipitates containing P and Fe in some of the poultry litter extracts suggested complexing between these elements as a partial explanation of these responses. Organic compounds and Al+3 might also be involved. The solubilization of the floccules upon thawing might be retarded by changes induced by freezing. In consequence, freezing of water extracts of poultry litter can bring about significant, albeit transient, decreases in soluble orthophosphate concentrations.

Dynamics of water soluble phosphorus from surface applied broiler litter

Deionized water is routinely used as an extractant to determine soluble phosphorus (P) in broiler litter, but under N.E. Georgia conditions this technique may underestimate the hazard of P loss in runoff because the alkalinity of the broiler litter-water suspension limits the solubility of P compounds that may be solubilized after being spread on acidic field conditions. In this study under controlled conditions we measured soluble P in thatch and top soil after applying untreated broiler litter, residue of broiler litter after water extraction (WER), or residue of broiler litter after extraction with a 2-(N-morpholino) ethanesulfonic acid (MES) buffer at pH 6 (BER). During the 60 d incubation, the WER released 18 % more Total Dissolved P (TDP) than was determined through a conventional water extraction procedure, whereas the BER released 28 % less TDP than the WER, which reflects the greater amount of TDP removed from the broiler litter by the buffer at pH 6.0. However, the total amount of TDP extracted by the MES buffer, which includes that removed at the initial extraction plus that released during the incubation, was 30 % greater than the total amount of TDP extracted with water from the untreated litter plus the TDP extracted with water from the WER during the incubation. This result suggests the need to fine-tune the solid: liquid ratio and shaking time when the MES buffer is used.