Effects of an Aluminum Sulfate and Ferric Chloride Blend on Poultry Litter Characteristics in Vitro

Effects of an Aluminum Sulfate and Ferric Chloride Blend on Poultry Litter Characteristics in Vitro Abstract Previous studies have applied various concentrations of aluminum sulfate and ferric chloride separately to poultry litter to reduce environmental pollution and increase chicken productivity. In the present study, we investigated the effect of using a blend of these 2 chemicals under 5 different treatments: control (no addition), 50 + 50, 25 + 50, 50 + 25, and 25 + 25 g/kg of litter, which consisted of fresh chicken manure (1 kg) and sawdust (4 kg) thoroughly mixed in a 70 × 47 × 43 cm box. NH3 and CO2 volatilizations, pH, electrical conductivity (EC) and moisture content of the poultry litter were assessed weekly up to 6 wk and in the case of total and water-soluble nutrients they were assessed after 1 and 42 d. The control treatment had higher NH3 and CO2 volatilizations than the treated litter throughout the experiment. EC and pH showed an inverse relationship, whereby the control treatment had high pH and low EC values and the treated litter had low pH and high EC values. After 42 d, nitrogen levels were significantly reduced in the control treatment, whereas the 50 + 50 g/kg treatment had the highest content. Conversely, water-soluble phosphorus levels were much lower in the treated poultry litter after 1 and 42 d. A higher ferric chloride concentration (25 + 50 g/kg) in the blend was more effective than a higher aluminum sulfate concentration (50 + 25 g/kg). These findings demonstrate that a combination of aluminum sulfate and ferric chloride may be a useful amendment for reducing NH3 and CO2 volatilizations, pH, and moisture content of poultry litter, which will help in improving poultry productivity, pollution control, and poultry litter fertilizer usage. DESCRIPTION OF PROBLEM Control of pollution arising from many different sources is a big challenge globally. The poultry industry is one growing source of pollution due to production of harmful gases, such as NH3, CO2, CH4, and N2O, which not only affect the environment but also have a direct impact on chicken health and productivity. Poultry litter is a mixture of bedding material, excreta, and waste feed generated during poultry production and is the main cause of the production of these various gases [1]. Among these gases, NH3 is the most important from an environmental and health perspective and therefore, its volatilizations need to be mitigated. NH3 gas volatilization above 25 ppm in a poultry house is harmful for chickens, reducing their performance [2–4]. Both the concentration and exposure time of birds to ammonia may effect health of birds and workers, such as tracheal irritation, eye damage, decreased feed efficiency and mortality [5]. The removal of gaseous ammonia from poultry litter can benefit bird health and productivity and reduce environmental concerns of emissions from poultry production [6]. Furthermore, manure storage sites also act as a source of NH3. Therefore, as the poultry industry expands, there is increasing concern about the release of such gases. Countries that are more dependent on agriculture and the livestock industry will face an increasing issue with pollution unless its sources are addressed [7]. In the United States, more than 80% of NH3 arises from agricultural sources [7], and France and Germany produce more NH3 gas than any other European country [8]. It is estimated that 26.7% of NH3 volatilizations arise from poultry production, which is second only to cattle farming [7]. To increase bird performance, NH3 volatilization needs to be reduced. Microbial breakdown of wastes of birds results in the formation of NH3 as bird manure is rich in nitrogen [9]. The level of volatilizations from this manure depends on the conditions, with a pH > 7, high moisture levels, and warm temperatures being required for the production of NH3 gas, leading to seasonal variation in NH3 volatilizations [9]. Factors which cause NH3 generation include physical and chemical litter properties (temperature, moisture, pH, and N content), type of original bedding material, and spatial characteristics of gas evolution within houses [10]. In addition, CO2 and CH4 volatilization need to be considered because they affect chicken performance and weight. For example, exposure of chickens to 12,000 ppm of CO2 decreases body weight by approximately 60 g at 4 wk of age, and this persists until 7 wk of age [2]. For CO2, the maximum 8-h exposure limit is 5,000 ppm and the maximum 15-min exposure limit is 30,000 ppm [11]. CO2 concentrations from the poultry industry can be reduced in 2 ways. First, because CO2 and NH3 mainly arise from the breakdown of uric acid by bacteria, treatments reduce microbial activity by lowering pH. Second, CO2 concentrations can be reduced using less fuel for heating and ventilation in the poultry house [12]. Because of the high demand for chicken products, many methods have been used in the past to control the concentration of these gases in poultry houses and improve the health of chickens, including improving the ventilation system, controlling nutrients in the diet, and adding chemicals to poultry manure (litter amendment). However, some of these are very expensive, and therefore, more cost-effective methods are required to increase chicken productivity. Poultry litter is considered to be the best source of organic material and can be used as a fertilizer [13]. Poultry manure is not only beneficial for crop production because of its high nutrient content but also improves the structural stability of the soil [14]. Poultry litter can be applied fresh or after composting [13], although fresh litter may contain an imbalance of nutrients. The most important nutrients for increasing soil fertility are nitrogen, phosphorus, and potassium (NPK). N and P are of primary environmental importance for poultry broiler production [15]. Many compounds are available to reduce NH3. Aluminum sulfate is unique chemical for litter amendment as it not only reduces NH3 volatilizations but also reduces P solubility and N loss [16–19]. Additional chemicals that are used commercially as litter treatments include ferric chloride, ferric sulfate and sodium bisulfate. These amendments act by either inhibiting microbial transformation of urea or uric acid into NH3 or by acidification and subsequent conversion of volatile NH3 to non-volatile ammonium (NH4+) [6]. Some of these chemicals are widely used by farmers, whereas others have a more limited application because their high costs prohibit them from being used at a large scale. Moreover, people are generally reluctant to use these chemicals because direct exposure to some of them can cause health issues. Aluminum sulfate and ferric chloride both should be handled with care because skin irritation can result from contact [20]. However, the effectiveness of blending 2 chemicals has not yet been fully realized. Therefore, the objective of this study was to evaluate the effectiveness of using a blend of aluminum sulfate and ferric chloride to alter poultry litter characteristics under laboratory condition, i.e., NH3 and CO2 volatilizations, pH, electrical conductivity (EC), moisture content, and total and water-soluble nutrient contents. MATERIALS AND METHODS Experimental Design This study was conducted at Gyeongsang National University, South Korea. The poultry litter used in the experiment was a mixture of fresh chicken manure and sawdust, which had moisture contents of 77% and 24%, respectively. In total, 1 kg of manure and 4 kg of sawdust were mixed thoroughly and placed to a depth of 9 cm in plastic rectangular boxes (70 × 47 × 43 cm) that had 2 8-cm-diameter holes on opposite sides for inlet and outlet of air (Figure 1). These boxes were kept in a room that was maintained at a temperature of approximately 25°C throughout the experiment. After mixing manure and sawdust the gases volatilization varies quickly and there were much difference in all boxes in first few d. To minimize the difference the litter was left in the boxes for 1 wk before treatment, which consisted of a blend of aluminum sulfate [Al2(SO4)3 ⋅ 14H2O] and ferric chloride (FeCl3). To determine effective ratio of blending 2 chemicals for management of poultry litter 5 different treatments were used with 3 replicates per treatment: control (no chemicals), T1 (50 + 50 g/kg), T2 (25 + 50 g/kg), T3 (50 + 25 g/kg), and T4 (25 + 25 g/kg), where the concentrations represent aluminum sulfate + ferric chloride gram per kilogram of litter. Figure 1. View largeDownload slide Schematic diagram of boxes for storage of poultry litter. Figure 1. View largeDownload slide Schematic diagram of boxes for storage of poultry litter. Because this was a laboratory experiment, the chickens were not reared on litter, and therefore, the proportion of manure in the sawdust was lower than that in normal poultry litter. In poultry houses, continuous addition of water and manure results in the chemicals being covered with manure, which increases the alkalinity and pH more readily. Litter Sampling Prior to adding the aluminum sulfate/ferric chloride blends, NH3 and CO2 volatilizations above the poultry litter were assessed. Samples were taken at 5 random depths between the top and bottom of the litter and mixed together, with 3 replicates per treatment. Three subsamples were then taken to assess pH, EC, and moisture content. Each of these parameters was then reassessed 2 h after applying the blends, and additional litter samples were analyzed on a weekly basis for 6 wk. EC, pH, and Moisture Content EC and pH of the litter samples were determined by adding 100 mL of distilled water to 10 g of litter in a beaker and mixing thoroughly for 5 min [21]. The litter slurry was then allowed to settle for 10 min. EC and pH were measured using a digital EC and pH meter [22]. The moisture content of the litter was determined by taking 3 samples with an initial wet weight of 10 g from each treatment. These samples were dried in an oven for 24 h at 105°C and then reweighed to calculate the moisture content [22]. NH3 and CO2 Volatilization Measurements Atmospheric NH3 was determined 10 cm above the litter in each box using 2 methods: Gastec ammonia tubes [23] and an electrochemical sensor (“ZDL800” ammonia meter) [24]. Gastec ammonia tubes with a range of 0.5–70 ppm were used to check NH3 volatilizations at the center of each box on a weekly basis. In addition, the ZDL800 ammonia meter was used in parallel to check the accuracy of these readings. Because the exposure of an electrochemical sensor to high concentrations of NH3 over long periods leads to error in the readings, the ZDL800 sensor was used for 1 h every 3 d to check each box, and data were transferred to PC. This sensor is equipped to store the date, time, number of exposure points, interval between each point, and actual exposure points. Average weekly data from the ZDL800 ammonia meter were used for analysis. The % reduction in NH3 was calculated by the following equation:   \begin{eqnarray*} &&{{\rm{N}}{{\rm{H}}_3}\% \,{\rm{reduction}}}\nonumber\\ &&\quad = \frac{{{\rm{N}}{{\rm{H}}_3}({\rm{initial}}) - {\rm{N}}{{\rm{H}}_3}({\rm{final}})}}{{{\rm{N}}{{\rm{H}}_3}({\rm{initial}})}} \times 100 \end{eqnarray*} CO2 was measured by placing a “Lutron MCH-383SD” electrochemical sensor [25] in each box. Lutron MCH-383SD is equipped to record the date, time interval, and number of exposure points and has a memory card to store these data. CO2 was checked at 10-min intervals over 24 h on every 3 d, and weekly recorded data were averaged for further analysis and interpretation. The % reduction in CO2 was calculated by the following equation:   \begin{eqnarray*} &&{{\rm{C}}{{\rm{O}}_2}\% \,{\rm{reduction}}}\nonumber\\ &&\quad = \frac{{{\rm{C}}{{\rm{O}}_2}({\rm{initial}}) - {\rm{C}}{{\rm{O}}_2}({\rm{final}})}}{{{\rm{C}}{{\rm{O}}_2}({\rm{initial}})}} \times 100 \end{eqnarray*} The volatilization reduction rate (%) was calculated by the following equation   \begin{eqnarray*} &&{{\rm{Volatilization}}\,{\rm{Reduction}}\,{\rm{rate}}\left( {\rm{\% }} \right)}\nonumber\\ &&\quad = \frac{{{\rm{CV}}\,\left( {{\rm{control}}} \right)\, - \,{\rm{CV}}\,\left( {{\rm{Treatment}}} \right)}}{{{\rm{CV}}\left( {{\rm{Control}}} \right)}} \times 100 \end{eqnarray*} CV: Cumulative Volatilization Nutrient Analysis The total C, N, P, K, Fe and Al contents of the litter were measured 1 and 42 d after applying the blends. as were the concentrations of water-soluble P, Fe, and Al using 20-g subsamples. The total C and N percentages were determined by the dry combustion method using a Model 2000 LECO (St. Joseph, MI) CNS analyzer [26]. Moist samples were used for this analysis because oven drying results in N losses [12]. Total P, K, Fe and Al contents were determined by oven drying the litter at 60°C, digesting it with HNO3 [27], and analyzing the digested samples using inductively coupled plasma (ICP) emission spectrometry [28]. Water-soluble P, Al, and Fe contents were measured by shaking the wet litter with deionized water (1:10 litter to water ratio) for 2 h, followed by centrifugation and filtration through 0.45-μm Millipore (Bedford, MA) filter paper [29]. Each element concentration in the filtrate was then determined by ICP emission spectrometry [28]. Statistical Analysis Statistical analysis was performed using the Prism 5 Graph Pad program [30]. Data were presented as means ± SEM and analyzed by one-way ANOVA followed by Bonferroni's Multiple Comparison Test with a significance level of P < 0.05. RESULTS AND DISCUSSION NH3 and CO2 Volatilizations The initial volatilizations of NH3 in the Control, T1, T2, T3, and T4 were 80, 84, 86, 83, and 81 ppm, respectively. Because no further manure or water was added during this experiment, atmospheric NH3 in the untreated litter (control) decreased to 60, 35, 25, 17, 16, and 14 ppm at wk 1, 2, 3, 4, 5, and 6, respectively, representing an 83.7% reduction after 6 wk (Figure 2). Conversely, in T1, the NH3 volatilization was 0, 0.1, 0.4, 1.13, 3.25, and 4.9 ppm at wk 1, 2, 3, 4, 5, and 6, respectively, representing a 94.3% reduction after 6 wk compared with the initial level. In T2, the NH3 volatilization was 0, 0.1, 0.35, 1.4. 3.75, and 5.1 ppm at wk 1, 2, 3, 4, 5, and 6, respectively, representing a 94% reduction after 6 wk. In T3, the NH3 volatilization was 0, 0.2, 0.75, 2.7, 4.75, and 6.2 ppm at wk 1, 2, 3, 4, 5, and 6, respectively, representing a 92.5% reduction after 6 wk. In T4, the NH3 volatilization was 0, 0.2, 0.85, 3.1, 5.4, and 7.3 ppm at wk 1, 2, 3, 4, 5, and 6, respectively, representing a 90.9% reduction after 6 wk. The cumulative NH3 volatilization reduction rates relative to the control treatment are presented in Table 1. Figure 2. View largeDownload slide Ammonia and carbon dioxide volatilization (means ± SEM) from poultry litter with various concentration of blends. Control (no treatment); T1: 50 + 50 g/kg; T2: 25 + 50 g/kg; T3: 50 + 25 g/kg; and T4: 25 + 25 g/kg (expressed as aluminum sulfate + ferric chloride per kilogram of litter). Figure 2. View largeDownload slide Ammonia and carbon dioxide volatilization (means ± SEM) from poultry litter with various concentration of blends. Control (no treatment); T1: 50 + 50 g/kg; T2: 25 + 50 g/kg; T3: 50 + 25 g/kg; and T4: 25 + 25 g/kg (expressed as aluminum sulfate + ferric chloride per kilogram of litter). Table 1. NH3 and CO2 volatilization reduction rates (%) from poultry litter over 6 wk following the addition of various aluminum sulfate/ferric chloride blends. Values are relative to the control treatment.   VR% NH3  VR% CO2  Treatments  Week  1  2  3  4  5  6  Week  1  2  3  4  5  6  T11    100a ± 0  99.7a ± 0.02  98.4a,b ± 0.08  93.3c ± 0.08  79.6d ± 0.11  65.1e ± 0.46    24.1a ± 0.23  24.5a ± 0.2  21.1b ± 0.23  46.5c ± 0.2  44.5d ± 0.21  44.3d ± 0.17  T21    100a ± 0  99.7a ± 0.05  98.6a,b ± 0.04  93.2c ± 0.07  76.5d ± 0.04  63.5e ± 0.15    20.9a ± 0.23  24.5b ± 0.11  17c ± 0.26  41.2d ± 0.18  42.4d,e ± 0.04  38.4f ± 0.02  T31    100a ± 0  99.4a ± 05  97b ± 0.23  84.1c ± 0.1  70.3d ± 0.1  55.7e ± 0.06    14.6a ± 0.12  27.8b ± 0.18  12c ± 0.31  40.3d ± 0.14  34.5e ± 0.2  28.1b ± 0.11  T41    100a ± 0  99.4a ± 0.03  97b ± 0.04  84.1c ± 0.02  70.3d ± 0.14  55.7e ± 0.06    18.3a ± 0.11  23.8b ± 0.04  7.5c ± 0.13  30.8d ± 0.07  32.6e ± 0.05  29.3f ± 0.04    VR% NH3  VR% CO2  Treatments  Week  1  2  3  4  5  6  Week  1  2  3  4  5  6  T11    100a ± 0  99.7a ± 0.02  98.4a,b ± 0.08  93.3c ± 0.08  79.6d ± 0.11  65.1e ± 0.46    24.1a ± 0.23  24.5a ± 0.2  21.1b ± 0.23  46.5c ± 0.2  44.5d ± 0.21  44.3d ± 0.17  T21    100a ± 0  99.7a ± 0.05  98.6a,b ± 0.04  93.2c ± 0.07  76.5d ± 0.04  63.5e ± 0.15    20.9a ± 0.23  24.5b ± 0.11  17c ± 0.26  41.2d ± 0.18  42.4d,e ± 0.04  38.4f ± 0.02  T31    100a ± 0  99.4a ± 05  97b ± 0.23  84.1c ± 0.1  70.3d ± 0.1  55.7e ± 0.06    14.6a ± 0.12  27.8b ± 0.18  12c ± 0.31  40.3d ± 0.14  34.5e ± 0.2  28.1b ± 0.11  T41    100a ± 0  99.4a ± 0.03  97b ± 0.04  84.1c ± 0.02  70.3d ± 0.14  55.7e ± 0.06    18.3a ± 0.11  23.8b ± 0.04  7.5c ± 0.13  30.8d ± 0.07  32.6e ± 0.05  29.3f ± 0.04  Notes: Percentage of concentration reduction on a weekly basis compared with the control treatment. $${\rm{Volatilization\ }}\,\,{\rm{Reduction}}\,\,{\rm{rate\ }}( {\rm{\% }} ) = \frac{{{\rm{CV\ }}( {{\rm{control}}} ){\rm{\ }} - {\rm{\ CV\ }}( {{\rm{Treatment}}} )}}{{{\rm{CV\ }}( {{\rm{Control}}} )}} \times 100$$ VR: Volatilization Reduction, CV: Cumulative Volatilization. a–eMeans in a row having different superscripts are significantly different (P < 0.05). 1Application of the chemical blend Al2(SO4)3 · 14H2O + FeCl3 at a concentration of 50 + 50 g/kg (T1), 25 + 50 g/kg (T2), 50 + 25 g/kg (T3), and 25 + 25 g/kg (T4). View Large CO2 volatilizations were reduced in all treatments. However, the addition of an aluminum sulfate/ferric chloride blend caused this reduction to occur more quickly. The initial CO2 volatilizations in the control, T1, T2, T3, and T4 were 1,188, 1,134, 1,093, 1,195, and 1,146 ppm, respectively. After applying the blends, the CO2 volatilization and temperature of the litter suddenly increased because of reaction of the chemicals and then reduced after 1 d. The average CO2 volatilizations at the end of the 6th wk were 679, 378, 418, 488, and 480 ppm in the control, T1, T2, T3 and T4, respectively, representing a 42.8%, 66.6%, 61.7%, 59.1%, and 58.1% reduction in each. The cumulative CO2 volatilization reduction rates relative to the control treatment are shown in Table 1. These findings demonstrate that the addition of an aluminum sulfate/ferric chloride blend to poultry litter dramatically reduces NH3 and CO2 volatilizations. Furthermore, the use of higher volatilizations of aluminum sulfate and ferric chloride led to greater reductions in NH3 than those with the use of lower volatilizations because the NH3 volatilization was nearly zero after the first 2 wk but then slowly began to be emitted in all treatments. NH3 volatilizations of T1 and T2 were nearly identical throughout the experiment (P > 0.05) and were lower than those of T3 and T4. Significant differences were observed between the control treatment and all of the blend treatments over 6 wk (P < 0.05), and at the end of the 6-wk period, there were also significant differences between T1 and T4 and between T2 and T4 (P < 0.05). Moore [19] previously showed that NH3 volatilizations were greatly reduced following the application of aluminum sulfate. Similarly, Choi reported that the application of aluminum sulfate led to an 87% reduction in NH3 after 42 d compared with the control treatment [31] and that the use of aluminum sulfate reduced NH3 volatilizations by 77%–96% [32]. Ferric chloride has also been shown to greatly reduce NH3 at a range of volatilizations. In the present study, it was found that a rate of 25 g/kg aluminum sulfate + 50 g/kg ferric chloride was more effective than 50 g/kg aluminum sulfate + 25 g/kg ferric chloride in reducing NH3 volatilizations and pH of the litter. The average NH3 volatilization reductions were 89.3%, 88.5%, 84.4%, and 81.9% for T1, T2, T3, and T4, respectively, as shown in Figure 3. Figure 3. View largeDownload slide Comparison of ammonia and carbon dioxide volatilization reduction (VR) % between treated litters of 6 wk. T1: 50 + 50 g/kg; T2: 25 + 50 g/kg; T3: 50 + 25 g/kg; and T4: 25 + 25 g/kg (expressed as aluminum sulfate + ferric chloride per kilogram of litter). Note: Percentage of VR presented on weekly basis compared with the control treatment and VR% are average data of 6 wk. $${\rm{Volatilization\ }}\,\,{\rm{Reduction}}\,\,{\rm{rate\ \ }}( {\rm{\% }} ) = \frac{{{\rm{CV\ }}( {{\rm{control}}} ){\rm{\ }} - {\rm{\ CV\ }}( {{\rm{Treatment}}} )}}{{{\rm{CV\ }}( {{\rm{Control}}} )}}{\rm{\ \ }} \times {\rm{\ }}100$$ CV: Cumulative Volatilization. In this case control treatment cannot be calculated by this formula. Figure 3. View largeDownload slide Comparison of ammonia and carbon dioxide volatilization reduction (VR) % between treated litters of 6 wk. T1: 50 + 50 g/kg; T2: 25 + 50 g/kg; T3: 50 + 25 g/kg; and T4: 25 + 25 g/kg (expressed as aluminum sulfate + ferric chloride per kilogram of litter). Note: Percentage of VR presented on weekly basis compared with the control treatment and VR% are average data of 6 wk. $${\rm{Volatilization\ }}\,\,{\rm{Reduction}}\,\,{\rm{rate\ \ }}( {\rm{\% }} ) = \frac{{{\rm{CV\ }}( {{\rm{control}}} ){\rm{\ }} - {\rm{\ CV\ }}( {{\rm{Treatment}}} )}}{{{\rm{CV\ }}( {{\rm{Control}}} )}}{\rm{\ \ }} \times {\rm{\ }}100$$ CV: Cumulative Volatilization. In this case control treatment cannot be calculated by this formula. The CO2 volatilization reduction rates relative to the control treatment over all 6 wk are shown in Table 1. The average CO2 volatilization reductions were 34.1%, 30.7%, 26.2%, and 23.7% for T1, T2, T3, and T4, respectively, as shown in Figure 3. Li [12] previously reported that CO2 volatilizations of a poultry house could be reduced by reducing the microbial activity or fuel consumption. In this study, the pH and moisture content of poultry litter were reduced by applying a blend that made the conditions unfavorable for microorganisms to survive, causing CO2 volatilizations to decrease over time. CO2 volatilizations were higher for the control treatment than for all other treatments because of the slight reduction in pH and slow rate of moisture content reduction, with all treatments except T3 and T4 showing a significant difference from the control treatment after 6 wk (P < 0.05). pH, EC, and Moisture Content Application of a blend of aluminum sulfate and ferric chloride at various concentrations had a significant effect on the pH, EC (mS/cm), and percent moisture content (MC) of the poultry litter. Before applying the blends, initial values of each of these were almost identical across treatments. Average values for pH, EC, and MC are presented in Table 2, illustrating how the blends affected these parameters during the 6-wk period. Table 2. Effects of various aluminum sulfate/ferric chloride blends on the pH, electrical conductivity (EC), and moisture content (MC) of poultry litter over 6 wk. Items  pH  EC(mS/cm)  MC%  Wk  C  T1  T2  T3  T4  C  T1  T2  T3  T4  C  T1  T2  T3  T4  1  8.04a ± 0.015  3.7b ± 0.005  3c ± 0.008  3.88d ± 0.008  4.06e ± 0.012  1.54a ± 0.01  9.76b ± 0.90  9.68b ± 0.31  7.42b,c ± 0.65  7.98b,c ± 0.47  35.2a ± 0.16  33.4b ± 0.3  33.8b ± 0.12  33.7b ± 0.13  33.8b ± 0.20  2  7.3a ± 0.012  3.72b,c ± 0.014  3.62c ± 0.014  4.03d ± 0.012  4.3e ± 0.008  1.63a ± 0.03  9.51b ± 0.15  9.14b ± 0.25  6.51c ± 0.05  6.41c ± 0.05  33.7a ± 0.03  31.8a,b ± 0.12  32.1a–c ± 0.17  32.2a–c ± 0.03  33a ± 0.31  3  7.25a ± 0.017  3.68b ± 0.017  3.58b,c ± 0.016  4.1d ± 0.005  4.29e ± 0.014  1.69a ± 0.01  8.74b ± 0.14  9.12b ± 0.18  7.01c ± 0.12  6.85c ± 0.34  30.9a ± 0.08  27b ± 0.16  28.6c ± 0.14  27.9c ± 0.13  29.3c ± 0.08  4  7.21a ± 0.015  3.81b ± 0.005  3.71c ± 0.017  4.05d ± 0.005  4.43e ± 0.003  1.76a ± 0.05  9.65b ± 0.34  9.41b ± 0.14  7.45c ± 0.12  6.75c ± 0.08  31.1a ± 0.42  25.6b ± 0.12  26.5b ± 0.26  25.9b ± 0.18  29.1c ± 0.53  5  7.15a ± 0.04  3.77b ± 0.015  3.7b ± 0.021  4.07c ± 0.005  4.5d ± 0.02  1.5a ± 0.02  8.75b ± 0.06  8.71b ± 0.03  8.16b,c ± 0.23  6.86c ± 0.19  28.7a ± 0.1  25b ± 0.12  26b ± 0.1  25.3b ± 0.14  27.5a ± 0.06  6  7.1a ± 0.008  3.79b ± 0.011  3.72b ± 0.003  4.09c ± 0.02  4.51d ± 0.02  1.68a ± 0.03  9.33b ± 0.3  9.4b ± 0.24  7.9c ± 0.01  7.66c ± 0.14  25.3a ± 0.05  20.9b ± 0.12  22.5b ± 0.05  21.8b ± 0.03  25.1a ± 003  Items  pH  EC(mS/cm)  MC%  Wk  C  T1  T2  T3  T4  C  T1  T2  T3  T4  C  T1  T2  T3  T4  1  8.04a ± 0.015  3.7b ± 0.005  3c ± 0.008  3.88d ± 0.008  4.06e ± 0.012  1.54a ± 0.01  9.76b ± 0.90  9.68b ± 0.31  7.42b,c ± 0.65  7.98b,c ± 0.47  35.2a ± 0.16  33.4b ± 0.3  33.8b ± 0.12  33.7b ± 0.13  33.8b ± 0.20  2  7.3a ± 0.012  3.72b,c ± 0.014  3.62c ± 0.014  4.03d ± 0.012  4.3e ± 0.008  1.63a ± 0.03  9.51b ± 0.15  9.14b ± 0.25  6.51c ± 0.05  6.41c ± 0.05  33.7a ± 0.03  31.8a,b ± 0.12  32.1a–c ± 0.17  32.2a–c ± 0.03  33a ± 0.31  3  7.25a ± 0.017  3.68b ± 0.017  3.58b,c ± 0.016  4.1d ± 0.005  4.29e ± 0.014  1.69a ± 0.01  8.74b ± 0.14  9.12b ± 0.18  7.01c ± 0.12  6.85c ± 0.34  30.9a ± 0.08  27b ± 0.16  28.6c ± 0.14  27.9c ± 0.13  29.3c ± 0.08  4  7.21a ± 0.015  3.81b ± 0.005  3.71c ± 0.017  4.05d ± 0.005  4.43e ± 0.003  1.76a ± 0.05  9.65b ± 0.34  9.41b ± 0.14  7.45c ± 0.12  6.75c ± 0.08  31.1a ± 0.42  25.6b ± 0.12  26.5b ± 0.26  25.9b ± 0.18  29.1c ± 0.53  5  7.15a ± 0.04  3.77b ± 0.015  3.7b ± 0.021  4.07c ± 0.005  4.5d ± 0.02  1.5a ± 0.02  8.75b ± 0.06  8.71b ± 0.03  8.16b,c ± 0.23  6.86c ± 0.19  28.7a ± 0.1  25b ± 0.12  26b ± 0.1  25.3b ± 0.14  27.5a ± 0.06  6  7.1a ± 0.008  3.79b ± 0.011  3.72b ± 0.003  4.09c ± 0.02  4.51d ± 0.02  1.68a ± 0.03  9.33b ± 0.3  9.4b ± 0.24  7.9c ± 0.01  7.66c ± 0.14  25.3a ± 0.05  20.9b ± 0.12  22.5b ± 0.05  21.8b ± 0.03  25.1a ± 003  Notes: The chemical blend Al2(SO4)3·14H2O + FeCl3 was applied. Control (no addition); T1: 50 + 50 g/kg; T2: 25 + 50 g/kg; T3: 50 + 25 g/kg; and T4: 25 + 25 g/kg (expressed as aluminum sulfate + ferric chloride per kilogram of litter). All values are expressed as means ± SEM. a–eMeans in a row having different superscripts are significantly different (P < 0.05). View Large In all treatments, the pH was dramatically reduced immediately after applying the blends and then showed an increasing trend up to 6 wk. The litter pH was significantly lower in all 4 blend treatments than that of the untreated control (P < 0.05; Table 2). Furthermore, these significant differences were observed for all 6 wk for all treatments, except T1 and T2, which were not significantly different in wk 5 and 6. The application of 50 g/kg ferric chloride with aluminum sulfate (T1 and T2) led to a greater decrease in pH than lower concentrations of ferric chloride (T3 and T4). Therefore, it appears that higher concentrations of ferric chloride in a blend are more effective in reducing the pH than higher concentrations of aluminum sulfate. EC showed an inverse relationship with pH. Application of the blends led to a reduction in the pH and a concurrent increase in EC. EC of the treated litter showed varying trends through time, but EC of the control treatment was much lower than that of the treated litter throughout the experiment. There were also significant differences in the EC values between all treatments (P < 0.05), with the exception of “T1 and T2” and “T3 and T4”, which were not significantly different over all 6 wk. The use of a higher blend concentration led to higher EC values than a lower blend concentration or no treatment (control), which is similar to the findings of Moore et al. [18], who also observed higher EC values with the application of a higher aluminum sulfate concentration. In a poultry house, the moisture content increases because of continuous addition of manure and water. However, in this experiment, the moisture content decreased by 31.6%, 43.6%, 40.6%, 41.7%, and 33.2% in the control, T1, T2, T3, and T4, respectively, after 6 wk. The use of chemicals can affect the moisture content of poultry litter. In this study, the moisture content of the control treatment litter was higher than that of the treated litter throughout the experiment, Also previous study found that chemical additives lowered the moisture content of the litter compared with the control treatment [33]. Relationship between pH and NH3 Figure 4 shows the direct positive relationship between pH and NH3 volatilizations, whereby the 2 increase or decrease simultaneously. The highest NH3 volatilizations and pH were observed in the control treatment, whereas the lowest were observed in T1. Our findings showed that manipulating the pH of the litter to ≤3.5 the NH3 volatilization becomes zero. The highest NH3 volatilization (77 ppm) and pH (8.01) were observed in the control treatment after 1 wk. Figure 4. View largeDownload slide Relationship between pH and ammonia volatilization with various concentration of blends during 6 wk. Control (no treatment); T1: 50 + 50 g/kg; T2: 25 + 50 g/kg; T3: 50 + 25 g/kg; and T4: 25 + 25 g/kg (expressed as aluminum sulfate + ferric chloride per kilogram of litter). Figure 4. View largeDownload slide Relationship between pH and ammonia volatilization with various concentration of blends during 6 wk. Control (no treatment); T1: 50 + 50 g/kg; T2: 25 + 50 g/kg; T3: 50 + 25 g/kg; and T4: 25 + 25 g/kg (expressed as aluminum sulfate + ferric chloride per kilogram of litter). Nutrient Analysis There were significant differences in some of the total and water-soluble nutrient contents between the treated and control litter after 1 and 42 d of applying the blends. In general, application of the blends led to good results, as summarized in Table 3. It was also found that nutrient concentrations in the litter varied through time. Also, the Madrid study revealed that evolution of nutrients content were dependent on time and litter treatment [34]. Table 3. Nutrients content comparison of poultry litter that was untreated (control) or treated with various aluminum sulfate/ferric chloride blends after 1 and 42 d. Nutrients  After 1 d  After 42 d  g/kg  Control  T1  T2  T3  T4  Control  T1  T2  T3  T4  Total C  270a ± 3.16  257a ± 0.83  258a ± 3.05  258.2a ± 2.03  263.2a ± 4.93  351a ± 1.20  323a ± 16.2  321a ± 2.89  315a ± 6.49  326a ± 5.53  Total N  4.97a ± 0.40  5.02a ± 0.14  5.05a ± 0.15  5.17a ± 0.62  5.84a ± 0.47  2.35a ± 0.16  6.36b ± 0.74  6.43b ± 0.94  6.13b ± 1.39  6.34b ± 0.32  Total P  1.93a ± 0.04  1.57b ± 0.06  1.777a ± 0.03  1.632b,c ± 0.02  1.657b,c ± 0.04  0.954a ± 0.02  0.72a,b ± 0.01  0.775a ± 0.007  0.838a,c ± 0.01  0.803a ± 0.01  Total K  3.097a ± 0.11  2.913a ± 0.06  3.05a ± 0.1  2.908a ± 0.04  2.94a ± 0.09  1.97a ± 0.04  1.497b ± 0.05  1.63b ± 0.04  1.685b,c ± 0.03  1.788a–c ± 0.01  Total Al  0.563a ± 0.04  5.302b ± 0.12  3.662c ± 0.07  5.232b ± 0.08  3.347c ± 0.006  0.183a ± 0.01  2.723b ± 0.04  1.926c ± 0.04  3.359d ± 0.04  2.18e ± 0.03  Total Fe  1.038a ± 0.13  20.565b ± 0.42  22.81c ± 0.38  13.183d ± 0.22  12.842d ± 0.20  0.507a ± 0.02  9.103b ± 0.14  10.231c ± 0.20  6.901d ± 0.1  7.532d ± 0.17  WS-P  1.158a ± 0.01  0.081b ± 0.004  0.078b ± 0.005  0.083b ± 0.003  0.08b ± 0.015  0.891a ± 0.05  0.094b ± 0.004  0.087b ± 0.006  0.106b ± 0.008  0.111b ± 0.007  WS-Fe  0.062a ± 0.01  2.855b ± 0.15  2.813b ± 0.02  1.535d ± 0.03  1.417d ± 0.21  0.077a ± 0.007  1.823b ± 0.06  1.869b ± 0.04  0.565c ± 0.008  0.52c ± 0.005  WS1-Al  0.071a ± 0.001  3.629b ± 0.06  1.533a ± 0.28  2.955b ± 0.62  1.425a ± 0.30  0.023a ± 0.009  2.002b ± 0.17  1.1c ± 0.03  1.508b,c ± 0.12  0.997b ± 0.06  Nutrients  After 1 d  After 42 d  g/kg  Control  T1  T2  T3  T4  Control  T1  T2  T3  T4  Total C  270a ± 3.16  257a ± 0.83  258a ± 3.05  258.2a ± 2.03  263.2a ± 4.93  351a ± 1.20  323a ± 16.2  321a ± 2.89  315a ± 6.49  326a ± 5.53  Total N  4.97a ± 0.40  5.02a ± 0.14  5.05a ± 0.15  5.17a ± 0.62  5.84a ± 0.47  2.35a ± 0.16  6.36b ± 0.74  6.43b ± 0.94  6.13b ± 1.39  6.34b ± 0.32  Total P  1.93a ± 0.04  1.57b ± 0.06  1.777a ± 0.03  1.632b,c ± 0.02  1.657b,c ± 0.04  0.954a ± 0.02  0.72a,b ± 0.01  0.775a ± 0.007  0.838a,c ± 0.01  0.803a ± 0.01  Total K  3.097a ± 0.11  2.913a ± 0.06  3.05a ± 0.1  2.908a ± 0.04  2.94a ± 0.09  1.97a ± 0.04  1.497b ± 0.05  1.63b ± 0.04  1.685b,c ± 0.03  1.788a–c ± 0.01  Total Al  0.563a ± 0.04  5.302b ± 0.12  3.662c ± 0.07  5.232b ± 0.08  3.347c ± 0.006  0.183a ± 0.01  2.723b ± 0.04  1.926c ± 0.04  3.359d ± 0.04  2.18e ± 0.03  Total Fe  1.038a ± 0.13  20.565b ± 0.42  22.81c ± 0.38  13.183d ± 0.22  12.842d ± 0.20  0.507a ± 0.02  9.103b ± 0.14  10.231c ± 0.20  6.901d ± 0.1  7.532d ± 0.17  WS-P  1.158a ± 0.01  0.081b ± 0.004  0.078b ± 0.005  0.083b ± 0.003  0.08b ± 0.015  0.891a ± 0.05  0.094b ± 0.004  0.087b ± 0.006  0.106b ± 0.008  0.111b ± 0.007  WS-Fe  0.062a ± 0.01  2.855b ± 0.15  2.813b ± 0.02  1.535d ± 0.03  1.417d ± 0.21  0.077a ± 0.007  1.823b ± 0.06  1.869b ± 0.04  0.565c ± 0.008  0.52c ± 0.005  WS1-Al  0.071a ± 0.001  3.629b ± 0.06  1.533a ± 0.28  2.955b ± 0.62  1.425a ± 0.30  0.023a ± 0.009  2.002b ± 0.17  1.1c ± 0.03  1.508b,c ± 0.12  0.997b ± 0.06  Notes: Control (no addition); T1: 50 + 50 g/kg; T2: 25 + 50 g/kg; T3: 50 + 25 g/kg; and T4: 25 + 25 g/kg (expressed as aluminum sulfate + ferric chloride per kilogram of litter). CN and WS results are expressed on a wet weight basis, while all other values are expressed on a dry weight basis. All values are expressed as means ± SEM. a–eMeans in a row having different superscripts are significantly different (P < 0.05). 1WS: water-soluble nutrients. View Large N contents in the control, T1, T2, T3, and T4 were 4.97, 5.02, 5.05, 5.17, and 5.84 g/kg, respectively with no significant differences (P < 0.05) between the control treatment and all of the treated litters, 1 d after applying the blends and 2.35, 6.63, 6.43, 6.13, and 6.34 g/kg, respectively with significant differences (P < 0.05) between the control treatment and all of the treated litters, 42 d after applying the blends. The N content was significantly reduced in the control treatment due to the volatilization of NH3 and increased in the treated litter due to a reduction in this NH3 volatilization. The treated litters had a high N content after 42 d, with no significant difference observed between these. Other studies have also reported that the use of aluminum sulfate can increase the N content of poultry litter [33]. Furthermore, studies conducted by Sims and Luka-McCafferty [35] revealed that the average N content increased as the pH decreased, and Moore et al. [18,19] suggested that the additional N in the litter in the form of ammonium arises from low NH3 volatilization. Therefore, it is hypothesized that an aluminum sulfate/ferric chloride blend reduces the pH and NH3 volatilization and improves the N content of poultry litter. The average water-soluble P concentrations in the control, T1, T2, T3, and T4 were 1.93, 1.57, 1.77, 1.63, and 1.65 g/kg, respectively, 1 d after applying the blends and 0.88, 0.72, 0.77, 0.83, and 0.80 g/kg, respectively, 42 d after applying the blends (Table 3). Water-soluble P concentrations were also significantly reduced following the application of aluminum sulfate and ferric chloride. Though there was little difference between the treated litters after 1 d, a slight difference was observed between all treatments after 6 wk. These lower water-soluble P concentrations are consistent with the results of other studies and may be due to the formation of amorphous aluminum hydroxides when Al3+ dissociates from aluminum sulfate and hydrolyzes in alkaline litter [19]. Also Peak and Hunger revealed that alum decreases water-soluble P in poultry litter by forming insoluble AlPO4 hydroxides and Al(OH)3-phosphate surface adsorption complexes [36–37]. Our study showed that litter amendment with alum and ferric chloride blend could be considered as a key tool for reducing runoff and leaching losses of soluble nutrients. At the end of study the total phosphorus of untreated litter were higher than treated litter but in comparison with initial total phosphorus the concentration were reduce. The average total P concentrations in the control, T1, T2, T3, and T4 were 1.93, 1.57, 1.77, 1.63, and 1.65 g/kg, respectively, 1 d after applying the blends and 0.954, 0.72, 0.77, 0.83, and 0.80 g/kg, respectively, 42 d after applying the blends (Table 3). The results of our study are similar to previous laboratory studies, albeit with a lower nutrient concentration due to the lower ratio of manure to sawdust used. CONCLUSIONS AND APPLICATIONS The application of aluminum sulfate/ferric chloride blends at different concentrations greatly reduced the pH, moisture content, and NH3 volatilizations from poultry litter, with 50 + 50 and 25 + 50 g/kg concentrations of aluminum sulfate and ferric chloride, respectively, having the largest effects. A higher ferric chloride concentration (25 + 50 g/kg) in the blend was more effective than a higher aluminum sulfate concentration (50 + 25 g/kg). Various concentrations of the blend increased the N in treated litter and decreased in untreated litter and reduced the water-soluble P content of treated poultry litter. There was a clear difference in CO2 and NH3 volatilizations of the treated and control litters. However, other factors, such as time, temperature, and humidity, also affected these concentrations. Further studies are required that use different concentrations of the blend in a farm evaluation and laboratory experiment. Footnotes Primary Audience: Researchers, Agriculture Engineers, Nutritionists, Poultry Industry REFERENCES AND NOTES 1. Cabrera M L., Chiang S. C.. 1994. Water content effect on denitrification and ammonia volatilization in poultry litter. Soil Sci. Soc. Am. J.  58: 811– 816. Google Scholar CrossRef Search ADS   2. Reece F. N., Lott B. D., Deaton J W.. 1980. Ammonia in the atmosphere during brooding affects performance of broiler chickens. Poult. Sci.  59: 486– 488. Google Scholar CrossRef Search ADS   3. Carlile F. S. 1984. Ammonia in poultry houses: A literature review. World. Poult. Sci. J.  40: 99– 113. Google Scholar CrossRef Search ADS   4. Miles D. M., Branton S. L., Lott B. D.. 2004. Atmospheric ammonia is detrimental to the performance of modern commercial broilers. Poult. Sci.  83: 1650– 1654. Google Scholar CrossRef Search ADS PubMed  5. Nuernberg G. B., Moreira M. A., Ernani P. R., Almeida J. A., Maciel T. M.. 2016. Efficiency of basalt zeolite and Cuban zeolite to adsorb ammonia released from poultry litter. J. Env. Manag.  183: 667– 672. Google Scholar CrossRef Search ADS   6. Rothrock Jr M. J., Szogi A. A., Vanotti M B.. 2011. Recovery of ammonia from poultry litter using gas-permeable membranes. Trans. ASABE  53: 1267– 1275. Google Scholar CrossRef Search ADS   7. Battye R., Battye W., Overcash C., Fudge S.. 1994. Development and selection of ammonia emission factors. EPA contract ( 68-D3), 0034. 8. European Environment Agency, 2013. European Union emission inventory report (1990–2011). https://www.eea.europa.eu/. 9. Gas, Production of Ammonia. “Ammonia emission from poultry industry, its effects and mitigation mechanism.” 10. Miles D M., Brooks J. P., Mclaughlin M. R., Rowe D. E.. 2013. Broiler litter ammonia emissions near sidewalls, feeders, and waterers. Poult. Sci.  92: 1693– 1698. Google Scholar CrossRef Search ADS PubMed  11. Worley J W., Czarick M., Cathey A M.. 2002. Ammonia emissions from a commercial broiler house. In 2002 ASAE Annual Meeting (p. 1) . American Society of Agricultural and Biological Engineers. 12. Li H., Xin H., Liang Y., Burns R T.. 2008. Reduction of ammonia concentrations from stored laying hen manure through topical application of zeolite, Al+ Clear, Ferix-3, or poultry litter treatment. J. Appl. Poult. Res.  17: 421– 431. Google Scholar CrossRef Search ADS   13. Singh A., Bicudo J. R., Tinoco A. L., Tinoco I. F., Gates R. S., Casey K. D., Pescatore A. J.. 2004. Characterization of nutrients in built-up broiler litter using trench and random walk sampling methods. J. Appl. Poult. Res.  13: 426– 432. Google Scholar CrossRef Search ADS   14. Dekisissa T., Short I., Allen J. ( 2008, July). Effect of soil amendment with compost on growth and water use efficiency of Amarnnath. In Proc. UCOWR/NIWR Annual Conf.: Int. Water Res.: Challenges for the 21st Century and Water Resources Education . 15. EPA. 2012b. Potential environmental impacts of animal feeding operations. Agriculture 101 , U.S. Environmental Protection Agency, Washington, D.C. 16. Moore P. A., Miller D. M.. 1994. Decreasing phosphorus solubility in poultry litter with aluminum, calcium, and iron amendments. J. Env. Qual.  23: 325– 330. Google Scholar CrossRef Search ADS   17. Moore P A., Daniel T. C., Edwards D. R., Miller D. M.. 1996. Evaluation of chemical amendments to reduce ammonia volatilization from poultry litter. Poult. Sci.  75: 315– 320. Google Scholar CrossRef Search ADS PubMed  18. Moore P. A., Daniel T. C., Gilmour J. T., Shreve B. R., Edwards D. R., Wood B. H.. 1998. Decreasing metal runoff from poultry litter with aluminum sulfate. J. Env. Qual.  27: 92– 99. Google Scholar CrossRef Search ADS   19. Moore P A., Daniel T., Edwards D. R.. 2000. Reducing phosphorus runoff and inhibiting ammonia loss from poultry manure with aluminum sulfate. J. Env. Qual.  29: 37– 49. Google Scholar CrossRef Search ADS   20. Boyd C E., Massaut L.. 1999. Risks associated with the use of chemicals in pond aquaculture. Aquacult. Engin.  20: 113– 132. Google Scholar CrossRef Search ADS   21. AOAC. 1995. Official Methods of Analysis. 16th ed. Assoc. Off. Anal. Chem ., Arlington, VA. 22. Fisher Scientific Research, Pittsburgh, Pa. 23. Gastec Ammonia Detector Tubes - Zefon International, Inc. http://www.zefon.com/. 24. Model ZDL-800 electrochemical monitor, Environmental sensors, Boca Raton, FL. 25. Lutron Electronic, CO2/Humidity/Temp. Monitor, Model: MCH-383SD, ISO-9001, CE, IEC1010. 26. Trumac Series Macro Determinator- Leco. https://www.leco.com/. 27. DB-1 Stainless Steel Hot Plate. 28. Zarcinas B A., Cartwright B., Spouncer. L. R. 1987. Nitric acid digestion and multi‐element analysis of plant material by inductively coupled plasma spectrometry. Commun. Soil Sci. Plant Anal.  18: 131– 146. Google Scholar CrossRef Search ADS   29. MF-Millipore™ Membrane Filters - Filter Discs and Membranes. http://www.merckmillipore.com/KR/ko. 30. Graph Pad Prism Software, for Mac and Windows Inc. USA 31. Choi I. H., Moore P. A.. 2008. Effect of various litter amendments on ammonia volatilization and nitrogen content of poultry litter. J. Appl. Poult. Res.  17. 4: 454– 462. Google Scholar CrossRef Search ADS   32. Choi I. H., Moore P. A.. 2008. Effects of liquid aluminum chloride additions to poultry litter on broiler performance, ammonia emissions, soluble phosphorus, total volatile fatty acids, and nitrogen contents of litter. Poult. Sci.  87: 1955– 1963. Google Scholar CrossRef Search ADS PubMed  33. Do J. C., Choi I. H., Nahm K. H.. 2005. Effects of chemically amended litter on broiler performances, atmospheric ammonia emission, and phosphorus solubility in litter. Poult. Sci.  84: 679– 686. Google Scholar CrossRef Search ADS PubMed  34. Madrid J., Lopez M. J., Orengo J., Martinez S., Valverde M., Megias M. D., Hernandez F.. 2012. Effect of aluminum sulfate on litter composition and ammonia emission in a single flock of broilers up to 42 d of age. Animal: an international J. animal bioscience  6: 1322. Google Scholar CrossRef Search ADS   35. Sims J. T., Luka-Mccafferty N. J.. 2002. On-farm evaluation of aluminum sulfate (alum) as a poultry litter amendment. J. Env. Qual.  31: 2066– 2073. Google Scholar CrossRef Search ADS   36. Peak D., Sims J. T., Sparks D. L.. 2002. Solid-state speciation of natural and alum-amended poultry litter using XANES spectroscopy. Environ. Sci. Technol.  36: 4253– 4261 Google Scholar CrossRef Search ADS PubMed  37. Hunger S., Cho H., Sims J. T., Sparks D. L.. 2004. Direct speciation of phosphorus in alum-amended poultry litter: Solid-state 31P NMR investigation. Environ. Sci. Technol.  38: 674– 681. Google Scholar CrossRef Search ADS PubMed  Acknowledgements This research was supported by Korea Institute of Planning and Evaluation for technology in Food, Agriculture, Forestry and Fisheries (IPET) through Research Centre Support Program (Project No. 717001-7) , Ministry of Agriculture, Food and Rural affairs (MAFRA). © 2017 Poultry Science Association Inc. http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png Journal of Applied Poultry Research Oxford University Press

Effects of an Aluminum Sulfate and Ferric Chloride Blend on Poultry Litter Characteristics in Vitro

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Oxford University Press
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© 2017 Poultry Science Association Inc.
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1056-6171
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1537-0437
D.O.I.
10.3382/japr/pfx046
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Abstract

Abstract Previous studies have applied various concentrations of aluminum sulfate and ferric chloride separately to poultry litter to reduce environmental pollution and increase chicken productivity. In the present study, we investigated the effect of using a blend of these 2 chemicals under 5 different treatments: control (no addition), 50 + 50, 25 + 50, 50 + 25, and 25 + 25 g/kg of litter, which consisted of fresh chicken manure (1 kg) and sawdust (4 kg) thoroughly mixed in a 70 × 47 × 43 cm box. NH3 and CO2 volatilizations, pH, electrical conductivity (EC) and moisture content of the poultry litter were assessed weekly up to 6 wk and in the case of total and water-soluble nutrients they were assessed after 1 and 42 d. The control treatment had higher NH3 and CO2 volatilizations than the treated litter throughout the experiment. EC and pH showed an inverse relationship, whereby the control treatment had high pH and low EC values and the treated litter had low pH and high EC values. After 42 d, nitrogen levels were significantly reduced in the control treatment, whereas the 50 + 50 g/kg treatment had the highest content. Conversely, water-soluble phosphorus levels were much lower in the treated poultry litter after 1 and 42 d. A higher ferric chloride concentration (25 + 50 g/kg) in the blend was more effective than a higher aluminum sulfate concentration (50 + 25 g/kg). These findings demonstrate that a combination of aluminum sulfate and ferric chloride may be a useful amendment for reducing NH3 and CO2 volatilizations, pH, and moisture content of poultry litter, which will help in improving poultry productivity, pollution control, and poultry litter fertilizer usage. DESCRIPTION OF PROBLEM Control of pollution arising from many different sources is a big challenge globally. The poultry industry is one growing source of pollution due to production of harmful gases, such as NH3, CO2, CH4, and N2O, which not only affect the environment but also have a direct impact on chicken health and productivity. Poultry litter is a mixture of bedding material, excreta, and waste feed generated during poultry production and is the main cause of the production of these various gases [1]. Among these gases, NH3 is the most important from an environmental and health perspective and therefore, its volatilizations need to be mitigated. NH3 gas volatilization above 25 ppm in a poultry house is harmful for chickens, reducing their performance [2–4]. Both the concentration and exposure time of birds to ammonia may effect health of birds and workers, such as tracheal irritation, eye damage, decreased feed efficiency and mortality [5]. The removal of gaseous ammonia from poultry litter can benefit bird health and productivity and reduce environmental concerns of emissions from poultry production [6]. Furthermore, manure storage sites also act as a source of NH3. Therefore, as the poultry industry expands, there is increasing concern about the release of such gases. Countries that are more dependent on agriculture and the livestock industry will face an increasing issue with pollution unless its sources are addressed [7]. In the United States, more than 80% of NH3 arises from agricultural sources [7], and France and Germany produce more NH3 gas than any other European country [8]. It is estimated that 26.7% of NH3 volatilizations arise from poultry production, which is second only to cattle farming [7]. To increase bird performance, NH3 volatilization needs to be reduced. Microbial breakdown of wastes of birds results in the formation of NH3 as bird manure is rich in nitrogen [9]. The level of volatilizations from this manure depends on the conditions, with a pH > 7, high moisture levels, and warm temperatures being required for the production of NH3 gas, leading to seasonal variation in NH3 volatilizations [9]. Factors which cause NH3 generation include physical and chemical litter properties (temperature, moisture, pH, and N content), type of original bedding material, and spatial characteristics of gas evolution within houses [10]. In addition, CO2 and CH4 volatilization need to be considered because they affect chicken performance and weight. For example, exposure of chickens to 12,000 ppm of CO2 decreases body weight by approximately 60 g at 4 wk of age, and this persists until 7 wk of age [2]. For CO2, the maximum 8-h exposure limit is 5,000 ppm and the maximum 15-min exposure limit is 30,000 ppm [11]. CO2 concentrations from the poultry industry can be reduced in 2 ways. First, because CO2 and NH3 mainly arise from the breakdown of uric acid by bacteria, treatments reduce microbial activity by lowering pH. Second, CO2 concentrations can be reduced using less fuel for heating and ventilation in the poultry house [12]. Because of the high demand for chicken products, many methods have been used in the past to control the concentration of these gases in poultry houses and improve the health of chickens, including improving the ventilation system, controlling nutrients in the diet, and adding chemicals to poultry manure (litter amendment). However, some of these are very expensive, and therefore, more cost-effective methods are required to increase chicken productivity. Poultry litter is considered to be the best source of organic material and can be used as a fertilizer [13]. Poultry manure is not only beneficial for crop production because of its high nutrient content but also improves the structural stability of the soil [14]. Poultry litter can be applied fresh or after composting [13], although fresh litter may contain an imbalance of nutrients. The most important nutrients for increasing soil fertility are nitrogen, phosphorus, and potassium (NPK). N and P are of primary environmental importance for poultry broiler production [15]. Many compounds are available to reduce NH3. Aluminum sulfate is unique chemical for litter amendment as it not only reduces NH3 volatilizations but also reduces P solubility and N loss [16–19]. Additional chemicals that are used commercially as litter treatments include ferric chloride, ferric sulfate and sodium bisulfate. These amendments act by either inhibiting microbial transformation of urea or uric acid into NH3 or by acidification and subsequent conversion of volatile NH3 to non-volatile ammonium (NH4+) [6]. Some of these chemicals are widely used by farmers, whereas others have a more limited application because their high costs prohibit them from being used at a large scale. Moreover, people are generally reluctant to use these chemicals because direct exposure to some of them can cause health issues. Aluminum sulfate and ferric chloride both should be handled with care because skin irritation can result from contact [20]. However, the effectiveness of blending 2 chemicals has not yet been fully realized. Therefore, the objective of this study was to evaluate the effectiveness of using a blend of aluminum sulfate and ferric chloride to alter poultry litter characteristics under laboratory condition, i.e., NH3 and CO2 volatilizations, pH, electrical conductivity (EC), moisture content, and total and water-soluble nutrient contents. MATERIALS AND METHODS Experimental Design This study was conducted at Gyeongsang National University, South Korea. The poultry litter used in the experiment was a mixture of fresh chicken manure and sawdust, which had moisture contents of 77% and 24%, respectively. In total, 1 kg of manure and 4 kg of sawdust were mixed thoroughly and placed to a depth of 9 cm in plastic rectangular boxes (70 × 47 × 43 cm) that had 2 8-cm-diameter holes on opposite sides for inlet and outlet of air (Figure 1). These boxes were kept in a room that was maintained at a temperature of approximately 25°C throughout the experiment. After mixing manure and sawdust the gases volatilization varies quickly and there were much difference in all boxes in first few d. To minimize the difference the litter was left in the boxes for 1 wk before treatment, which consisted of a blend of aluminum sulfate [Al2(SO4)3 ⋅ 14H2O] and ferric chloride (FeCl3). To determine effective ratio of blending 2 chemicals for management of poultry litter 5 different treatments were used with 3 replicates per treatment: control (no chemicals), T1 (50 + 50 g/kg), T2 (25 + 50 g/kg), T3 (50 + 25 g/kg), and T4 (25 + 25 g/kg), where the concentrations represent aluminum sulfate + ferric chloride gram per kilogram of litter. Figure 1. View largeDownload slide Schematic diagram of boxes for storage of poultry litter. Figure 1. View largeDownload slide Schematic diagram of boxes for storage of poultry litter. Because this was a laboratory experiment, the chickens were not reared on litter, and therefore, the proportion of manure in the sawdust was lower than that in normal poultry litter. In poultry houses, continuous addition of water and manure results in the chemicals being covered with manure, which increases the alkalinity and pH more readily. Litter Sampling Prior to adding the aluminum sulfate/ferric chloride blends, NH3 and CO2 volatilizations above the poultry litter were assessed. Samples were taken at 5 random depths between the top and bottom of the litter and mixed together, with 3 replicates per treatment. Three subsamples were then taken to assess pH, EC, and moisture content. Each of these parameters was then reassessed 2 h after applying the blends, and additional litter samples were analyzed on a weekly basis for 6 wk. EC, pH, and Moisture Content EC and pH of the litter samples were determined by adding 100 mL of distilled water to 10 g of litter in a beaker and mixing thoroughly for 5 min [21]. The litter slurry was then allowed to settle for 10 min. EC and pH were measured using a digital EC and pH meter [22]. The moisture content of the litter was determined by taking 3 samples with an initial wet weight of 10 g from each treatment. These samples were dried in an oven for 24 h at 105°C and then reweighed to calculate the moisture content [22]. NH3 and CO2 Volatilization Measurements Atmospheric NH3 was determined 10 cm above the litter in each box using 2 methods: Gastec ammonia tubes [23] and an electrochemical sensor (“ZDL800” ammonia meter) [24]. Gastec ammonia tubes with a range of 0.5–70 ppm were used to check NH3 volatilizations at the center of each box on a weekly basis. In addition, the ZDL800 ammonia meter was used in parallel to check the accuracy of these readings. Because the exposure of an electrochemical sensor to high concentrations of NH3 over long periods leads to error in the readings, the ZDL800 sensor was used for 1 h every 3 d to check each box, and data were transferred to PC. This sensor is equipped to store the date, time, number of exposure points, interval between each point, and actual exposure points. Average weekly data from the ZDL800 ammonia meter were used for analysis. The % reduction in NH3 was calculated by the following equation:   \begin{eqnarray*} &&{{\rm{N}}{{\rm{H}}_3}\% \,{\rm{reduction}}}\nonumber\\ &&\quad = \frac{{{\rm{N}}{{\rm{H}}_3}({\rm{initial}}) - {\rm{N}}{{\rm{H}}_3}({\rm{final}})}}{{{\rm{N}}{{\rm{H}}_3}({\rm{initial}})}} \times 100 \end{eqnarray*} CO2 was measured by placing a “Lutron MCH-383SD” electrochemical sensor [25] in each box. Lutron MCH-383SD is equipped to record the date, time interval, and number of exposure points and has a memory card to store these data. CO2 was checked at 10-min intervals over 24 h on every 3 d, and weekly recorded data were averaged for further analysis and interpretation. The % reduction in CO2 was calculated by the following equation:   \begin{eqnarray*} &&{{\rm{C}}{{\rm{O}}_2}\% \,{\rm{reduction}}}\nonumber\\ &&\quad = \frac{{{\rm{C}}{{\rm{O}}_2}({\rm{initial}}) - {\rm{C}}{{\rm{O}}_2}({\rm{final}})}}{{{\rm{C}}{{\rm{O}}_2}({\rm{initial}})}} \times 100 \end{eqnarray*} The volatilization reduction rate (%) was calculated by the following equation   \begin{eqnarray*} &&{{\rm{Volatilization}}\,{\rm{Reduction}}\,{\rm{rate}}\left( {\rm{\% }} \right)}\nonumber\\ &&\quad = \frac{{{\rm{CV}}\,\left( {{\rm{control}}} \right)\, - \,{\rm{CV}}\,\left( {{\rm{Treatment}}} \right)}}{{{\rm{CV}}\left( {{\rm{Control}}} \right)}} \times 100 \end{eqnarray*} CV: Cumulative Volatilization Nutrient Analysis The total C, N, P, K, Fe and Al contents of the litter were measured 1 and 42 d after applying the blends. as were the concentrations of water-soluble P, Fe, and Al using 20-g subsamples. The total C and N percentages were determined by the dry combustion method using a Model 2000 LECO (St. Joseph, MI) CNS analyzer [26]. Moist samples were used for this analysis because oven drying results in N losses [12]. Total P, K, Fe and Al contents were determined by oven drying the litter at 60°C, digesting it with HNO3 [27], and analyzing the digested samples using inductively coupled plasma (ICP) emission spectrometry [28]. Water-soluble P, Al, and Fe contents were measured by shaking the wet litter with deionized water (1:10 litter to water ratio) for 2 h, followed by centrifugation and filtration through 0.45-μm Millipore (Bedford, MA) filter paper [29]. Each element concentration in the filtrate was then determined by ICP emission spectrometry [28]. Statistical Analysis Statistical analysis was performed using the Prism 5 Graph Pad program [30]. Data were presented as means ± SEM and analyzed by one-way ANOVA followed by Bonferroni's Multiple Comparison Test with a significance level of P < 0.05. RESULTS AND DISCUSSION NH3 and CO2 Volatilizations The initial volatilizations of NH3 in the Control, T1, T2, T3, and T4 were 80, 84, 86, 83, and 81 ppm, respectively. Because no further manure or water was added during this experiment, atmospheric NH3 in the untreated litter (control) decreased to 60, 35, 25, 17, 16, and 14 ppm at wk 1, 2, 3, 4, 5, and 6, respectively, representing an 83.7% reduction after 6 wk (Figure 2). Conversely, in T1, the NH3 volatilization was 0, 0.1, 0.4, 1.13, 3.25, and 4.9 ppm at wk 1, 2, 3, 4, 5, and 6, respectively, representing a 94.3% reduction after 6 wk compared with the initial level. In T2, the NH3 volatilization was 0, 0.1, 0.35, 1.4. 3.75, and 5.1 ppm at wk 1, 2, 3, 4, 5, and 6, respectively, representing a 94% reduction after 6 wk. In T3, the NH3 volatilization was 0, 0.2, 0.75, 2.7, 4.75, and 6.2 ppm at wk 1, 2, 3, 4, 5, and 6, respectively, representing a 92.5% reduction after 6 wk. In T4, the NH3 volatilization was 0, 0.2, 0.85, 3.1, 5.4, and 7.3 ppm at wk 1, 2, 3, 4, 5, and 6, respectively, representing a 90.9% reduction after 6 wk. The cumulative NH3 volatilization reduction rates relative to the control treatment are presented in Table 1. Figure 2. View largeDownload slide Ammonia and carbon dioxide volatilization (means ± SEM) from poultry litter with various concentration of blends. Control (no treatment); T1: 50 + 50 g/kg; T2: 25 + 50 g/kg; T3: 50 + 25 g/kg; and T4: 25 + 25 g/kg (expressed as aluminum sulfate + ferric chloride per kilogram of litter). Figure 2. View largeDownload slide Ammonia and carbon dioxide volatilization (means ± SEM) from poultry litter with various concentration of blends. Control (no treatment); T1: 50 + 50 g/kg; T2: 25 + 50 g/kg; T3: 50 + 25 g/kg; and T4: 25 + 25 g/kg (expressed as aluminum sulfate + ferric chloride per kilogram of litter). Table 1. NH3 and CO2 volatilization reduction rates (%) from poultry litter over 6 wk following the addition of various aluminum sulfate/ferric chloride blends. Values are relative to the control treatment.   VR% NH3  VR% CO2  Treatments  Week  1  2  3  4  5  6  Week  1  2  3  4  5  6  T11    100a ± 0  99.7a ± 0.02  98.4a,b ± 0.08  93.3c ± 0.08  79.6d ± 0.11  65.1e ± 0.46    24.1a ± 0.23  24.5a ± 0.2  21.1b ± 0.23  46.5c ± 0.2  44.5d ± 0.21  44.3d ± 0.17  T21    100a ± 0  99.7a ± 0.05  98.6a,b ± 0.04  93.2c ± 0.07  76.5d ± 0.04  63.5e ± 0.15    20.9a ± 0.23  24.5b ± 0.11  17c ± 0.26  41.2d ± 0.18  42.4d,e ± 0.04  38.4f ± 0.02  T31    100a ± 0  99.4a ± 05  97b ± 0.23  84.1c ± 0.1  70.3d ± 0.1  55.7e ± 0.06    14.6a ± 0.12  27.8b ± 0.18  12c ± 0.31  40.3d ± 0.14  34.5e ± 0.2  28.1b ± 0.11  T41    100a ± 0  99.4a ± 0.03  97b ± 0.04  84.1c ± 0.02  70.3d ± 0.14  55.7e ± 0.06    18.3a ± 0.11  23.8b ± 0.04  7.5c ± 0.13  30.8d ± 0.07  32.6e ± 0.05  29.3f ± 0.04    VR% NH3  VR% CO2  Treatments  Week  1  2  3  4  5  6  Week  1  2  3  4  5  6  T11    100a ± 0  99.7a ± 0.02  98.4a,b ± 0.08  93.3c ± 0.08  79.6d ± 0.11  65.1e ± 0.46    24.1a ± 0.23  24.5a ± 0.2  21.1b ± 0.23  46.5c ± 0.2  44.5d ± 0.21  44.3d ± 0.17  T21    100a ± 0  99.7a ± 0.05  98.6a,b ± 0.04  93.2c ± 0.07  76.5d ± 0.04  63.5e ± 0.15    20.9a ± 0.23  24.5b ± 0.11  17c ± 0.26  41.2d ± 0.18  42.4d,e ± 0.04  38.4f ± 0.02  T31    100a ± 0  99.4a ± 05  97b ± 0.23  84.1c ± 0.1  70.3d ± 0.1  55.7e ± 0.06    14.6a ± 0.12  27.8b ± 0.18  12c ± 0.31  40.3d ± 0.14  34.5e ± 0.2  28.1b ± 0.11  T41    100a ± 0  99.4a ± 0.03  97b ± 0.04  84.1c ± 0.02  70.3d ± 0.14  55.7e ± 0.06    18.3a ± 0.11  23.8b ± 0.04  7.5c ± 0.13  30.8d ± 0.07  32.6e ± 0.05  29.3f ± 0.04  Notes: Percentage of concentration reduction on a weekly basis compared with the control treatment. $${\rm{Volatilization\ }}\,\,{\rm{Reduction}}\,\,{\rm{rate\ }}( {\rm{\% }} ) = \frac{{{\rm{CV\ }}( {{\rm{control}}} ){\rm{\ }} - {\rm{\ CV\ }}( {{\rm{Treatment}}} )}}{{{\rm{CV\ }}( {{\rm{Control}}} )}} \times 100$$ VR: Volatilization Reduction, CV: Cumulative Volatilization. a–eMeans in a row having different superscripts are significantly different (P < 0.05). 1Application of the chemical blend Al2(SO4)3 · 14H2O + FeCl3 at a concentration of 50 + 50 g/kg (T1), 25 + 50 g/kg (T2), 50 + 25 g/kg (T3), and 25 + 25 g/kg (T4). View Large CO2 volatilizations were reduced in all treatments. However, the addition of an aluminum sulfate/ferric chloride blend caused this reduction to occur more quickly. The initial CO2 volatilizations in the control, T1, T2, T3, and T4 were 1,188, 1,134, 1,093, 1,195, and 1,146 ppm, respectively. After applying the blends, the CO2 volatilization and temperature of the litter suddenly increased because of reaction of the chemicals and then reduced after 1 d. The average CO2 volatilizations at the end of the 6th wk were 679, 378, 418, 488, and 480 ppm in the control, T1, T2, T3 and T4, respectively, representing a 42.8%, 66.6%, 61.7%, 59.1%, and 58.1% reduction in each. The cumulative CO2 volatilization reduction rates relative to the control treatment are shown in Table 1. These findings demonstrate that the addition of an aluminum sulfate/ferric chloride blend to poultry litter dramatically reduces NH3 and CO2 volatilizations. Furthermore, the use of higher volatilizations of aluminum sulfate and ferric chloride led to greater reductions in NH3 than those with the use of lower volatilizations because the NH3 volatilization was nearly zero after the first 2 wk but then slowly began to be emitted in all treatments. NH3 volatilizations of T1 and T2 were nearly identical throughout the experiment (P > 0.05) and were lower than those of T3 and T4. Significant differences were observed between the control treatment and all of the blend treatments over 6 wk (P < 0.05), and at the end of the 6-wk period, there were also significant differences between T1 and T4 and between T2 and T4 (P < 0.05). Moore [19] previously showed that NH3 volatilizations were greatly reduced following the application of aluminum sulfate. Similarly, Choi reported that the application of aluminum sulfate led to an 87% reduction in NH3 after 42 d compared with the control treatment [31] and that the use of aluminum sulfate reduced NH3 volatilizations by 77%–96% [32]. Ferric chloride has also been shown to greatly reduce NH3 at a range of volatilizations. In the present study, it was found that a rate of 25 g/kg aluminum sulfate + 50 g/kg ferric chloride was more effective than 50 g/kg aluminum sulfate + 25 g/kg ferric chloride in reducing NH3 volatilizations and pH of the litter. The average NH3 volatilization reductions were 89.3%, 88.5%, 84.4%, and 81.9% for T1, T2, T3, and T4, respectively, as shown in Figure 3. Figure 3. View largeDownload slide Comparison of ammonia and carbon dioxide volatilization reduction (VR) % between treated litters of 6 wk. T1: 50 + 50 g/kg; T2: 25 + 50 g/kg; T3: 50 + 25 g/kg; and T4: 25 + 25 g/kg (expressed as aluminum sulfate + ferric chloride per kilogram of litter). Note: Percentage of VR presented on weekly basis compared with the control treatment and VR% are average data of 6 wk. $${\rm{Volatilization\ }}\,\,{\rm{Reduction}}\,\,{\rm{rate\ \ }}( {\rm{\% }} ) = \frac{{{\rm{CV\ }}( {{\rm{control}}} ){\rm{\ }} - {\rm{\ CV\ }}( {{\rm{Treatment}}} )}}{{{\rm{CV\ }}( {{\rm{Control}}} )}}{\rm{\ \ }} \times {\rm{\ }}100$$ CV: Cumulative Volatilization. In this case control treatment cannot be calculated by this formula. Figure 3. View largeDownload slide Comparison of ammonia and carbon dioxide volatilization reduction (VR) % between treated litters of 6 wk. T1: 50 + 50 g/kg; T2: 25 + 50 g/kg; T3: 50 + 25 g/kg; and T4: 25 + 25 g/kg (expressed as aluminum sulfate + ferric chloride per kilogram of litter). Note: Percentage of VR presented on weekly basis compared with the control treatment and VR% are average data of 6 wk. $${\rm{Volatilization\ }}\,\,{\rm{Reduction}}\,\,{\rm{rate\ \ }}( {\rm{\% }} ) = \frac{{{\rm{CV\ }}( {{\rm{control}}} ){\rm{\ }} - {\rm{\ CV\ }}( {{\rm{Treatment}}} )}}{{{\rm{CV\ }}( {{\rm{Control}}} )}}{\rm{\ \ }} \times {\rm{\ }}100$$ CV: Cumulative Volatilization. In this case control treatment cannot be calculated by this formula. The CO2 volatilization reduction rates relative to the control treatment over all 6 wk are shown in Table 1. The average CO2 volatilization reductions were 34.1%, 30.7%, 26.2%, and 23.7% for T1, T2, T3, and T4, respectively, as shown in Figure 3. Li [12] previously reported that CO2 volatilizations of a poultry house could be reduced by reducing the microbial activity or fuel consumption. In this study, the pH and moisture content of poultry litter were reduced by applying a blend that made the conditions unfavorable for microorganisms to survive, causing CO2 volatilizations to decrease over time. CO2 volatilizations were higher for the control treatment than for all other treatments because of the slight reduction in pH and slow rate of moisture content reduction, with all treatments except T3 and T4 showing a significant difference from the control treatment after 6 wk (P < 0.05). pH, EC, and Moisture Content Application of a blend of aluminum sulfate and ferric chloride at various concentrations had a significant effect on the pH, EC (mS/cm), and percent moisture content (MC) of the poultry litter. Before applying the blends, initial values of each of these were almost identical across treatments. Average values for pH, EC, and MC are presented in Table 2, illustrating how the blends affected these parameters during the 6-wk period. Table 2. Effects of various aluminum sulfate/ferric chloride blends on the pH, electrical conductivity (EC), and moisture content (MC) of poultry litter over 6 wk. Items  pH  EC(mS/cm)  MC%  Wk  C  T1  T2  T3  T4  C  T1  T2  T3  T4  C  T1  T2  T3  T4  1  8.04a ± 0.015  3.7b ± 0.005  3c ± 0.008  3.88d ± 0.008  4.06e ± 0.012  1.54a ± 0.01  9.76b ± 0.90  9.68b ± 0.31  7.42b,c ± 0.65  7.98b,c ± 0.47  35.2a ± 0.16  33.4b ± 0.3  33.8b ± 0.12  33.7b ± 0.13  33.8b ± 0.20  2  7.3a ± 0.012  3.72b,c ± 0.014  3.62c ± 0.014  4.03d ± 0.012  4.3e ± 0.008  1.63a ± 0.03  9.51b ± 0.15  9.14b ± 0.25  6.51c ± 0.05  6.41c ± 0.05  33.7a ± 0.03  31.8a,b ± 0.12  32.1a–c ± 0.17  32.2a–c ± 0.03  33a ± 0.31  3  7.25a ± 0.017  3.68b ± 0.017  3.58b,c ± 0.016  4.1d ± 0.005  4.29e ± 0.014  1.69a ± 0.01  8.74b ± 0.14  9.12b ± 0.18  7.01c ± 0.12  6.85c ± 0.34  30.9a ± 0.08  27b ± 0.16  28.6c ± 0.14  27.9c ± 0.13  29.3c ± 0.08  4  7.21a ± 0.015  3.81b ± 0.005  3.71c ± 0.017  4.05d ± 0.005  4.43e ± 0.003  1.76a ± 0.05  9.65b ± 0.34  9.41b ± 0.14  7.45c ± 0.12  6.75c ± 0.08  31.1a ± 0.42  25.6b ± 0.12  26.5b ± 0.26  25.9b ± 0.18  29.1c ± 0.53  5  7.15a ± 0.04  3.77b ± 0.015  3.7b ± 0.021  4.07c ± 0.005  4.5d ± 0.02  1.5a ± 0.02  8.75b ± 0.06  8.71b ± 0.03  8.16b,c ± 0.23  6.86c ± 0.19  28.7a ± 0.1  25b ± 0.12  26b ± 0.1  25.3b ± 0.14  27.5a ± 0.06  6  7.1a ± 0.008  3.79b ± 0.011  3.72b ± 0.003  4.09c ± 0.02  4.51d ± 0.02  1.68a ± 0.03  9.33b ± 0.3  9.4b ± 0.24  7.9c ± 0.01  7.66c ± 0.14  25.3a ± 0.05  20.9b ± 0.12  22.5b ± 0.05  21.8b ± 0.03  25.1a ± 003  Items  pH  EC(mS/cm)  MC%  Wk  C  T1  T2  T3  T4  C  T1  T2  T3  T4  C  T1  T2  T3  T4  1  8.04a ± 0.015  3.7b ± 0.005  3c ± 0.008  3.88d ± 0.008  4.06e ± 0.012  1.54a ± 0.01  9.76b ± 0.90  9.68b ± 0.31  7.42b,c ± 0.65  7.98b,c ± 0.47  35.2a ± 0.16  33.4b ± 0.3  33.8b ± 0.12  33.7b ± 0.13  33.8b ± 0.20  2  7.3a ± 0.012  3.72b,c ± 0.014  3.62c ± 0.014  4.03d ± 0.012  4.3e ± 0.008  1.63a ± 0.03  9.51b ± 0.15  9.14b ± 0.25  6.51c ± 0.05  6.41c ± 0.05  33.7a ± 0.03  31.8a,b ± 0.12  32.1a–c ± 0.17  32.2a–c ± 0.03  33a ± 0.31  3  7.25a ± 0.017  3.68b ± 0.017  3.58b,c ± 0.016  4.1d ± 0.005  4.29e ± 0.014  1.69a ± 0.01  8.74b ± 0.14  9.12b ± 0.18  7.01c ± 0.12  6.85c ± 0.34  30.9a ± 0.08  27b ± 0.16  28.6c ± 0.14  27.9c ± 0.13  29.3c ± 0.08  4  7.21a ± 0.015  3.81b ± 0.005  3.71c ± 0.017  4.05d ± 0.005  4.43e ± 0.003  1.76a ± 0.05  9.65b ± 0.34  9.41b ± 0.14  7.45c ± 0.12  6.75c ± 0.08  31.1a ± 0.42  25.6b ± 0.12  26.5b ± 0.26  25.9b ± 0.18  29.1c ± 0.53  5  7.15a ± 0.04  3.77b ± 0.015  3.7b ± 0.021  4.07c ± 0.005  4.5d ± 0.02  1.5a ± 0.02  8.75b ± 0.06  8.71b ± 0.03  8.16b,c ± 0.23  6.86c ± 0.19  28.7a ± 0.1  25b ± 0.12  26b ± 0.1  25.3b ± 0.14  27.5a ± 0.06  6  7.1a ± 0.008  3.79b ± 0.011  3.72b ± 0.003  4.09c ± 0.02  4.51d ± 0.02  1.68a ± 0.03  9.33b ± 0.3  9.4b ± 0.24  7.9c ± 0.01  7.66c ± 0.14  25.3a ± 0.05  20.9b ± 0.12  22.5b ± 0.05  21.8b ± 0.03  25.1a ± 003  Notes: The chemical blend Al2(SO4)3·14H2O + FeCl3 was applied. Control (no addition); T1: 50 + 50 g/kg; T2: 25 + 50 g/kg; T3: 50 + 25 g/kg; and T4: 25 + 25 g/kg (expressed as aluminum sulfate + ferric chloride per kilogram of litter). All values are expressed as means ± SEM. a–eMeans in a row having different superscripts are significantly different (P < 0.05). View Large In all treatments, the pH was dramatically reduced immediately after applying the blends and then showed an increasing trend up to 6 wk. The litter pH was significantly lower in all 4 blend treatments than that of the untreated control (P < 0.05; Table 2). Furthermore, these significant differences were observed for all 6 wk for all treatments, except T1 and T2, which were not significantly different in wk 5 and 6. The application of 50 g/kg ferric chloride with aluminum sulfate (T1 and T2) led to a greater decrease in pH than lower concentrations of ferric chloride (T3 and T4). Therefore, it appears that higher concentrations of ferric chloride in a blend are more effective in reducing the pH than higher concentrations of aluminum sulfate. EC showed an inverse relationship with pH. Application of the blends led to a reduction in the pH and a concurrent increase in EC. EC of the treated litter showed varying trends through time, but EC of the control treatment was much lower than that of the treated litter throughout the experiment. There were also significant differences in the EC values between all treatments (P < 0.05), with the exception of “T1 and T2” and “T3 and T4”, which were not significantly different over all 6 wk. The use of a higher blend concentration led to higher EC values than a lower blend concentration or no treatment (control), which is similar to the findings of Moore et al. [18], who also observed higher EC values with the application of a higher aluminum sulfate concentration. In a poultry house, the moisture content increases because of continuous addition of manure and water. However, in this experiment, the moisture content decreased by 31.6%, 43.6%, 40.6%, 41.7%, and 33.2% in the control, T1, T2, T3, and T4, respectively, after 6 wk. The use of chemicals can affect the moisture content of poultry litter. In this study, the moisture content of the control treatment litter was higher than that of the treated litter throughout the experiment, Also previous study found that chemical additives lowered the moisture content of the litter compared with the control treatment [33]. Relationship between pH and NH3 Figure 4 shows the direct positive relationship between pH and NH3 volatilizations, whereby the 2 increase or decrease simultaneously. The highest NH3 volatilizations and pH were observed in the control treatment, whereas the lowest were observed in T1. Our findings showed that manipulating the pH of the litter to ≤3.5 the NH3 volatilization becomes zero. The highest NH3 volatilization (77 ppm) and pH (8.01) were observed in the control treatment after 1 wk. Figure 4. View largeDownload slide Relationship between pH and ammonia volatilization with various concentration of blends during 6 wk. Control (no treatment); T1: 50 + 50 g/kg; T2: 25 + 50 g/kg; T3: 50 + 25 g/kg; and T4: 25 + 25 g/kg (expressed as aluminum sulfate + ferric chloride per kilogram of litter). Figure 4. View largeDownload slide Relationship between pH and ammonia volatilization with various concentration of blends during 6 wk. Control (no treatment); T1: 50 + 50 g/kg; T2: 25 + 50 g/kg; T3: 50 + 25 g/kg; and T4: 25 + 25 g/kg (expressed as aluminum sulfate + ferric chloride per kilogram of litter). Nutrient Analysis There were significant differences in some of the total and water-soluble nutrient contents between the treated and control litter after 1 and 42 d of applying the blends. In general, application of the blends led to good results, as summarized in Table 3. It was also found that nutrient concentrations in the litter varied through time. Also, the Madrid study revealed that evolution of nutrients content were dependent on time and litter treatment [34]. Table 3. Nutrients content comparison of poultry litter that was untreated (control) or treated with various aluminum sulfate/ferric chloride blends after 1 and 42 d. Nutrients  After 1 d  After 42 d  g/kg  Control  T1  T2  T3  T4  Control  T1  T2  T3  T4  Total C  270a ± 3.16  257a ± 0.83  258a ± 3.05  258.2a ± 2.03  263.2a ± 4.93  351a ± 1.20  323a ± 16.2  321a ± 2.89  315a ± 6.49  326a ± 5.53  Total N  4.97a ± 0.40  5.02a ± 0.14  5.05a ± 0.15  5.17a ± 0.62  5.84a ± 0.47  2.35a ± 0.16  6.36b ± 0.74  6.43b ± 0.94  6.13b ± 1.39  6.34b ± 0.32  Total P  1.93a ± 0.04  1.57b ± 0.06  1.777a ± 0.03  1.632b,c ± 0.02  1.657b,c ± 0.04  0.954a ± 0.02  0.72a,b ± 0.01  0.775a ± 0.007  0.838a,c ± 0.01  0.803a ± 0.01  Total K  3.097a ± 0.11  2.913a ± 0.06  3.05a ± 0.1  2.908a ± 0.04  2.94a ± 0.09  1.97a ± 0.04  1.497b ± 0.05  1.63b ± 0.04  1.685b,c ± 0.03  1.788a–c ± 0.01  Total Al  0.563a ± 0.04  5.302b ± 0.12  3.662c ± 0.07  5.232b ± 0.08  3.347c ± 0.006  0.183a ± 0.01  2.723b ± 0.04  1.926c ± 0.04  3.359d ± 0.04  2.18e ± 0.03  Total Fe  1.038a ± 0.13  20.565b ± 0.42  22.81c ± 0.38  13.183d ± 0.22  12.842d ± 0.20  0.507a ± 0.02  9.103b ± 0.14  10.231c ± 0.20  6.901d ± 0.1  7.532d ± 0.17  WS-P  1.158a ± 0.01  0.081b ± 0.004  0.078b ± 0.005  0.083b ± 0.003  0.08b ± 0.015  0.891a ± 0.05  0.094b ± 0.004  0.087b ± 0.006  0.106b ± 0.008  0.111b ± 0.007  WS-Fe  0.062a ± 0.01  2.855b ± 0.15  2.813b ± 0.02  1.535d ± 0.03  1.417d ± 0.21  0.077a ± 0.007  1.823b ± 0.06  1.869b ± 0.04  0.565c ± 0.008  0.52c ± 0.005  WS1-Al  0.071a ± 0.001  3.629b ± 0.06  1.533a ± 0.28  2.955b ± 0.62  1.425a ± 0.30  0.023a ± 0.009  2.002b ± 0.17  1.1c ± 0.03  1.508b,c ± 0.12  0.997b ± 0.06  Nutrients  After 1 d  After 42 d  g/kg  Control  T1  T2  T3  T4  Control  T1  T2  T3  T4  Total C  270a ± 3.16  257a ± 0.83  258a ± 3.05  258.2a ± 2.03  263.2a ± 4.93  351a ± 1.20  323a ± 16.2  321a ± 2.89  315a ± 6.49  326a ± 5.53  Total N  4.97a ± 0.40  5.02a ± 0.14  5.05a ± 0.15  5.17a ± 0.62  5.84a ± 0.47  2.35a ± 0.16  6.36b ± 0.74  6.43b ± 0.94  6.13b ± 1.39  6.34b ± 0.32  Total P  1.93a ± 0.04  1.57b ± 0.06  1.777a ± 0.03  1.632b,c ± 0.02  1.657b,c ± 0.04  0.954a ± 0.02  0.72a,b ± 0.01  0.775a ± 0.007  0.838a,c ± 0.01  0.803a ± 0.01  Total K  3.097a ± 0.11  2.913a ± 0.06  3.05a ± 0.1  2.908a ± 0.04  2.94a ± 0.09  1.97a ± 0.04  1.497b ± 0.05  1.63b ± 0.04  1.685b,c ± 0.03  1.788a–c ± 0.01  Total Al  0.563a ± 0.04  5.302b ± 0.12  3.662c ± 0.07  5.232b ± 0.08  3.347c ± 0.006  0.183a ± 0.01  2.723b ± 0.04  1.926c ± 0.04  3.359d ± 0.04  2.18e ± 0.03  Total Fe  1.038a ± 0.13  20.565b ± 0.42  22.81c ± 0.38  13.183d ± 0.22  12.842d ± 0.20  0.507a ± 0.02  9.103b ± 0.14  10.231c ± 0.20  6.901d ± 0.1  7.532d ± 0.17  WS-P  1.158a ± 0.01  0.081b ± 0.004  0.078b ± 0.005  0.083b ± 0.003  0.08b ± 0.015  0.891a ± 0.05  0.094b ± 0.004  0.087b ± 0.006  0.106b ± 0.008  0.111b ± 0.007  WS-Fe  0.062a ± 0.01  2.855b ± 0.15  2.813b ± 0.02  1.535d ± 0.03  1.417d ± 0.21  0.077a ± 0.007  1.823b ± 0.06  1.869b ± 0.04  0.565c ± 0.008  0.52c ± 0.005  WS1-Al  0.071a ± 0.001  3.629b ± 0.06  1.533a ± 0.28  2.955b ± 0.62  1.425a ± 0.30  0.023a ± 0.009  2.002b ± 0.17  1.1c ± 0.03  1.508b,c ± 0.12  0.997b ± 0.06  Notes: Control (no addition); T1: 50 + 50 g/kg; T2: 25 + 50 g/kg; T3: 50 + 25 g/kg; and T4: 25 + 25 g/kg (expressed as aluminum sulfate + ferric chloride per kilogram of litter). CN and WS results are expressed on a wet weight basis, while all other values are expressed on a dry weight basis. All values are expressed as means ± SEM. a–eMeans in a row having different superscripts are significantly different (P < 0.05). 1WS: water-soluble nutrients. View Large N contents in the control, T1, T2, T3, and T4 were 4.97, 5.02, 5.05, 5.17, and 5.84 g/kg, respectively with no significant differences (P < 0.05) between the control treatment and all of the treated litters, 1 d after applying the blends and 2.35, 6.63, 6.43, 6.13, and 6.34 g/kg, respectively with significant differences (P < 0.05) between the control treatment and all of the treated litters, 42 d after applying the blends. The N content was significantly reduced in the control treatment due to the volatilization of NH3 and increased in the treated litter due to a reduction in this NH3 volatilization. The treated litters had a high N content after 42 d, with no significant difference observed between these. Other studies have also reported that the use of aluminum sulfate can increase the N content of poultry litter [33]. Furthermore, studies conducted by Sims and Luka-McCafferty [35] revealed that the average N content increased as the pH decreased, and Moore et al. [18,19] suggested that the additional N in the litter in the form of ammonium arises from low NH3 volatilization. Therefore, it is hypothesized that an aluminum sulfate/ferric chloride blend reduces the pH and NH3 volatilization and improves the N content of poultry litter. The average water-soluble P concentrations in the control, T1, T2, T3, and T4 were 1.93, 1.57, 1.77, 1.63, and 1.65 g/kg, respectively, 1 d after applying the blends and 0.88, 0.72, 0.77, 0.83, and 0.80 g/kg, respectively, 42 d after applying the blends (Table 3). Water-soluble P concentrations were also significantly reduced following the application of aluminum sulfate and ferric chloride. Though there was little difference between the treated litters after 1 d, a slight difference was observed between all treatments after 6 wk. These lower water-soluble P concentrations are consistent with the results of other studies and may be due to the formation of amorphous aluminum hydroxides when Al3+ dissociates from aluminum sulfate and hydrolyzes in alkaline litter [19]. Also Peak and Hunger revealed that alum decreases water-soluble P in poultry litter by forming insoluble AlPO4 hydroxides and Al(OH)3-phosphate surface adsorption complexes [36–37]. Our study showed that litter amendment with alum and ferric chloride blend could be considered as a key tool for reducing runoff and leaching losses of soluble nutrients. At the end of study the total phosphorus of untreated litter were higher than treated litter but in comparison with initial total phosphorus the concentration were reduce. The average total P concentrations in the control, T1, T2, T3, and T4 were 1.93, 1.57, 1.77, 1.63, and 1.65 g/kg, respectively, 1 d after applying the blends and 0.954, 0.72, 0.77, 0.83, and 0.80 g/kg, respectively, 42 d after applying the blends (Table 3). The results of our study are similar to previous laboratory studies, albeit with a lower nutrient concentration due to the lower ratio of manure to sawdust used. CONCLUSIONS AND APPLICATIONS The application of aluminum sulfate/ferric chloride blends at different concentrations greatly reduced the pH, moisture content, and NH3 volatilizations from poultry litter, with 50 + 50 and 25 + 50 g/kg concentrations of aluminum sulfate and ferric chloride, respectively, having the largest effects. A higher ferric chloride concentration (25 + 50 g/kg) in the blend was more effective than a higher aluminum sulfate concentration (50 + 25 g/kg). Various concentrations of the blend increased the N in treated litter and decreased in untreated litter and reduced the water-soluble P content of treated poultry litter. There was a clear difference in CO2 and NH3 volatilizations of the treated and control litters. However, other factors, such as time, temperature, and humidity, also affected these concentrations. Further studies are required that use different concentrations of the blend in a farm evaluation and laboratory experiment. Footnotes Primary Audience: Researchers, Agriculture Engineers, Nutritionists, Poultry Industry REFERENCES AND NOTES 1. Cabrera M L., Chiang S. C.. 1994. Water content effect on denitrification and ammonia volatilization in poultry litter. Soil Sci. Soc. Am. J.  58: 811– 816. Google Scholar CrossRef Search ADS   2. Reece F. N., Lott B. D., Deaton J W.. 1980. 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Google Scholar CrossRef Search ADS   36. Peak D., Sims J. T., Sparks D. L.. 2002. Solid-state speciation of natural and alum-amended poultry litter using XANES spectroscopy. Environ. Sci. Technol.  36: 4253– 4261 Google Scholar CrossRef Search ADS PubMed  37. Hunger S., Cho H., Sims J. T., Sparks D. L.. 2004. Direct speciation of phosphorus in alum-amended poultry litter: Solid-state 31P NMR investigation. Environ. Sci. Technol.  38: 674– 681. Google Scholar CrossRef Search ADS PubMed  Acknowledgements This research was supported by Korea Institute of Planning and Evaluation for technology in Food, Agriculture, Forestry and Fisheries (IPET) through Research Centre Support Program (Project No. 717001-7) , Ministry of Agriculture, Food and Rural affairs (MAFRA). © 2017 Poultry Science Association Inc.

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Journal of Applied Poultry ResearchOxford University Press

Published: Mar 1, 2018

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