Manure Additives Research Articles

Effect of Manure Additives Mixed with Probiotics and Zeolite on Harmful Gas Production Released From Pig Slurry

Effect of Manure Additives Mixed with Probiotics and Zeolite on Harmful Gas Production Released From Pig Slurry

Mitigation of Odor, NH3, H2S, GHG, and VOC Emissions With Current Products for Use in Deep-Pit Swine Manure Storage Structures

Odorous gas emissions from swine production have been a concern for neighbors and communities near livestock farms. Manure storage is one of the main sources of gaseous emissions. Manure additive products are marketed as a simple solution to this environmental challenge. Manure additives are user-friendly for producers and can be applied (e.g., periodically poured into manure) without changing the current manure storage structure. Little scientific data exist on how these products perform in mitigating gaseous emissions from swine manure. The research objective was to evaluate the effectiveness of 12 marketed manure additives on mitigating odor, ammonia (NH3), hydrogen sulfide (H2S), greenhouse gases (GHG), and odorous volatile organic compounds (VOCs) from stored swine manure. A controlled pilot-scale setup was used to conduct 8-week long trials using manufacturer-prescribed dosages of additives into swine manures. Manure was outsourced from three swine farms to represent a variety of manure storage types and other factors affecting the properties. Measured gaseous emissions were compared between the treated and untreated manure. None of the tested products showed a significant reduction in gaseous emissions when all (n = 3) manures were treated as replicates. Selected products showed a wide range of statistically-significant reduction and generation of gaseous emissions when emissions were compared in pairs of manure types from one farm. The latter observation highlighted the lack of consistent mitigation of gaseous emissions by manure additives. The results of this study do not warrant full-scale trials with the tested products.

Mitigation of Gaseous Emissions from Swine Manure with the Surficial Application of Biochars

Environmental impact associated with odor and gaseous emissions from animal manure is one of the challenges for communities, farmers, and regulatory agencies. Microbe-based manure additives treatments are marketed and used by farmers for mitigation of emissions. However, their performance is difficult to assess objectively. Thus, comprehensive, practical, and low-cost treatments are still in demand. We have been advancing such treatments based on physicochemical principles. The objective of this research was to test the effect of the surficial application of a thin layer (¼ inches; 6.3 mm) of biochar on the mitigation of gaseous emissions (as the percent reduction, % R) from swine manure. Two types of biochar were tested: highly alkaline and porous (HAP) biochar made from corn stover and red oak (RO), both with different pH and morphology. Three 30-day trials were conducted with a layer of HAP and RO (2.0 & 1.65 kg∙m−2, respectively) applied on manure surface, and emissions of ammonia (NH3), hydrogen sulfide (H2S), greenhouse gases (GHG), and odorous volatile organic compounds (VOCs) were measured. The manure and biochar type and properties had an impact on the mitigation effect and its duration. RO significantly reduced NH3 (19–39%) and p-cresol (66–78%). H2S was mitigated (16~23%), but not significantly for all trials. The phenolic VOCs had relatively high % R in most trials but not significantly for all trials. HAP reduced NH3 (4~21%) and H2S (2~22%), but not significantly for all trials. Significant % R for p-cresol (91~97%) and skatole (74~95%) were observed for all trials. The % R for phenol and indole ranged from (60~99%) and (29~94%) but was not significant for all trials. The impact on GHGs, isobutyric acid, and the odor was mixed with some mitigation and generation effects. However, larger-scale experiments are needed to understand how biochar properties and the dose and frequency of application can be optimized to mitigate odor and gaseous emissions from swine manure. The lessons learned can also be applicable to surficial biochar treatment of gaseous emissions from other waste and area sources.

Emissions from Swine Manure Treated with Current Products for Mitigation of Odors and Reduction of NH3, H2S, VOC, and GHG Emissions

Odor and gaseous emissions from the swine industry are of concern for the wellbeing of humans and livestock. Additives applied to the swine manure surface are popular, marketed products to solve this problem and relatively inexpensive and easy for farmers to use. There is no scientific data evaluating the effectiveness of many of these products. We evaluated 12 manure additive products that are currently being marketed on their effectiveness in mitigating odor and gaseous emissions from swine manure. We used a pilot-scale system simulating the storage of swine manure with a controlled ventilation of headspace and periodic addition of manure. This dataset contains measured concentrations and estimated emissions of target gases in manure headspace above treated and untreated swine manure. These include ammonia (NH3), hydrogen sulfide (H2S), greenhouse gases (CO2, CH4, and N2O), volatile organic compounds (VOC), and odor. The experiment to test each manure additive product lasted for two months; the measurements of NH3 and H2S were completed twice a week; others were conducted weekly. The manure for each test was collected from three different farms in central Iowa to provide the necessary variety in stored swine manure properties. This dataset is useful for further analyses of gaseous emissions from swine manure under simulated storage conditions and for performance comparison of marketed products for the mitigation of gaseous emissions. Ultimately, swine farmers, the regulatory community, and the public need to have scientific data informing decisions about the usefulness of manure additives.

Effects of Two Manure Additives on Methane Emissions from Dairy Manure.

Simple SummaryLivestock farms often store liquid manure until it can be used to fertilize crops. During anaerobic storage, the manure produces methane, which is a greenhouse gas. Many livestock farms add special chemical products to the manure that are said to control odours or increase fertilizer value. We wanted to know if these additives change the amount of methane produced. Two additives that are commonly used by farmers in many countries were tested in the laboratory. We mixed liquid dairy manure with different amounts of these products and measured the amount of methane produced over 30 to 90 days. Results were then compared to the same manure without any product. These tests were done at two temperatures, around 37 °C (a typical biodigester temperature), and 20 °C (a typical manure storage temperature). We also compared the chemical and physical properties of manure. We found that adding these products did not change the amount of methane produced, and it did not change the chemical and physical properties of the manure related to methane production. These findings suggest that farms using these products can be expected to have normal methane emissions from stored manure.Liquid manure is a significant source of methane (CH4), a greenhouse gas. Many livestock farms use manure additives for practical and agronomic purposes, but the effect on CH4 emissions is unknown. To address this gap, two lab studies were conducted, evaluating the CH4 produced from liquid dairy manure with Penergetic-g® (12 mg/L, 42 mg/L, and 420 mg/L) or AgrimestMix® (30.3 mL/L). In the first study, cellulose produced 378 mL CH4/g volatile solids (VS) at 38 °C and there was no significant difference with Penergetic-g® at 12 mg/L or 42 mg/L. At the same temperature, dairy manure produced 254 mL CH4/g VS and was not significantly different from 42 mg/L Penergetic-g®. In the second lab study, the dairy manure control produced 187 mL CH4/g VS at 37 °C and 164 mL CH4/g VS at 20 °C, and there was no significant difference with AgrimestMix (30.3 mL/L) or Penergetic-g® (420 mg/L) at either temperature. Comparisons of manure composition before and after incubation indicated that the additives had no effect on pH or VS, and small and inconsistent effects on other constituents. Overall, neither additive affected CH4 production in the lab. The results suggest that farms using these additives are likely to have normal CH4 emissions from stored manure.

Effects of SOP Lagoon Additive on Gaseous Emissions from Stored Liquid Dairy Manure

Animal manure is a source of greenhouse gas (GHG) emissions and other pollutants and nuisances such as ammonia and odors. There are several technologies to reduce emissions on animal farms including manure additives; however, few have been proven effective and easy to apply to dairy lagoon systems. The present research aimed at testing the ability of the commercial additive “SOP LAGOON” to reduce emissions of GHGs (i.e., carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O)), as well as ammonia (NH3) and odors from lagoon stored liquid manure. Emissions of GHGs, NH3 and odors were measured in the laboratory from barrels filled with 65 L of manure treated with SOP LAGOON or left untreated as a control. Manure was collected from a commercial dairy that is located in Solano County, California. Emissions of GHGs and NH3 were continuously measured for one week using flux chambers placed on top of the barrels and connected to a mobile air emissions laboratory. The effects of the untreated control, versus the two respective treatment additive doses of 30.8 and 61.6 g/m3 of manure were compared to each other. The low dose was selected based on the manufacturer recommendation and the high dose was selected by doubling the low dose. Results showed that SOP LAGOON applied at the high dose (61.6 g of SOP LAGOON per m3 of manure) versus the control greatly reduced (p < 0.05) emissions of CO2, CH4, N2O and NH3 by 14.7%, 22.7%, 45.4% and 45.9%, respectively. Furthermore, the high dose of SOP LAGOON treated samples versus the control samples showed less odor intensity (p < 0.05). There was no significant effect of the low dose of SOP LAGOON on the emissions of different gases. The HIGH dose of SOP LAGOON might decrease the number of methanogens and hydrolytic microorganisms and their excreted enzymes during manure storage. Further studies are needed to investigate the mechanism of emission reduction using SOP LAGOON.

Life cycle assessment of the use of nanomaterials in biogas production from anaerobic digestion of manure

Recently, the use of nanomaterials as biostimulators for the methanogenic bacteria has been commonly deployed. This is to maximize the biogas production from livestock manure through the anaerobic digestion processes. Yet, the environmental impact of the nanomaterials as manure additives has not been evaluated. In this respect, different nanoparticles (NPs) of nickel (Ni), cobalt (Co), iron (Fe) and iron oxide (Fe3O4) were used in biogas production to study their environmental impact using life-cycle assessment (LCA) methodology. Global warming, greenhouse gas (GHG) emissions, acidification, eutrophication, resource depletion, human toxicity potential, and ozone layer depletion potential were investigated. The results showed that Co NPs was the most effective in reducing the greenhouse gas emissions through electricity production. The greenhouse gas emissions were 0.0366, 0.0276, 0.0225, 0.0336 and 0.0290 kg CO2 eq./MJ elect. for the control, Ni NPs, Co NPs, Fe NPs and Fe3O4 NPs, respectively. Furthermore, Co NPs delivered the lowest acidification, human toxicity potential and eutrophication values. While, Ni NPs delivered the lowest resource and ozone layer depletion values.

Environmental impacts concerning the addition of trace metals in the process of biogas production from anaerobic digestion of slurry

Abstract The use of trace metals as additives to the biogas production process to increase the biogas yield has been identified as a very common approach. Such additives can biostimulate the methanogenic bacteria to increase the biogas and methane production from the anaerobic digestion (AD) of livestock manure. The environmental impact of using the trace elements as manure additives still not evaluated. The objective of this paper is to conduct a comparative environmental impact evaluation of manure treatment with different trace elements for biogas production. The trace metals under evaluation were in the form of the chlorides of nickel (Ni), cobalt (Co) and iron (Fe) which were used as additives to the anaerobic digestion of livestock manure. The results were shown in the form of the specific impacts on global warming and greenhouse gas (GHG) emissions mitigation of producing and utilizing biogas as a bioenergy source. The results of this investigation show that the use of 1 g/m3 cobalt chloride (CoCl2) causes the lowest greenhouse gas emissions among all other evaluated trace metals which were calculated on the basis of CO2-equivalent. An important observation is that the greenhouse gas emissions from the electricity generated using biogas produced without any additives, i.e. without trace metals, were the highest among all other variants/scenarios.

TEKNIK PEMBUATAN PUPUK ORGANIK DARI LIMBAH PADAT INDUSTRI MDF

Woody waste from logging activities and the wood processing industry is quite large. If this waste is not utilized, it will cause considerable losses due to wasted woody waste. In Indonesia there are many wood processing industries including the pulp and paper industry, plywood, molding, and medium density fiberboard (MDF). In the MDF industry, chipping are the activities that must be carried out. However, this chipping activity leaves considerable waste in the form of fine chips. Related to this, it is necessary to find and get the use of organic solid waste into a product that can provide added value and technology that can be applied by the communities. One solusion to this is probably by utilizing the waste into organic fertilizer. The aim of this study was to obtain information and technology for making organic fertilizers from the MDF's organic solid waste industry. Fine chip samples were taken from the MDF industry using raw materials from acacia mangium and gmelina, located in Senoni, Kutai Kartanegara Regency, East Kalimantan Province. Organic fertilizer was made by composting using EM-4 microbial consurtium with rice straw and chicken manure additives. The results of the study show that technically the composting of MDF solid waste can be done well. The composting process to mature takes about 4 months. Composting reduces the C element content of MDF waste from around 56% to 25%, and decreases the value of C/N ratio from 347 to around 28. Composting increases the N element more than 5 times, and also increases the content of K elements. Adding rice straw and chicken manure in general it tended to decrease the value of the C/N ratio, increase pH, and increase the levels of elements P, K, Ca and Mg and their cation exchange capacity. The addition of these materials generally made compost meet SNI standards except the compost water content.

Effect of Bio-Organic Additives and Mineral Nitrogen Fertilizer Rates on Nitrogen, Phosphorus and Potassium Uptake by Sorghum with Aid of 15N Stable Isotope

A pot experiment was conducted in the green house to evaluate the response of sorghum crop grown on newly reclaimed sand soil to different organic additives in combination with biofertilizer Azotobacter chroococcum and different rates of mineral-N. Straw and root dry weight was stimulated by bacterial inoculation combined with high rate of mineral fertilizer (40 mg N pot-1). Nitrogen uptake by straw and root was gradually increased with increasing fertilizer-N rates. Similar enhancement effect of organic fertilizers and bacterial inoculation was also recognized with high N rate. P uptake by plants was positively enhanced by nitrogen fertilizer application, compost and chicken manure additives. Reversibly, bacterial inoculation has no positive effect on P uptake by either straw or root. Potassium uptake was not varied as affected by organic additives. But, to some extent, it was enhanced by increasing the nitrogen fertilizer rates. Generally, bacterial inoculation has no positive effect on K uptake by either straw or root. Chicken manure was the best in releasing mineralized N (Ndforg) to inoculated plants, followed by leucaena residue then compost. In case of the un-inoculated plants, the release of N from chicken manure surpasses those of compost whereas leucaena residues came to the next. N derived from mineral fertilizer was significantly affected by mineral fertilizer rates and to some extent by organic types. Increases of %Ndff in the uninoculated plants confirmed its dependence mainly on N gained from mineral fertilizer rather than other sources like those derived from organic additives or soil.

Effects of Manure Storage Additives on Manure Composition and Greenhouse Gas and Ammonia Emissions

Storage of dairy manure slurry allows flexibility in the timing of land application of manure to reduce environmental impacts related to water quality. However, manure storage can increase greenhouse gas (GHG) and ammonia (NH 3 ) emissions and cause operational issues due to the buildup of slurry solids. To combat these negative consequences, stored manure was treated with manure additives, i.e., More than Manure (MTM), Pro-Act Biotech (Pro-Act), and biochar, to quantify their effects on manure solids, nitrogen losses, and GHG emissions in two separate trails. Gaseous emissions were studied over a 48-day manure storage period with treatments of MTM, Pro-Act, aeration and Pro-Act, aeration alone, and biochar. Manure characteristics were further examined in a 28-day manure storage study with treatments of MTM at the supplier-recommended rate, MTM at 25x the recommended rate, aeration and Pro-Act at the supplier-recommended rate, aeration and Pro-Act at 10x the recommended rate, aeration alone, and two additional Pro-Act treatments without aeration, one at the recommended rate and one at 10x that rate. Biochar was the only manure treatment to impact manure characteristics, with significantly more ammoniacal nitrogen (TAN) on day 14 than the control (p 3 emissions from the control, likely due to the 10 cm natural crust on the control. MTM increased CO 2 emissions, with significantly higher emissions on days 7 and 14 during the gaseous emissions study. Overall, no treatments were able to reduce manure solids or nitrogen emissions for these manure storage conditions.

액상 돈분에서 병원균과 가스 발생량을 감소시키기 위한 분 첨가제로서 생균제의 축산환경경영평가

Abstract This study aimed to evaluate the effects of probiotics as manure additives on pathogen, mineral, carbon dioxide and methane emissions in pig slurry as a function of time and provide information about the importance of pig slurry management to pig producers. An experiment was a completely randomized design and four treatments: CON: no treatment (5 kg pig slurry), T1: 5 kg pig slurry + 0.2% bacillus subtilis , T2: 5 kg pig slurry + 0.2% yeast, T3: 5 kg pig slurry + 0.2% actinomycetales. All treatments were replicated three times. The results information that is analyzed includes the following: First, in spite of the lack of statistically significant differences, pH values and carbon dioxide were lowered ( P < 0.05) in all probiotic treatments compared with the controls as a function of time. Second, all probiotic treatments had no effect on Salmonella enterica, mineral, and methane emission. The results of this study indicated that addition of 0.2% probiotic to pig slurry resulted in lower pH and carbon dioxide emissions, and carbon dioxide and methane emitted from pig slurry is not listed as noxious gases.

SLURRY TREATMENT WITH FOOD INDUSTRY WASTES FOR REDUCING METHANE, NITROUS OXIDE AND AMMONIA EMISSIONS

Livestock manure is the main source of ammonia (NH3) emissions and an important source of greenhouse gases (GHG) especially methane (CH4) and nitrous oxide (N2O). Ammonia emissions contribute to eutrophication and acidification of water, soils and ecosystems. The greenhouse gases contribute to the global warming. These gaseous emissions can be reduced by controlling the pH-value of manure. Acidifying the manure can reduce CH4, N2O and NH3 emissions. Inorganic acids are feasible, but have several disadvantages, e.g. soil contaminants. The use of organic acids is an efficient but expensive method; therefore using the food industry wastes which already contain organic acids is highly feasible. The objective of this research is to investigate the effects food industry wastes as manure additives on the emissions of CH4, N2O and NH3. Dairy cattle manure was treated with food industry wastes (whey and waste of citrus and orange juices industry) and the gas flux of CH4, N2O and NH3 were quantified using a specially designed gas detection system which consists of several flasks and a multi-gas monitor. The results showed that the gas fluxes emitted from manure treated with waste of citrus juice industry were 13, 0.219 and 2.523 g m-2 day-1 for CH4, N2O and NH3 respectively. The gas fluxes emitted from manure treated with waste of orange juice industry were 13.58, 0.223 and 2.581 g m-2 day-1 for CH4, N2O and NH3 respectively. The gas fluxes emitted from manure treated with whey were 17.45, 0.279 and 3.063 g m-2 day-1 for CH4, N2O and NH3 respectively. The gas fluxes emitted from the control sample (mixture of manure and water) were 58.21, 0.347 and 18.9 g m-2 day-1 for CH4, N2O and NH3 respectively. Consequently, manure treatment with food industry wastes enabled high reduction rates of gaseous emissions from manure.

Strategies to control odours in livestock facilities: a critical review

Odours generated in livestock buildings constitute one of the most relevant air quality issues of intensive livestock production. Reducing nuisance episodes related to odour exposure is therefore essential for a sustainable livestock production. In this study, the state-of-the-art on odour mitigation techniques in livestock housing is critically reviewed. Scientific advances in the last decade are revised and research needs are also identified. The complex nature of livestock odours is firstly reviewed and examined. Then, the most relevant odour control strategies are analyzed in terms of present knowledge and future needs. The strategies considered are: nutritional strategies, manure additives, building design, air filtration, manure covers, manure treatment systems and windbreaks. Finally, future research needs and priorities when establishing mitigation techniques are identified. Despite important recent advances, there are still some challenges for scientists, producers and regulators, particularly related to field evaluation of odours. Therefore, to control livestock odours effectively, using standardized field assessment techniques will be required. Also, investigating measurement and model errors may be useful to better understand the limitations of the current methods, as well as to identify research priorities.

Effects of Probiotic Additions to Feed and Manure on Temperature, Humidity, and Carbon Dioxide Emissions in Hanwoo Manure during Summer - A Field Study

Abstract The effects of probiotic additions to feed and manure on temperature, humidity and carbon dioxide (CO 2 ) emissions in Hanwoo manure during summer (4 weeks) were evaluated. Fifteen Hanwoo (24-mo-old, 580 ± 20 kg) were housed in individual pens (5 × 8 m) and randomly assigned to 1 of 3 treatments (n = 5 cattle per treatment). Hanwoo were fed experimental rations as follows: control (10 kg roughage + 2 kg concentrate); T1 (10 kg roughage + 2 kg concentrate, 2% probiotics on as-fed basis); and T2 (10 kg roughage + 2 kg concentrate, 2% probiotics on as-fed basis + 7 kg probiotics as top-dressing on the surface of Hanwoo manure). In comparison to the control, the addition of probiotics to feed or feed and manure had an effect (P < 0.05) on temperature and humidity over the 4 weeks, except for humidity at 0 weeks. The only significant difference (P < 0.05) observed in CO 2 emission was among all treatments at 3 and 4 weeks (but not at 0 through 2 weeks). These results indicated that use of probiotics as feed and manure additives did not have a significant effect on environmental parameters.

Simulation of Long-Term Carbon and Nitrogen Dynamics in Grassland-Based Dairy Farming Systems to Evaluate Mitigation Strategies for Nutrient Losses

Many measures have been proposed to mitigate gaseous emissions and other nutrient losses from agroecosystems, which can have large detrimental effects for the quality of soils, water and air, and contribute to eutrophication and global warming. Due to complexities in farm management, biological interactions and emission measurements, most experiments focus on analysis of short-term effects of isolated mitigation practices. Here we present a model that allows simulating long-term effects at the whole-farm level of combined measures related to grassland management, animal housing and manure handling after excretion, during storage and after field application. The model describes the dynamics of pools of organic carbon and nitrogen (N), and of inorganic N, as affected by farm management in grassland-based dairy systems. We assessed the long-term effects of delayed grass mowing, housing type (cubicle and sloping floor barns, resulting in production of slurry and solid cattle manure, respectively), manure additives, contrasting manure storage methods and irrigation after application of covered manure. Simulations demonstrated that individually applied practices often result in compensatory loss pathways. For instance, methods to reduce ammonia emissions during storage like roofing or covering of manure led to larger losses through ammonia volatilization, nitrate leaching or denitrification after application, unless extra measures like irrigation were used. A strategy of combined management practices of delayed mowing and fertilization with solid cattle manure that is treated with zeolite, stored under an impermeable sheet and irrigated after application was effective to increase soil carbon stocks, increase feed self-sufficiency and reduce losses by ammonia volatilization and soil N losses. Although long-term datasets (>25 years) of farm nutrient dynamics and loss flows are not available to validate the model, the model is firmly based on knowledge of processes and measured effects of individual practices, and allows the integrated exploration of effective emission mitigation strategies.

사료와 축분에 생균제 첨가 시 한우분 내 질소와 수용성인의 함량 변화: 현장연구 중심으로

This study was conducted to investigate the changes in nitrogen and soluble reactive phosphorus(SRP) contents from hanwoo manure using probiotics to feed and manure additives during 5 weeks. A total of 45 hanwoo(24 months old) with averaging <TEX>$580{\pm}20$</TEX> kg in weight were randomly assigned to 3 dietary treatments with 3 replicates per treatment(5 hanwoo per pen, <TEX>$5{\times}8m$</TEX>). The treatment were supplemented, control, T1(10 kg roughage + 2 kg concentrate(2% probiotics as-fed basis)), and T2(10 kg roughage + 2 kg concentrate(2% probiotics as-fed basis) + 7 kg probiotics on the surface of hanwoo manure (top-dressing)). During the experimental period, there were statistically significant differences(P<0.05) in pH values at 3 and 5 weeks; TN contents at 5 weeks; and SRP contents at 5 weeks in all treatments. Adding probiotics to feed or feed and manure increased manure pH in comparison with controls. As time increased, changes in TN contents decreased in the order: T2 > Control > T1. Especially, the reduction in SRP contents in all treatments at 5 weeks was in following order: T1 > T2 > Control. This result suggests that it is possible to make efficient use of probiotics as feed and manure additives for reducing environmental pollution or to provide fundamental information on livestock managements to producers.

Dairy Manure Compost Quality Effects On Corn Silage and Soil Properties

Soil nutrients in dairy manure composts vary depending on the original manure or other additives, with consequent effects on crop production. An experiment addressing the effects of single applications of dairy compost of high quality (HQC) or low quality (LQC) at the incorporation rates of 0, 45, and 90 Mg ha−1 on corn (Zea mays L.) silage yields, forage quality, and soil nutrients was conducted in 2004 and 2005. The composts were incorporated prior to planting in 2004, which were also compared with the performance of two commercial fertilizer levels (N-P-K) at high (HIF, 336-98-93) or low rates (LIF, 168-49-47). Compost treatment plots received annual split applications of supplemental inorganic N at 224 or 336 kg ha−1. Through the two growing seasons, corn silage yields ranged from 17 to 25 Mg ha−1 yr−1 depending on compost quality and compost application rates. Corn silage yields in plots with HQC were generally greater than LQC in 2004, but yields did not differ in 2005. Total apparent N recovery did not differ between compost qualities or among compost rates. Soil pH of LQC treatments averaged 8.1 after the second season and remained higher than that of HQC which ranged from 7.4 to 7.6. Electrical conductivity (EC) of soils from HQC plots was 14% lower than that of LQC in 2004 and became similar to that of LQC in 2005. Soil P and K levels in LQC were greater than HQC and were greatest in the 90 Mg ha−1 rate. Based on these data, there is no advantage of using the higher quality compost with greater OM.

Volatilization of ammonia from manure as affected by manure additives, temperature and mixing

Ammonia (NH 3) volatilization decreases the N-nutrient value of livestock manure slurries and can lead to soil acidification and eutrophication problems. In this study the effect of three manure additives (Euro Mest-mix ® (Mx), Effective Micro-organisms ® (EM), and Agri-mest ® (Am)) on NH 3 volatilization at three temperatures (4, 20, and 35 °C) was investigated. The manufacturers claim that Mx contains absorbing clay minerals and that applying Am and EM to slurry will reduce nitrogen losses, most likely by enhancing the biodegradation of manure slurry. Furthermore, the effect of mixing slurry on NH 3 volatilization has been investigated. Ammonia volatilization increased with increasing temperature and mixing of the slurries. However, at 35 °C mixing of manure reduced NH 3 emissions compared to non-mixing, which is related to a reduced crust resistance to gaseous transport at higher temperatures for non-mixing. Moreover, mixing introduces oxygen into the anaerobic slurry environment which will slow down microbial activity. The use of additives did not change manure characteristics (pH, dry matter, N total, N mineral, C/N, and C/N organic) and did not result in a significant ( p < 0.05) decrease in NH 3 emissions, except that at 4 °C and no mixing a significant decrease of 34% in NH 3 volatilization was observed, when Am and EM together, were applied to slurry.

EFFECT OF MICROBIAL ADDITIVES COMBINED WITH AERATION ON REDUCTION OF NUTRIENTS IN SWINE MANURE

The research presented in this article evaluated a technique using manure additives (Sporzyme and activated sludge) coupled with aeration treatment in reducing nutrients from liquid swine manure. Plastic columns, 91.6 cm in height and 15.3 cm in internal diameter, were each filled with 15 L liquid swine manure. Aeration was provided to each column by an air pump at an airflow rate of 2.0 L/min, controlled by individual airflow meters mounted on the columns. The experiment included five treatments: (1) control (no aeration and no additives), (2) aeration alone, (3) aeration with a microbial additive (Sporzyme), (4) aeration with activated sludge inoculum without anaerobic incubation prior to aeration, and (5) aeration with activated sludge inoculum with three days of anaerobic incubation prior to aeration. The results indicated that total Kjeldahl nitrogen (TKN), ammonia-N, and total soluble phosphorus were reduced by about 42%, 56%, and 72%, respectively, by all the treatments except the control. The reduction of TKN was found to be mainly attributed to the reduction of ammonia because its share of TKN was remarkably reduced at the end of the test. Although Sporzyme significantly increases the aerobic count in the manure, data from this study have showed no advantage of its use (or the activated sludge as seeding) solely for enhancing nutrient reduction in swine manure under aeration treatment since there was little difference found in terms of either nitrogen or phosphorus reduction between treatments with and without additives.