Effects of Turning Frequency on Ammonia Emission during the Composting of Chicken Manure and Soybean Straw

Here, we investigated the impact of different turning frequency (TF) on dynamic changes of N fractions, NH3 emission and bacterial/archaeal community during chicken manure composting. Compared to higher TF (i.e., turning every 1 or 3 days in CMS1 or CMS3 treatments, respectively), lower TF (i.e., turning every 5 or 7 days in CMS5 or CMS7 treatments, respectively) decreased NH3 emission by 11.42–18.95%. Compared with CMS1, CMS3 and CMS7 treatments, the total nitrogen loss of CMS5 decreased by 38.03%, 17.06% and 24.76%, respectively. Ammonia oxidizing bacterial/archaeal (AOB/AOA) communities analysis revealed that the relative abundance of Nitrosospira and Nitrososphaera was higher in lower TF treatment during the thermophilic and cooling stages, which could contribute to the reduction of NH3 emission. Thus, different TF had a great influence on NH3 emission and microbial community during composting. It is practically feasible to increase the abundance of AOB/AOA through adjusting TF and reduce NH3 emission the loss of nitrogen during chicken manure composting.

Ammonia Emission in Various Star-forming Environments: A Pilot Study of Planck Galactic Cold Clumps

The Planck Catalogue of Galactic Cold Clumps provides an all-sky sample of potential star-forming regions based on the submillimeter emission of their dust content. Around 1000 of these Planck objects were mapped with the James Clerk Maxwell telescope in the submillimeter range during the SCOPE survey, identifying prestellar and protostellar dense clumps inside them. We used the Effelsberg 100 m telescope to observe the emission lines of the NH3 inversion transitions toward a sample of 97 dense objects in varying environments in order to assess the physical parameters of their gas content. We derive their temperature, density, and velocity dispersion, correlating the resulting parameters with the environmental and evolutionary characteristics of the targets and with regard to their distance and physical size. We examine the dependence of physical parameters on distance and Galactic position and compare the gas-based and dust-continuum-based temperatures and densities. Together with the presence of maser emission and higher inversion transitions of ammonia, we may differentiate between certain groups of targets, e.g., filamentary, protostellar clumps, and high-latitude, core-sized, starless sources.

Isolation and Characterization of Effective Bacteria That Reduce Ammonia Emission from Livestock Manure

Ammonia from livestock manure reacts with chemical components discharged from various emission sources to produce airborne particulate matter. This study aimed to investigate a novel effective microbial agent to suppress ammonia gas emitted from manure. Both isolated L12I and 12III strains, identified as Pediococcus acidilactici (PA), were selected for their superior activity in assays performed with the evaluation criteria such as acid production, ammonia decomposition, and urease inhibition, which are key factors influencing ammonia excretion. The survivability of PA strains was confirmed by an increase in DNA abundance in the manure. PA strains lowered the pH of manure and suppressed the growth of hyper-ammonia-producing bacteria (HAB) possessing urease activity. The L12I and 12III treatment groups showed 23.58% and 38.00% emission reductions, respectively. Especially, the 12III strain was proven to be the more effective strain for reducing ammonia gas emission, with the best ability to reduce pH and inhibit HAB. The strains could have an additive effect in improving the manure quality as a nitrogen fertilizer by preserving the total nitrogen and urea content. These results suggest that PA strains can be used as unprecedented microbial agents to improve manure-derived environmental pollution and improve fertilizer quality.

Agronomic Weights of Ammonia Emission from Staple Crops in China as Response to Mitigation Strategies under Various Agronomic Conditions: A Meta-Analysis Study

Economic losses and environmental hazards are meaningful problems of emitted ammonia induced by extensive use of synthetic nitrogen fertilizers. The concept presented as yield scaled fertilizer productivity (YSFP) in our meta-analysis in addition to nitrogen use efficiency (NUE), nitrogen agronomic efficiency (NAE), and productivity of applied nitrogen (PAN) were used to weight ammonia emission (AV)-induced reductions in wheat, maize, and rice production. The comprehensive meta-analysis was used to weight the reductions in these parameters by AV as the difference between observed means of the collected studies and their adjusted means using AV factor. There were higher reductions in agronomic production induced by AV in rice than maize and wheat. AV-induced reductions in PAN of rice, maize, and wheat were decreased by 4.99, 3.71, and 2.42 (kg grains kg−1 N), respectively. YSFP and PAN recorded the highest sensitivity to AV in wheat (R2 = 0.88 for both) and rice (R2 = 0.92 and 0.89, respectively), while NUE was the most efficient parameter in weighting AV agronomic effects (R2 = 0.81). Slow-released N fertilizers resulted in the lowest reductions in AV agronomic parameters followed by organic amendments and then urea while using other synthetic fertilizers recorded the highest reductions by 3.90, 6.40, 1.41, and 4.70 in YSFP, NUE, NAE, and PAN, respectively. Inhibitors had the highest effect on mitigating AV agronomic losses compared with biochar and mulching and affected the parameters following that order as percentages of no amendments, YSFP (52.63%) > PAN (47.18%) > NUE (40.83%) > NAE (38.75%). This study outlines the reductions in agronomic production induced by AV and weights the efficiency of various mitigation strategies under various agronomic conditions. The results proved the efficiency of YSFP with NUE parameters to weight the effect of AV on crop yield, while suggesting to find out more applicable parameters in further studies.

Diet optimization for dairy cows to reduce ammonia emissions

Feeding livestock a balanced diet with a differentiated crude protein (CP) content, depending on the lactation phase can reduce nitrogen emissions from livestock excrement and urine. A higher content of non-starch polysaccharides in livestock diets improves feed absorption in the livestock body and, consequently, nitrogen is emitted more from protein present in livestock manure than from urea acid present in livestock urine. The aim of the study is to calculate the ammonia emission reduction potential in Latvia by optimizing the feeding of dairy cows and ensuring life longevity, as well as provide justification for ammonia emission reduction in dairy farms. Calculations made by using the NorFor Model for optimization of dairy cow (Bos primigenius f. taurus) diets revealed that compared with lowyielding cows, a higher CP content diet fed to high-yielding cows at the beginning of lactation increased the amount of nitrogen (N) in their excrement and urine by 90–180 g d-1. Reducing the CP content in the cow diet by an average of 10 g kg-1 dry matter (DM) during mid-lactation resulted in the same trend. Reducing the CP content in the cow diet during late lactation and the dry period by another 20–30 g kg-1 of DM, N emissions from excrement and urine significantly decreased. Increasing the lifespan of dairy cows also means reducing ammonia emissions from the farm. By increasing the number of lactations per cow on dairy farm, it is possible to reduce the number of heifers per cow. The total reduction of ammonia emissions in Latvia was calculated based on a long-term projection of a decrease of 0.1 heifer per dairy cow. Ammonia emissions could be reduced by 0.051 kt by decreasing the number of heifers by 12.54 thou. at the planned increase in the lifespan of dairy cows by 2030.

Achyranthes Japonica Nakai root extract supplementation improves apparent nutrient digestibility, caecum microbiota, and excreta gas emission in broiler chicks

This study investigated the effects of supplementing Achyranthes Japonica Nakai (AJN) root extract to the diet of broiler chicks on growth performance, nutrient digestibility, caecum microbiota, excreta gas emission, and relative weight of organs. A total of 270 1-day-old Ross 308 broiler chicks (42.11 ± 0.18 g) were randomly allotted into 3 dietary treatments according to the initial body weight. Each treatment had 5 replicate cages with 18 birds per cage. The experimental period was 35 days (starter, days 1-7; grower, days 8-21; finisher, days 22-35). Dietary treatments were corn-soybean meal-based basal diet supplemented with 0.000, 0.015, or 0.030 % AJN root extract. The apparent total tract digestibility of nitrogen (P = 0.025) increased linearly with the increase of the dosage of AJN root extract, while the counts of E. coli in caecum (P = 0.038) and excreta ammonia emission (P = 0.003) decreased linearly. However, the growth performance (P > 0.05) and the relative weight of organs (P > 0.05) did not differ among the dietary groups. In conclusion, AJN root extract could increase the nutrient digestibility and reduce the noxious gas emission by reducing the caecum harmful microbiota in a dose-dependent manner.

Field Quantification of Ammonia Emission following Fertilization of Golf Course Turfgrass in Sub/Urban Areas

Low cost and favorable handling characteristics make urea (46-0-0) a leading nitrogen source for frequent, foliar N fertilization of golf course putting greens in season. Yet few field investigations of resulting NH3 volatilization from putting greens have been directed. Meanwhile, NH3 emissions degrade air and surface water quality. Our objective was to quantify NH3 volatilization following practical, low-N rate, and foliar application of commercial urea-N fertilizers. Over the 2019 and 2020 growing seasons in University Park, PA, USA, an industrial vacuum pump, H3BO3 scrubbing flasks, and sixteen dynamic flux chambers were employed in four unique experiments to measure NH3 volatilization from creeping bentgrass putting greens (Agrostis stolonifera L. ‘Penn G2’) in the 24 h period ensuing foliar application of urea based-N at a 7.32 or 9.76 kg/ha rate. Simultaneous and replicated flux chamber trapping efficiency trials showing 35% mean NH3 recovery were used to adjust NH3 volatilization rates from treated plots. Under the duration and conditions described, 3.1 to 8.0% of conventional urea N volatilized from the putting greens as NH3. Conversely, 0.7 to 1.1% of methylol urea liquid fertilizer (60% short-chain methylene urea) or 0.7 to 2.2% of urea complimented with dicyandiamide (DCD) and N-(n-butyl) thiophosphoric triamide (NBPT) volatilized as NH3.