Ammonia and nitrous oxide emission factors for excreta deposited by livestock and land‐applied manure

Abstract

Manure application to land and deposition of urine and dung by grazing animals are major sources of ammonia (NH3) and nitrous oxide (N2O) emissions. Using data on NH3 and N2O emissions following land‐applied manures and excreta deposited during grazing, emission factors (EFs) disaggregated by climate zone were developed, and the effects of mitigation strategies were evaluated. The NH3 data represent emissions from cattle and swine manures in temperate wet climates, and the N2O data include cattle, sheep, and swine manure emissions in temperate wet/dry and tropical wet/dry climates. The NH3 EFs for broadcast cattle solid manure and slurry were 0.03 and 0.24 kg NH3–N kg–1 total N (TN), respectively, whereas the NH3 EF of broadcast swine slurry was 0.29. Emissions from both cattle and swine slurry were reduced between 46 and 62% with low‐emissions application methods. Land application of cattle and swine manure in wet climates had EFs of 0.005 and 0.011 kg N2O–N kg–1 TN, respectively, whereas in dry climates the EF for cattle manure was 0.0031. The N2O EFs for cattle urine and dung in wet climates were 0.0095 and 0.002 kg N2O–N kg–1 TN, respectively, which were three times greater than for dry climates. The N2O EFs for sheep urine and dung in wet climates were 0.0043 and 0.0005, respectively. The use of nitrification inhibitors reduced emissions in swine manure, cattle urine/dung, and sheep urine by 45–63%. These enhanced EFs can improve national inventories; however, more data from poorly represented regions (e.g., Asia, Africa, South America) are needed.

Global nitrous oxide emissions from livestock manure during 1890–2020: An IPCC tier 2 inventory

“…It is pertinent to note that the livestock distribution within countries may have shifted somewhat over the study period. Lastly, certain emission factors, such as the EF 3PRP , may exhibit significant spatial heterogeneity (IPCC, 2019; Luo et al., 2013; Mancia et al., 2022; van der Weerden et al., 2023). However, in this study, we did not undertake a more nuanced spatial differentiation and instead relied on global or regional averages for estimation purposes, potentially introducing added uncertainty.…”

“…Livestock manure, be it in manure management systems, left on pasture, or applied to soils, is one of the main anthropogenic sources of global N 2 O emissions (FAO, 2023b; Gerber et al., 2013; IPCC, 2006, 2019). Detecting the changes in N 2 O emissions from livestock manure is thus crucial for understanding the rise in global atmospheric N 2 O concentration, intending to identify hotspots and opportunities to optimize climate mitigation strategies in agrifood systems (Cheng et al., 2022; Herrero et al., 2016; Liu et al., 2023; Tubiello et al., 2022; van der Weerden et al., 2023; Winiwarter et al., 2018).…”

Representative Survey for Evaluating Housing and Manure Handling Technologies of the Hungarian Pig Sector

“…Replacement gilts rotation = 365 days of replacement gilts period (17) DAN of replacement gilts = Total number of replacement gilts days of replacement gilts period (18) Total number of weaner = annual number of farrowings * number of litters at farrowing − mortality at farrowing unit (19) DAN of weaners = total number of weaners weaner rotation − half of the mortality at weaners unit (20) Total number of growers = total number of weaners − total number of sold weaners − mortality at weaners unit (21) Total number of sold fattener = Total number of growers − mortality at fattener unit…”

“…Such tools are already available to farmers in many countries around the world to help them understand the key drivers of ammonia emissions and plan effective mitigation measures. Examples include DATAMAN-emissions and emission factor databases [19][20][21][22]; the National Air Quality Site Assessment Tool [23]; the Air Management Practices Assessment Tool (AMPAT) [24,25]; the Feedlot Air Emissions Treatment Cost Calculator [26]; the Spreadsheet Decision Tools [27]; the Ammonia Emissions Estimator [28]; the Ammonia Losses from Liquid Manure Applications Calculator [29]; the Dairy Gas Emission Model [30]; SCAIL-Agriculture [31]; BAT-Tool Plus [32]; the Greenhouse Gas and Ammonia Emission Reduction Calculation Tool [33]; a calculation tool for ammonia emissions in the agricultural sector (SCENA) [34]; and Agrammon [35].…”

Managing organic resources in agriculture: future challenges from a scientific perspective

“…Management measures focus on the efficient use of nutrients and C, by incorporating composition, plant-availability, C stability, and risk of nutrients losses in fertilization strategies. Technological measures to reduce nutrient emissions include changes in livestock housing systems and manure storage, the use of manure treatment techniques, and the use of precision and low emission application techniques of manures (Chadwick, 2005;Hou et al, 2015;Bougouin et al, 2016;Jensen et al, 2020;Van der Weerden et al, 2021). Structural changes in agriculture, such as the reduction or reallocation of livestock numbers, are also options to improve nutrient and C management and reduce emissions from organic resources (Van Grinsven et al, 2018;Kim et al, 2023).…”