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.

Nitrous oxide (N₂O), ammonia (NH₃), and methane (CH₄) emissions from the manure management chain of livestock production systems are important contributors to greenhouse gases (GHGs) and NH₃ emitted by human activities. Several studies have evaluated manure‐related emissions and associated key variables at regional, national, or continental scales. However, there have been few studies focusing on the drivers of these emissions using a global dataset. An international project was created (DATAMAN) to develop a global database on GHG and NH₃ emissions from the manure management chain (housing, storage, and field) to identify key variables influencing emissions and ultimately to refine emission factors (EFs) for future national GHG inventories and NH₃ emission reporting. This paper describes the “field” database that focuses on N₂O and NH₃ EFs from land‐applied manure and excreta deposited by grazing livestock. We collated relevant information (EFs, manure characteristics, soil properties, and climatic conditions) from published peer‐reviewed research, conference papers, and existing databases. The database, containing 5,632 observations compiled from 184 studies, was relatively evenly split between N₂O and NH₃ (56 and 44% of the EF values, respectively). The N₂O data were derived from studies conducted in 21 countries on five continents, with New Zealand, the United Kingdom, Kenya, and Brazil representing 86% of the data. The NH₃ data originated from studies conducted in 17 countries on four continents, with the United Kingdom, Denmark, Canada, and The Netherlands representing 79% of the data. Wet temperate climates represented 90% of the total database. The DATAMAN field database is available at http://www.dataman.co.nz.

Livestock manure management systems can be significant sources of nitrous oxide (N₂O), methane (CH₄), and ammonia (NH₃) emissions. Many studies have been conducted to improve our understanding of the emission processes and to identify influential variables in order to develop mitigation techniques adapted to each manure management step (animal housing, outdoor storage, and manure spreading to land). The international project DATAMAN (http://www.dataman.co.nz) aims to develop a global database on greenhouse gases (N₂O, CH₄) and NH₃ emissions from the manure management chain to refine emission factors (EFs) for national greenhouse gas and NH₃ inventories. This paper describes the housing and outdoor storage components of this database. Relevant information for different animal categories, manure types, livestock buildings, outdoor storage, and climatic conditions was collated from published peer reviewed research, conference papers, and existing databases published between 1995 and 2021. In the housing database, 2024 EFs were collated (63% for NH₃, 19.5% for CH₄, and 17.5% for N₂O). The storage database contains 654 NH₃ EFs from 16 countries, 243 CH₄ EFs from 13 countries, and 421 N₂O EFs from 17 countries. Across all gases, dairy cattle and swine production in temperate climate zones are the most represented animal and climate categories. As for the housing database, the number of EFs for the tropical climate zone is under‐represented. The DATAMAN database can be used for the refinement of national inventories and better assessment of the cost‐effectiveness of a range of mitigation strategies.

Details regarding the fate ofMycobacterium aviumsubsp.paratuberculosis(basonym,Mycobacterium paratuberculosis) after manure application on grassland are unknown. To evaluate this, intact soil columns were collected in plastic pipes (lysimeters) and placed under controlled conditions to test the effect of a loamy or sandy soil composition and the amount of rainfall on the fate ofM. paratuberculosisapplied to the soil surface with manure slurry. The experiment was organized as a randomized design with two factors and three replicates.M. paratuberculosis-contaminated manure was spread on the top of the 90-cm soil columns. After weekly simulated rainfall applications, water drainage samples (leachates) were collected from the base of each lysimeter and cultured forM. paratuberculosisusing Bactec MGIT ParaTB medium and supplements. Grass was harvested, quantified, and tested from each lysimeter soil surface. The identity of all probableM. paratuberculosisisolates was confirmed by PCR for IS900and F57 genetic elements. There was a lag time of 2 months after each treatment beforeM. paratuberculosiswas found in leachates. The greatest proportions ofM. paratuberculosis-positive leachates were from sandy-soil lysimeters in the manure-treated group receiving the equivalent of 1,000 mm annual rainfall. Under the higher rainfall regimen (2,000 mm/year),M. paratuberculosiswas detected more often from lysimeters with loamy soil than sandy soil. Among all lysimeters,M. paratuberculosiswas detected more often in grass clippings than in lysimeter leachates. At the end of the trial, lysimeters were disassembled and soil cultured at different depths, and we found thatM. paratuberculosiswas recovered only from the uppermost levels of the soil columns in the treated group. Factors associated withM. paratuberculosispresence in leachates were soil type and soil pH (P< 0.05). ForM. paratuberculosispresence in grass clippings, only manure application showed a significant association (P< 0.05). From these findings we conclude that this pathogen tends to move slowly through soils (faster through sandy soil) and tends to remain on grass and in the upper layers of pasture soil, representing a clear infection hazard for grazing livestock and a potential for the contamination of runoff after heavy rains.