• Energy Research

The contribution of animal waste storage on GHG emissions and climate change is a serious issue for agriculture. The carbon emissions that are generated from barns represent a relevant source of emissions that negatively affect the environmental performance measures of livestock production. In this experiment, CO2 and CH4 emissions from different animal wastes, namely, digestate, slurry, and manure, were evaluated both in their original form and with a biochar addition. The emissions were monitored using the static camber methodology and a portable gas analyzer for a 21-day period. The addition of biochar (at a ratio of 2:1 between the substrates and biochar) significantly reduced the emissions of both gases compared to the untreated substrates. Slurry exhibited higher emissions due to its elevated gas emission tendency. The biochar addition reduced CO2 and CH4 emissions by 26% and 21%, respectively, from the slurry. The main effect of the biochar addition was on the digestate, where the emissions decreased by 45% for CO2 and 78% for CH4. Despite a lower tendency to emit carbon-based gases of manure, biochar addition still caused relevant decreases in CO2 (40%) and CH4 (81%) emissions. Biochar reduced the environmental impacts of all treatments, with a GWP reduction of 55% for the digestate, 22% for the slurry, and 44% for the manure.

AbstractResearch in global change ecology relies heavily on global climatic grids derived from estimates of air temperature in open areas at around 2 m above the ground. These climatic grids do not reflect conditions below vegetation canopies and near the ground surface, where critical ecosystem functions occur and most terrestrial species reside. Here, we provide global maps of soil temperature and bioclimatic variables at a 1‐km2resolution for 0–5 and 5–15 cm soil depth. These maps were created by calculating the difference (i.e. offset) between in situ soil temperature measurements, based on time series from over 1200 1‐km2pixels (summarized from 8519 unique temperature sensors) across all the world's major terrestrial biomes, and coarse‐grained air temperature estimates from ERA5‐Land (an atmospheric reanalysis by the European Centre for Medium‐Range Weather Forecasts). We show that mean annual soil temperature differs markedly from the corresponding gridded air temperature, by up to 10°C (mean = 3.0 ± 2.1°C), with substantial variation across biomes and seasons. Over the year, soils in cold and/or dry biomes are substantially warmer (+3.6 ± 2.3°C) than gridded air temperature, whereas soils in warm and humid environments are on average slightly cooler (−0.7 ± 2.3°C). The observed substantial and biome‐specific offsets emphasize that the projected impacts of climate and climate change on near‐surface biodiversity and ecosystem functioning are inaccurately assessed when air rather than soil temperature is used, especially in cold environments. The global soil‐related bioclimatic variables provided here are an important step forward for any application in ecology and related disciplines. Nevertheless, we highlight the need to fill remaining geographic gaps by collecting more in situ measurements of microclimate conditions to further enhance the spatiotemporal resolution of global soil temperature products for ecological applications.