DOI: 10.5061/dryad.tht76hf5z
title: Soil nitrous oxide emissions from global specialty crop systems

description: The data were extracted from published studies. All references and data
 sources are listed.   We conducted an exhaustive
 literature search using Google Scholar and Web of Science databases. The
 searched keywords were ‘soil nitrous oxide emission’, ‘soil greenhouse gas
 emission’, and ‘soil trace gas emission’ respectively combined with each
 specialty crop. We searched for the common specialty crops listed by USDA,
 including fruits, tree nuts, and vegetables
 (https://www.ams.usda.gov/services/grants/scbgp/specialty-crop). The most
 recent search was in November 2023. For each article returned by the
 search, we evaluated whether it reported field observations of annual
 cumulative N2O emissions. Laboratory and greenhouse studies were excluded.
 This process identified 1137 observations from 114 studies. These studies
 covered six continents and four main climate types (Köppen climate
 classification). Area-scaled N2O emissions were reported as annual
 cumulative emissions (kg N2O-N ha−1 year−1).  Yield-scaled N2O
 emissions were calculated by dividing area-scaled N2O emissions by fresh
 weight yield (kg N2O-N Mg fresh yield−1). The emission factor
 (EF) for annual cumulative N2O emission was calculated by EF (%) = (EN −
 E0)/Nrate. The EN and E0 are the N2O emissions (kg N2O-N ha−1 year−1) with
 and without N fertilizer, respectively. The Nrate is the N fertilizer
 application rate (kg N ha−1 year−1). Soil properties and environmental
 factors were also listed if they were avalable. Empty cells in the
 datasheet indicate no data avalable for that category or variable.
description: # Soil nitrous oxide emissions from global specialty crop systems
 Soil nitrous oxide
 emissions from global specialty crop systems were collected, with 1137
 observations from 114 published studies. ## Description of the data and
 file structure Area-scaled N2O emissions were reported as annual
 cumulative emissions (kg N2O-N ha−1 year−1).  Yield-scaled N2O emissions
 were calculated by dividing area-scaled N2O emissions by fresh weight
 yield (kg N2O-N Mg fresh yield−1). The emission factor (EF) for annual
 cumulative N2O emission was calculated by EF (%) = (EN − E0)/Nrate. The EN
 and E0 are the N2O emissions (kg N2O-N ha−1 year−1) with and without N
 fertilizer, respectively. The Nrate is the N fertilizer application rate
 (kg N ha−1 year−1). Fertilizer rate was reported as annual application
 rate (kg N ha−1 year−1). The other agricultural management practices,
 e.g., irrigation, tillage, cover crop, biochar, were also reported if they
 were available in the published studies. Climatic factors, e.g., climate
 type, mean annual temperature, mean annual precipitation, were reported.
 Soil properties, e.g., soil organic carbon (SOC), soil pH, soil texture,
 were reported. References and data sources were listed. Empty cells in the
 datasheet indicate no data available for that category. | Variables and
 Definitions | |
 :-------------------------------------------------------------------------------------- | | Counts, total number of observations | | Annual cumulative N2O-N (kg ha−1 year−1), soil N2O emissions per year | | Annual crop yield (fresh weight Mg ha−1 year−1), crop yield per year | | Yield-scaled N2O-N (kg N Mg yield−1), Annual cumulative N2O-N divided Annual crop yield | | Fertilizer rate kg N ha−1 year−1, nitrogen fertilizer application rate per year | | Emission factor (%), N2O emission factor | | Fertilizer type, organic, inorganic, or organic+inorganic | | Nitrification inhibitor, yes or no | | Fertigation, yes or no | | Irrigation rate, full or deficit irrigation | | Irrigation type, drip irrigation or other | | Rotation number per year, 1-3 rotations per year | | Tillage, conventional or reduced tillage | | Cover crop, legume, non-legume, or no cover crop | | Biochar, yes or no | | Köppen-Geiger climate classification, climate type of the study location | | Mean annual temperature (°C), Mean annual temperature of the study location | | Mean annual precipitation (mm), Mean annual precipitation of the study location | | Water regime, rainfed or irrigated | | SOC (%), soil organic carbon concentration | | Soil texture, coarse, medium, or fine | | Soil pH, the pH value of the soil | | Crop type, annual or perennial | | Crop, the specific crop in the study field | | Latitude, latitude of the study location | | Longitude, Longitude of the study location | | Site, study location | | Continent, study location | | Reference, data source | ## Sharing/Access information n/a ## Code/Software n/a