Quantifying nitrogen deposition inputs to cropland: A national scale dataset from 1961 to 2020

Nitrogen (N) deposition is one of the major inputs to cropland and consequently important for the estimation of N Use Efficiency (NUE) for crop production. However, the estimates for N deposition carry large uncertainty, and existing assessments of N budgets and NUE on agricultural land use different estimates of N deposition. To evaluate the uncertainties in existing methods for national scale N deposition estimation and assess their impacts on the resulting NUE estimation for countries around the world, we 1) reviewed existing methods and related data sources for quantifying N deposition inputs to crop production on a national scale; 2) identified the most up–to–date data sources and designed methods to quantify N deposition input to crop production on a national scale; 3) collected N deposition data from observation sites in major countries (e.g., UK, US, and China) to validate the estimated N deposition input; and 4) conducted sensitivity analysis to evaluate how the uncertainties i..., , , , # Quantifying nitrogen deposition inputs to cropland: A national scale dataset from 1961 to 2020

Dataset DOI: [10.5061/dryad.msbcc2g1x](10.5061/dryad.msbcc2g1x)

## Description of the data and file structure

The data contain N deposition (kg N ha-1 yr-1)  in cropland. Each file has rows for countries and columns for years. The NaN stands for \"Not a Number\".

### Files and variables

#### File: 1_AH.xlsx

**Description:** includes the nitrogen deposition (kg N ha-1 yr-1) data at country scale using ACCMIP N deposition maps and HYDE 3.2 cropland maps. 

#### File: 2_AL.xlsx

**Description:** includes the nitrogen deposition (kg N ha-1 yr-1) data at country scale using ACCMIP N deposition maps and LUH2 cropland maps. 

#### File: 3_WH_update2022.xlsx

**Description:** includes the nitrogen deposition (kg N ha-1 yr-1) data at country scale using Wang et al. N deposition maps and HYDE 3.3 cropland maps. 

#### File: 4_WL_update2022.xlsx

**Description:** includes the nitrogen deposition (k..., **Changes after Oct 5, 2022:** The WH and WL data products are extended to 2022 while AL and AH are until 2020. 

Previously, we used Wang et al. as N deposition map for FAO dataset, and croplands include LUH2 and HYDE3.2 maps. As a final dataset in the previous version, LUH2 and Wang et al combination was preferred because *“(1) the Wang et al. estimates are closer to the remaining existing datasets for the majority of regions, particularly Asian countries, whereas the estimates obtained using ACCMIP are on the lower side of the distribution of N deposition compared to other datasets, with minimal change after 2005, (2) the LUH2 cropland map is available at an annual time scale, which serves the purpose of this study, while the HYDE map is only available at a decadal scale until 2000, and annually from 2000–2017, and (3) the WL product was within the range of ground estimates of N deposition from the station networks in multiple countries (i.e., China, the UK, the USA, and Ea...