Dataset for fertilizer-derived nitrogen partitioning in rice–soil systems under water-saving and flooded irrigation using a ¹⁵N tracer

This repository provides the processed, figure-ready dataset used to generate the tables and figures in the associated manuscript on artificial humic substances (AHS) and irrigation effects on fertilizer nitrogen (N) fate in a paddy rice system. The underlying research hypothesis is that AHS can reallocate fertilizer-derived N toward crop recovery and away from the apparent loss fraction, and that the magnitude of this effect is modulated by irrigation regime (water-saving irrigation vs flooded irrigation). Data were generated from a replicated field experiment using a field-embedded ¹⁵N tracer microplot approach. Treatments combined two irrigation regimes with graded AHS application levels. Plant and soil samples were collected at maturity, and total N and ¹⁵N enrichment were used to quantify fertilizer-derived N recovered in plant pools, retained in soil, and assigned to an apparent loss pool by isotope-based mass balance. The Excel file contains the curated values used for plotting, including (where applicable) treatment identifiers, replication/grouping variables, means and/or replicate-level values, and derived indices such as fertilizer-derived N in plant/soil pools, partitioning proportions, and apparent nitrogen recovery efficiency (NRE). Variable names and units are provided in the spreadsheet to support interpretation. Notable patterns reflected in these plotting data include increased fertilizer-derived N recovery by rice with AHS across irrigation regimes, a shift in fertilizer-N partitioning toward plant (grain/straw) pools, and a reduced relative contribution of fertilizer-N to the apparent loss fraction. The dataset enables readers to reproduce the visualizations and summary comparisons reported in the manuscript and can be reused for cross-study comparisons, meta-analyses, or model evaluation where processed ^15N-based fertilizer-N partitioning metrics are required. This upload contains processed data used for figure construction rather than raw instrument outputs. Users should interpret values in the context of the experimental design (AHS level × irrigation regime) and consult the spreadsheet headers/notes for units, abbreviations, and calculation conventions.