soil solution nitrate concentration in paddy-upland rotation system

A three-year field experiment (May 2023 – December 2025) at Songming Agricultural Environment and Soil Field Observation Station, Yunnan, China (25°21′N, 103°06′E). Two rice-based rotation systems (rice-garlic, rice-soybean) under five fertilization treatments (CK, CF, OF1, OF2, OF3), three replicates each. Rice paddies managed under alternate wetting and drying (AWD) irrigation.

Files:

modeling_dataset.csv — Weekly soil solution NO₃⁻ (target), NH₄⁺, in-situ sensor readings (soil temperature, moisture, EC at 20 cm), laboratory-measured solution chemistry, and derived AWD classification. n = 2,769.

soil_properties.csv — Annual soil background properties per plot: pH, soil organic carbon (SOC, g/kg), total nitrogen (TN, g/kg), available nitrogen (AN, mg/kg), bulk density (BD, g/cm³). n = 180.

daily_meteorology.csv — Daily on-site weather station data: wind speed (m/s), air pressure (hPa), air temperature (°C), air moisture (%), vapor pressure (kPa), photosynthetically active radiation (µmol/m²/s), rainfall (mm). n = 966 days.

fertilization_events.csv — Fertilization records: date, stage (base/tillering/heading/topdressing), chemical N rate (kg/ha), organic N rate (kg/ha), by rotation × treatment × year × crop. n = 129 events.

cropping_calendar.csv — Sowing and harvest dates for each rotation × year × season × crop combination. n = 12 seasons.