Ouma, Turry; Barthel, Matti; Oluoch, Kevin Churchill; Otinga, Abigael; Njoroge, Ruth; Leitner, Sonja; Oduor, Collins; Agredazywczuk, Phillip; Zhu, Yuhao; Tamburini, Federica; Obozinski, Guillaume; Six, Johan; Harris, Eliza: Bulk soil stable isotope compositions and elemental concentrations measured from soil cores in smallholder maize and potato plots in Uasin Gishu County, Kenya [dataset]. PANGAEA, https://doi.pangaea.de/10.1594/PANGAEA.995351 (dataset in review), In: Ouma, T et al.: A multi-variable high-resolution dataset of N2O fluxes, isotopologue signatures, greenhouse gas fluxes, soil mineral nitrogen, microclimate, and crop yield from smallholder maize and potato systems [dataset bundled publication]. PANGAEA, https://doi.pangaea.de/10.1594/PANGAEA.995337 (dataset in review)
Abstract:
Bulk soil stable isotope compositions (δ¹³C, ‰ vs. VPDB; δ¹⁵N, ‰ vs. air N₂) and elemental nitrogen and carbon concentrations (N%, C%, C:N ratio) measured at during different agronomic events from soil cores across the full randomised complete block design in Uasin Gishu County, Kenya. Soil cores were collected at three depths (0–20, 20–40, 40–60 cm) across all treatment plots receiving nitrogen rates of 0, 25, 50, 75, 100 and 125 kg N ha⁻¹. Dried and ground samples were analysed by elemental analyser coupled to isotope ratio mass spectrometry (EA-IRMS), calibrated using alanine (δ¹³C = −27.44‰, δ¹⁵N = +1.18‰), tyrosine (δ¹³C = −23.99‰, δ¹⁵N = +5.30‰), and caffeine (δ¹³C = −34.50‰, δ¹⁵N = −3.18‰) as international reference standards. Data were collected at the University of Eldoret, Uasin Gishu County, Kenya (0°34′45″N, 35°18′22″E; 2,213 m a.s.l.) on Ferralsol soils. Bulk soil δ¹³C and δ¹⁵N integrate the isotopic imprint of long-term soil organic matter dynamics and fertilisation history. This dataset is part of a multi-variable collection archived at PANGAEA.
Supplement to:
Ouma, Turry; Barthel, Matti; Oluoch, Kevin Churchill; Otinga, Abigael; Njoroge, Ruth; Leitner, Sonja; Oduor, Collins; Agredazywczuk, Phillip; Zhu, Yuhao; Tamburini, Federica; Obozinski, Guillaume; Six, Johan; Harris, Eliza (submitted): A multi-variable dataset of N₂O fluxes, isotopologue signatures, soil mineral nitrogen, greenhouse gas emissions, and microclimate from smallholder maize and potato systems in Uasin Gishu County, Kenya (March 2024–March 2025). Earth System Science Data
Related to:
Oluoch, Kevin Churchill; Njoroge, Ruth; Otinga, Abigael; Mutua, Scholastica; Ouma, Turry; Agredazywczuk, Phillip; Barthel, Matti; Six, Johan; Collins, Oduro; Leitner, Sonja; Tufail, Muhammad; Oyugi, Antony; Harris, Eliza (preprint): Fate of Nitrogen in Rainfed Maize (Zea mays) Systems of the Tropical Highlands of Kenya Under Increasing Nitrogen Fertiliser Application Rates. https://doi.org/10.2139/ssrn.5912075
References:
Butterbach-Bahl, Klaus; Gasche, R; Breuer, Lutz; Papen, H (1997): Fluxes of NO and N2O from temperate forest soils: impact of forest type, N deposition and of liming on the NO and N2O emissions. Nutrient Cycling in Agroecosystems, 48(1-2), 79-90, https://doi.org/10.1023/A:1009785521107
IUSS Working Group WRB (2007): World Reference Base for Soil Resources 2006, first update 2007. World Soil Resources Reports No. 103. FAO, Rome
Zhu, Yuhao; Butterbach-Bahl, Klaus; Merbold, Lutz; Oduor, Collins; Gakige, Jesse Kagai; Mwangi, Paul; Leitner, Sonja (2024): Greenhouse gas emissions from sheep excreta deposited onto tropical pastures in Kenya. Agriculture, Ecosystems & Environment, 359, 108724, https://doi.org/10.1016/j.agee.2023.108724
Funding:
Swiss National Science Foundation (SNF), grant/award no. 207348: N2O-SSA: Combining measurements, modelling and machine learning to improve N2O accounting for sustainable agricultural development in sub-Saharan Africa
Coverage:
Latitude: 0.579720 * Longitude: 35.306110
Date/Time Start: 2024-04-04T03:00:00 * Date/Time End: 2025-01-31T03:00:00
Minimum DEPTH, soil: 0.1 m * Maximum DEPTH, soil: 0.5 m
Event(s):
Parameter(s):
| # | Name | Short Name | Unit | Principal Investigator | Method/Device | Comment |
|---|---|---|---|---|---|---|
| 1 | Type of study | Study type | Ouma, Turry | |||
| 2 | DATE/TIME | Date/Time | Ouma, Turry | Geocode – UTC | ||
| 3 | Treatment: nitrogen fertilisation | T:N fert | kg/ha | Ouma, Turry | Urea (46% N) applied in 3 split applications | |
| 4 | Treatment: crop type | T:crop | Ouma, Turry | Maize (H 6213) or Potato (Bidii) | ||
| 5 | Species, unique identification | Species UID | Ouma, Turry | Crop type | ||
| 6 | Species, unique identification (Semantic URI) | Species UID (Semantic URI) | Ouma, Turry | Crop type | ||
| 7 | Species, unique identification (URI) | Species UID (URI) | Ouma, Turry | Crop type | ||
| 8 | Agronomic event | Agronomic event | Ouma, Turry | |||
| 9 | Depth comment | Depth comm | Ouma, Turry | Soil sampling depth interval | ||
| 10 | DEPTH, soil | Depth soil | m | Ouma, Turry | Geocode – mean | |
| 11 | Depth, soil, minimum | Depth soil min | m | Ouma, Turry | upper | |
| 12 | Depth, soil, maximum | Depth soil max | m | Ouma, Turry | lower | |
| 13 | Sample mass | Samp m | mg | Ouma, Turry | Analytical balance, Sartorius, MCI AC 210 S | Dried ground soil sample weight for EA-IRMS |
| 14 | δ13C | δ13C | ‰ PDB | Ouma, Turry | UV/VIS Spectrophotometer, BIOBASE, BK-D590; coupled with Isotope ratio mass spectrometer (IRMS), Elementar, IsoPrime100 | soil, bulk; vs VPDB; calibrated with alanine, tyrosine, caffeine |
| 15 | δ15N | δ15N | ‰ air | Ouma, Turry | UV/VIS Spectrophotometer, BIOBASE, BK-D590; coupled with Isotope ratio mass spectrometer (IRMS), Elementar, IsoPrime100 | soil, bulk; vs air N2; calibrated with alanine, tyrosine, caffeine |
| 16 | Nitrogen, total | TN | % | Ouma, Turry | UV/VIS Spectrophotometer, BIOBASE, BK-D590; coupled with Isotope ratio mass spectrometer (IRMS), Elementar, IsoPrime100 | soil; by dry combustion |
| 17 | Carbon, organic, total | TOC | % | Ouma, Turry | UV/VIS Spectrophotometer, BIOBASE, BK-D590; coupled with Isotope ratio mass spectrometer (IRMS), Elementar, IsoPrime100 | soil; by dry combustion |
| 18 | Carbon, organic, total/Nitrogen, total ratio | TOC/TN | Ouma, Turry | Calculated | Molar C/N ratio, soil. Calculated from TOC% and TN% | |
| 19 | Sample ID | Sample ID | Ouma, Turry | |||
| 20 | Block | Block | Ouma, Turry | Randomized complete block design (RCBD) | Replicate |
License:
Creative Commons Attribution 4.0 International (CC-BY-4.0) (License comes into effect after moratorium ends)
Status:
Curation Level: Enhanced curation (CurationLevelC)
Size:
1505 data points