The Potential of Fragipans in Sustaining Pearl Millet during Drought Periods in North-Central Namiba (dataset)

Abstract

Sandy soils with fragipans are usually considered poorly suited for agriculture. However, these soils are cultivated in north-central Namibia as they can secure a minimum harvest during droughts. To understand the hydrological influence of fragipans in these soils, Ehenge, and what makes them valuable, their soil moisture content was measured over a time span of four months. These data were then compared to a deep soil without fragipan, Omutunda, which is more productive during normal years, but less productive during droughts. The results illustrate that the combination of sandy topsoil and shallow fragipan has beneficial effects on plant available water during dry periods, because of three reasons: (i) The high infiltration rate in the sandy topsoil, (ii) the prevention of deep drainage of water by the fragipan, and (iii) the limited evaporation losses through the capillary rise in the sand. The results also confirm the disadvantages of Ehenge during wet periods.

Description of Dataset

The dataset comprises a .pdf-file with a detailed data description, seven .csv-files (relevant datasets), and two txt-files with the R-code to produce the relevant Figures 4 and 5 from the paper “The Potential of Fragipans in Sustaining Pearl Millet during Drought Periods in North-Central Namibia” by Prudat et al. 2021.

File description
Rainfall.csv: daily rainfall in mm at two locations (Omutunda & Ehenge)
NDOB13_ehenge.csv/ NDOB13_omutunda.csv: soil temperature and soil moisture per minute
NDOB13_ehenge_daily.csv/ NDOB13_omutunda_daily.csv: soil temperature and volumetric soil moisture content (θTDR) aggregated per day using the arithmetic mean
NDOB13_ehenge_RASW_daily.csv/ NDOB13_omutunda_RASW_daily.csv: The relative available soil water (RASW) was calculated based on the measured plant available water,

Scripts
(1) RASW_rainfall_daily: Script to calculate and plot the relative available soil water (RASW) at the two stations and the rainfall
(2) Max_soil_surface_temperature: Script to calculate and plot the maximum soil surface temperature at the two stations

References

Cobos, D., Campbell, C., 2007. Correcting temperature sensitivity of ECH2O soil moisture sensors. Decagon Devices Pullman WA.

Hillel, D., 1998. Environmental soil physics: Fundamentals, applications, and environmental considerations. Academic press.