Spreadsheet for lysimeter data analysis

Authors: Evett, Steven - Steve; Marek, Gary; Colaizzi, Paul; Copeland, Karen; Ruthardt, Brice

Submitted to: Ag Data Commons
Publication Type: Database / Dataset
Publication Acceptance Date: 9/5/2024
Publication Date: 9/5/2024
Citation: Evett, S.R., Marek, G.W., Colaizzi, P.D., Copeland, K.S., Ruthardt, B.B. 2024. Spreadsheet for lysimeter data analysis. Ag Data Commons. https://doi.org/10.15482/usda.adc/26898151.v1.
DOI: https://doi.org/10.15482/usda.adc/26898151.v1

Interpretive Summary: The scarcity of water resources in the U.S. Southern High Plains is of regional, national and even international concern due to the fact that the region acts as a breadbasket for the nation and world. The majority of agricultural production in this region depends on irrigation, largely dependent on pumping from the Ogallala or High Plains Aquifer, which are yielding less water every year. From 1988 through 2024, scientists at the USDA ARS Conservation & Production Research Laboratory at Bushland, Texas, collected data that can be used to calculate crop water use and crop water productivity under irrigated and dryland conditions in the region’s climate, including for subsurface drip irrigation that can save water. They analyzed the data using a custom spreadsheet that allowed calculation of accurate values for crop water use, irrigation, and rainfall. Crop water use can be used to guide irrigation scheduling and water planning locally and regionally. Public accessibility via the USDA National Agricultural Library will increase use by other researchers developing more capable water management tools and crop water use and yield computer models.

Technical Abstract: A spreadsheet was designed for weighing lysimeter data analysis and reduction to values of evapotranspiration, dew and frost accumulation, precipitation, irrigation, and drainage tank emptying. Algorithms in the spreadsheet automatically identify precipitation and dew and frost accumulations in the 5-minute data, and places flags appropriately (“P” or “DW”) in a column that is referenced by formulae that separately calculate values for these. Noise can, however, cause false identification of precipitation or frost and dew accumulations, so another column is made available in which the user can enter flags to either nullify (“NO”) false automatic identification, or conversely, identify precipitation or dew and frost accumulations (“P” or “DW”) not automatically identified. This column also serves for entry of flags identifying irrigation, drainage tank emptying, counterweight adjustments, etc. Algorithms in other columns act upon these flags to correct the original raw relative storage values so that the adjusted relative storage reflects only evapotranspiration, while simultaneously computing 5-min values for precipitation, irrigation, dew and frost accumulation, and drainage tank emptying.