Agronomic Soil Chemistry — Switchgrass NItrogen Fixation Experiement

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Agronomic chemistry of surface (0-25 cm) soils of the Switchgrass Nitrogen Fixation Experiment (plots 1-16) planted to switchgrass in 2016. Soils are occasionally collected in the fall (usually after harvest) for fertilizer and liming recommendations and analyzed for pH, lime index, phosphorus, potassium, calcium, magnesium, and cation exchange capacity by an analytical service laboratory.

This datatable is part of the Switchgrass Nitrogen Fixation Experiment dataset.

This dataset contains data from the Switchgrass Nitrogen Fixation Experiment established in 2016 after conversion of the historically tilled plots (1-16) of the Interactions Experiment from annual crops to switchgrass (Cave-in-rock). The experiment maintained the fertilizer treatment (fertilized and not fertilized) of the Interactions Experiment, but the tillage treatment was discontinued because switchgrass is a perennial crop that is not tilled. From 2018-2022, a rainout shelter experiment that also used buried mesocosms was conducted in the legacy no-till, no fertilizer plots (3, 6, 8, and 9) to examine the effect of soil wetting/drying regimes on the relationship between associative nitrogen fixation (ANF) and switchgrass phenology, diazotroph communities, and nifH expression. The experiment was retired after the 2022 growing season in order to establish the Switchgrass Biodiversity Experiment.


Experiment: Switchgrass NItrogen Fixation Experiement
Data available from: October 2018
Dataset: KBS152
Datatable ID: KBS128-001.9
Core Areas Inorganic Nutrients
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Last Updated 2024-04-30
Variate Description Units
sample date sample date
legacy tillage treatment CT = Conventional tillage, NT = No-till, F = fertilized, N = unfertilized
fertilization F: fertilized; N: not-fertilized
replicate replicate block
plot whole plots (1-16), and plot id+MO (2, 6, 9, 13) stands for plots that have monoliths installed within.
depth depth of soil sampled
pH pH
cec cation exchange capacity (meq/100g) meq/100g
phosphorus Bray P1 phosphorus (ppm) µg/kg
potassium Potassium (ppm) µg/kg
calcium Calcium (ppm) µg/kg
magnesium Magnesium (ppm) µg/kg
lime index Lime Index
year Sample year

Data Excerpt

sample_date legacy_tillage_treatment fertilization replicate plot depth ph cec phosphorus potassium calcium magnesium lime_index comment year
2018-10-15 NT F 2.0 0-25 cm 6.2 6.8891025 30.0 90.0 1015.0 190.0 70.0 2018.0
2018-10-15 CT N 3.0 0-25 cm 6.7 7.041282 37.0 85.0 1038.0 196.0 71.0 2018.0
2018-10-15 CT F 1.0 0-25 cm 6.0 5.844359 31.0 68.0 879.0 153.0 70.0 2018.0
2018-10-15 CT N 2.0 0-25 cm 6.5 6.749615 58.0 98.0 983.0 190.0 71.0 2018.0
2018-10-15 NT F 4.0 0-25 cm 6.2 5.931923 37.0 56.0 901.0 154.0 70.0 2018.0
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