KBS152:Switchgrass Nitrogen Fixation Experiment
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.
- Status: active
- Temporal Coverage 2018-10-15 to 2022-12-02
Tables
- KBS127-006 Switchgrass Yields
Dry matter switchgrass yields from machine harvests of the Switchgrass Nitrogen Fixation Experiment (plots 1-16). Plots were converted from the corn-soybean-wheat rotation of the LTER Main Cropping System Experiment (MCSE) to switchgrass in 2016, with the first harvest in 2018. See the Interactions Experiment for agronomic grain yields before conversion.
This experiment was retired in 2022 and herbicided in 2023. There is no harvest from these plots in 2023- KBS128-001 Agronomic Soil Chemistry
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.
- KBS128-003 Soil Moisture under Rainout Shelters
Soil moisture measured at two depths (10 and 25 cm) in surface soils under the rainfall exclusion shelters of the Switchgrass Nitrogen Fixation Experiment. Soils under shelters manually received rainfall on differing schedules.
- KBS128-004 Switchgrass Stand Counts
Stand counts of switchgrass populations of the Switchgrass Nitrogen Fixation Experiment periodically conducted in the spring to assess growth and recruitment.