Historical land management alters new soil carbon inputs by annual and perennial bioenergy crops
Data files
Jun 20, 2025 version files 27.74 KB
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MBC_SEOC_data.csv
2.24 KB
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Plant_clippings.csv
3 KB
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Plant_component_data.csv
5.45 KB
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Plant_New_C.csv
2.80 KB
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POM_MAOM_new_C.csv
2.46 KB
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README.md
4.55 KB
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Soil_C_pools.csv
7.25 KB
Abstract
Bioenergy and bioproduct markets are expanding to meet demand for climate friendly goods and services. Perennial biomass crops are particularly well suited for this goal because of their high yields, low input requirements, and potential to increase soil carbon (C). However, it is unclear how much C is allocated into belowground pools by perennial bioenergy crops and whether the belowground benefits vary with nitrogen (N) fertilizer inputs. Using in situ 13C pulse-chase labeling, we tested whether the sterile perennial grass Miscanthus × giganteus (miscanthus) or annual maize transfers more photosynthetic C to belowground pools. The experiment took place at two sites in Central and Northwest (NW) Iowa with different management histories and two nitrogen (N) fertilizer rates (0 and 224 kg N ha-1 yr-1) to determine if the fate of plant-derived soil C depends on soil fertility and crop type (perennial or annual). Maize allocated a greater percentage of total new 13C to roots than miscanthus, but miscanthus had greater new 13C in total and belowground plant biomass. We found strong interactions between site and most soil measurements – including new 13C in mineral and particulate soil organic matter (SOM) pools –which appear to be driven by differences in historical fertilizer management. The NW Iowa site, with a history of manure inputs, had greater plant-available nutrients (phosphorus, potassium, and ammonium) in soils, and resulted in less 13C from miscanthus in SOM pools compared to maize (approximately 64% less in POM and 70% less in MAOM). In more nutrient-limited soils (Central site), miscanthus transferred 4.5 times more 13C than maize to the more stable mineral-associated SOM pool. Our results suggest that past management, including historical manure inputs that affect a site’s soil fertility, can influence the net C benefits of bioenergy crops.
Description of each file and the variables within each file (along with units)
Files:
“Soil C pools”
contains C data for the four sampled soil zones: bulk, root bulk, near root, and rhizosphere
Variables
- Site = Name of farm. Allee is NW and Sorenson is Central
- Block: experimental block, ranging from 1-4 within a site
- Plot: experimental plot, one unique number across the experimental blocks within a site
- NRate: Nitrogen fertilization rate (0 or 224 kg ha-1 N)
- Crop: corn (maize) or miscanthus
- SoilZone: four categories of soil pools separated at destructive harvest: bulk, root bulk, near root, and rhizosphere
- Soil C: % soil C
- Delta13C: the delta 13C signal of the sample
- New C: the total new carbon (mg C/kg soil) derived from the labeled crop
“POM_MAOM new C”
contains C data for the rhizosphere soil POM and MAOM pools
Variables
- Site = Name of farm. Allee is NW and Sorenson is Central
- Block: experimental block, ranging from 1-4 within a site
- Plot: experimental plot, one unique number across the experimental blocks within a site
- NRate: Nitrogen fertilization rate (0 or 224 kg ha-1 N)
- DeltaPOMC: the delta 13C signal of the POM sample
- DeltaMAOMC: the delta 13C signal of the MAOM sample
- NewCPOM: the total new particulate organic matter (POM) carbon (mg C/kg soil) derived from the labeled crop
- NewCMAOM: the total new mineral associated organic matter (MAOM) carbon (mg C/kg soil) derived from the labeled crop
“MBC_SEOC_data”
contains microbial biomass C (µg C/gdw soil) and salt-extractable organic C (µg C/gdw soil) plus the delta 13C values for each pool.
Variables
- Site = Name of farm. Allee is NW and Sorenson is Central
- Block: experimental block, ranging from 1-4 within a site
- Plot: experimental plot, one unique number across the experimental blocks within a site
- NRate: Nitrogen fertilization rate (0 or 224 kg ha-1 N)
- Crop: corn (maize) or miscanthus
- MBC: microbial biomass carbon (µg C/gdw soil) derived from chloroform fumigation extractions
- SEOC: salt-extractable organic carbon (µg C/gdw soil)
- Delta13C: the delta 13C signal of the sample (MBC or SEOC)
“Plant clippings”
contains the %C content and 13C signature of the corn (maize) and miscanthus leaf punches 24 hours after the labeling event.
Variables
- Site = Name of farm. Allee is NW and Sorenson is Central
- Block: experimental block, ranging from 1-4 within a site
- Plot: experimental plot, one unique number across the experimental blocks within a site
- NRate: Nitrogen fertilization rate (0 or 224 kg ha-1 N)
- Crop: corn (maize) or miscanthus
- PercC: %C of sample
- Delta13C: the delta 13C signal of the sample
- AtomPerc: the atom % of the sample
“plant component data”
contains the %C content and 13C signature of both crops at harvest.
Variables
- Site = Name of farm. Allee is NW and Sorenson is Central
- Block: experimental block, ranging from 1-4 within a site
- Plot: experimental plot, one unique number across the experimental blocks within a site
- NRate: Nitrogen fertilization rate (0 or 224 kg ha-1 N)
- Crop: corn (maize) or miscanthus
- Part: plant component: leaves, roots, stems, or kernels/flowers
- PercC: %C of sample
- Delta13C: the delta 13C signal of the sample
“Plant New C”
contains the new C (derived from 13C enrichment) data for plant biomass at harvest
Variables
- Site = Name of farm. Allee is NW and Sorenson is Central
- Block: experimental block, ranging from 1-4 within a site
- Plot: experimental plot, one unique number across the experimental blocks within a site
- Crop: corn (maize) or miscanthus
- New 13C in total plant biomass at harvest: the new plant biomass (above and belowground biomass) carbon derived from the 13C-labeled CO2 (g 13C ha-1)
- Total new 13C in aboveground plant biomass at harvest: the new aboveground plant biomass carbon derived from the 13C-labeled CO2 scaled to one hectare (g 13C ha-1)
- Total new 13C in belowground plant biomass at harvest: the new belowground plant biomass carbon derived from the 13C-labeled CO2 scaled to one hectare (g 13C ha-1)
- Plant aboveground biomass: total aboveground plant biomass scaled to one hectare (Kg/ha)
- Plant belowground biomass: total belowground plant biomass scaled to one hectare (Kg/ha)
- Fraction of total new 13C belowground: the fraction of new plant biomass derived from the 13-C labeled CO2 that is belowground (% of total)