MAIN CROPPING SYSTEM EXPERIMENT – MAIN SITE

KBS LTER Plot MapThe Main Cropping System Experiment (MCSE) is the signature long-term experiment at KBS LTER. It is comprised of 4 annual crop treatments, 3 perennial crop treatments, and 4 successional communities. Seven treatments (T1-T7) are located at the main site complex as diagrammed in the main site layout map at left. Each treatment (T1-T7) is assigned to a 1 ha plot in 1 of 6 replicate blocks.

The annual crops (T1-T4) are corn – soybean – winter wheat rotations. Treatments 1 and 2 receive conventional levels of chemical inputs, with Treatment 1 chisel plowed and Treatment 2 under no-till management. Treatments 3 and 4 are biologically based low chemical input systems with a winter leguminous cover crop; Treatment 3 receives banded herbicide and starter N at planting, and Treatment 4 (certified organic) receives no chemical inputs nor compost or manure. Both Treatment 3 and Treatment 4 receive additional post-planting cultivation and Treatment 4 is rotary-hoed to control weeds.

The perennial systems include continuous alfalfa (Treatment 6) and trees (Treatment 5), the latter planted to a fast growing Populus clone on a 10-year rotation cycle. Treatment 7 is a native successional treatment, abandoned after spring plowing in 1989 and annually burned from 1996. Treatment 8 is a never plowed site, 200 meters (m) south of the others, that serves as an historical control for soil organic matter studies, and since 1985 has been shared with the Interactions Experiment.

Also included in the MCSE are successional fields abandoned from agriculture in the 1950s (TSF), coniferous forest plantings (TCF), and mature deciduous forests never cleared for agriculture (TDF). These are located close to the MCSE Main Site and are described at MCSE Successional and Forest sites.

Each MCSE plot also contains a permanent set of 5 sampling stations at which most within-plot sampling is performed. See sampling station location maps below.

Summary and Additional Information

Citations     Data Tables     Site History     Site Soils

Experiment lifetime
  • 1989 – present
Treatments
  • Conventional Management – Corn/soybean/wheat (T1)
  • No-till Management – Corn/soybean/wheat (T2)
  • Reduced Input Management – Corn/soybean/wheat (T3)
  • Biologically Based Management – Corn/soybean/wheat (T4)
  • Poplar (T5)
  • Alfalfa (T6)
  • Early Successional (T7)
  • Mown Grassland – never tilled (T8)
  • Mid-successional (SF)
  • Coniferous Forest (CF)
  • Deciduous Forest (DF)
Long-term sub-plots
  • Treatments 1 and 2 contain +/- herbicide subplots (1989 – present).
  • Treatments 3 and 4 contain +/- herbicide and +/- nitrogen fertilizer subplots (2006 – present).
  • Treatment 5 contains nitrogen fertilizer subplots (2011 – present).
  • Treatment 7 contains tillage and +/- nitrogen fertilizer subplots (1989 – present).
Plot size and replication
  • Treatments 1-7: 105 x 87 meters (~1 hectare), 6 replicate blocks
  • Treatment 8: 15 x 40 meters, 4 replicates
Maps:
Major Management Changes
  • 1989: T5 Poplars planted as stem cuttings (Populus × canadensis Moench ‘Eugenei’ ([Populus deltoides × P. nigra], also known as Populus × euramericana ‘Eugenei’).
  • 1993: T1-T2 rotation changed from corn-soybean to corn-soybean-wheat to match T3 and T4 rotations.
  • 1994: T1 cultivation changed from moldboard plow to chisel plow.
  • 1994: T2 (Replicate 5) accidentally plowed. Renamed T21.
  • 1997: T7 Biannual spring burning implemented to prevent tree colonization.
  • 1999: T5 Poplars harvested in February and allowed to coppice (stem sprout).
  • 2002: T7 Annual spring burning implemented.
  • 2008: T5 Poplars harvested in January and allowed to go fallow for field season in order to suppress weeds.
  • 2009: T5 Poplars replanted as stem cuttings of Populus nigra x P. maximowiczii (‘NM6’).
  • 2009: T1-T3 Soybean varieties changed from conventional to transgenic (glyphosate resistant); T4 variety remains conventional.
  • 2009: T3 Soybean weed control changed from mechanical + banded herbicides to broadcast application of glyphosate (same as T1).
  • 2011: T1-T3 Corn varieties changed from conventional to transgenic (glyphosate, European corn borer, and root worm resistant); T4 variety remains conventional.
  • 2014: T1-T3 Switched to low pressure injection system for N application.
  • 2016: T1-T3 Switched to stream bar nozzle application system for N application in wheat.