The LTAR Croplands Common Experiment (CCE) is designed to provide the knowledge needed to sustainably intensify U.S. row crop production. The objectives of the Croplands Common Experiment are to:
- Develop and evaluate production systems that promote the sustainable intensification of cropland agriculture;
- Identify, quantify, and understand mechanisms underlying tradeoffs and synergies among ecosystem services; and
- Use common long-term measurements and observations to understand and model ecosystem service outcomes under future projections of climate variability and change.
The LTAR Common Experiment at all sites compares Business-as-Usual (BAU) to Aspirational (ASP) systems and practices that have the potential to achieve sustainable intensification goals.
The LTAR Common Experiment at KBS is called the Aspirational Cropping System Experiment (ACSE). The Aspirational treatment at KBS was developed and is continually refined using a collaborative approach that brings together stakeholders and scientists to define intended outcomes and specific practices. It is designed to increase productivity, including yields, yield stability and profitability; produce positive environmental outcomes related to soil health, climate change, and biodiversity; and promote rural prosperity, including farm and community well-being.
Treatments within the ACSE began in 2022 and include a conventionally managed corn-soybean rotation using prevailing practices (BAU) compared to a five-year crop rotation with livestock integration and conservation practices (ASP). Crops in the ASP rotation include corn, soybean, winter wheat, winter canola, and perennial forage. Other key ASP practices include:
- cover crops are used to fill gaps between cash crops and harvested for forage, when possible,
- no tillage,
- fertilizers are used at reduced rates and applied with precision in space and time,
- prairie strips are planted in the middle and edge of each field,
- composted manure is added once every five years, and
- decision making is adaptive based on conditions, data, pest pressure, and other real time factors.
The ACSE experimental design includes both plots (to provide the more controlled environments needed for some measurements) and fields (to replicate the spatial variability faced by farmers). Plots are 28 x 85 meters (0.24 ha) and include four replicates of each crop entry point within each system, plus four replicate plots of restored prairie. Fields range in size from 5 to 14 hectares and include two replicates of each crop entry point within each system. A minimum of two 9-meter-wide prairie strips are included in each ASP field. Some ASP fields have additional prairie plantings on particularly low yielding areas of the field, as identified based on yield maps from prior years. In total, 121 hectares of KBS cropland are used for the ACSE.
Treatment names start with BAU for Business-as-Usual and ASP for Aspirational. Numbers are added after each acronym to indicate the specific crop within each system.
- BAU1 – Business-as-Usual starting with corn in 2022
- BAU2 – Business-as-Usual starting with soybean in 2022
- ASP1 – Aspirational starting with corn in 2022
- ASP2 – Aspirational starting with soybean in 2022
- ASP3 – Aspirational starting with wheat in 2022
- ASP4 – Aspirational starting with canola in 2022
- ASP5 – Aspirational starting with perennial forage in 2022
- ASP6 – Aspirational restored prairie seeded in 2022
Composted manure is added to the ASP plots and fields prior to each corn crop, resulting in applications to ASP1 in 2022, ASP5 in 2023 and so on. The specific practices used in the ACSE are updated over time to reflect prevailing practices (BAU) and improvements to the ASP system based on system observations / data and feedback from ongoing stakeholder relations. Major changes to crops or principles for each system are considered on a five-year basis.
Subplots established within ACSE treatment plots address specific process level hypotheses:
- ASP1, ASP2, ASP3, ASP4, ASP5 include a subplot (5×10 meters) where composted manure is not applied. Nutrients are replaced with synthetic fertilizers.
Each ACSE plot also contains a semi-permanent set of 3 sampling stations at which most within-plot sampling is performed.
Maps:
- Current Main Site
- Current Fields
- Archived Main Site (2021 onward)
- Archived Fields (2021 onward)
Information
- Publications
- Data (search under LTAR Aspirational Cropping System Experiment)
Major changes in management of treatments
- 2023 — Spring canola replanted in reps 1 and 2, and parts of fields 1 and 2 due to slug damage to winter canola.
- 2022 — Treatments initiated out of intended sequence following corn residue from 2021. Spring wheat substituted for winter wheat, spring canola substituted for winter canola, Perennial forage planted in the spring instead of summer and included oats as a nurse crop.
- 2021 — All plots and fields planted to corn for grain using prevailing practices for baseline study.