Interactive Effects of Cover Crops, Soil Health Practices, and Insect Community Dynamics on Corn Production

View the project final report

Commodities

• Agronomic: corn

Practices

• Crop Production: cover crops
• Farm Business Management: budgets/cost and returns
• Natural Resources/Environment: biodiversity
• Pest Management: integrated pest management
• Soil Management: organic matter

Many agricultural landscapes aim to maximize the amount of harvestable acres, which has resulted in most cropland becoming large monocultures whose productivity is maintained through a reliance on tillage, external fertilizers, and pesticides. This model of farm production has resulted in a reduction of biodiversity within the agricultural ecosystem. Despite the current paradigm of corn production, some farmers have developed a regenerative model of profitable farm production that promotes soil health and biodiversity. Little work has focused on the relative costs and benefits of these novel regenerative farming operations, which necessitates studying systems-level, farmer-defined best management practices.

Here, we evaluate the relative effects of regenerative and conventional corn production systems on pest management services, soil conservation, and farmer profitability and productivity throughout the Northern Plains of the United States. Insect diversity, soil properties, yield, and profitability were assessed in plots that were characterized as CONVENTIONAL: plots with no cover crop established with conventional pest management practices such as genetically modified (GM) corn and other insecticidal usage, or REGENERATIVE: plots in which a cover crop was established prior to corn, with non-GM corn and no insecticidal treatments, with a legacy of soil cover using cover crops. The overarching goal of regenerative farming systems is to increase soil quality and biodiversity in farmland while producing nourishing farm products profitably. The principles which are consistent across regenerative farming systems include 1) abandoning tillage (or actively rebuilding soil communities following a tillage event), 2) eliminating the occurrence of bare soil, 3) fostering plant diversity on the farm, and 4) integrating livestock into cropping operations. Further characterization of a regenerative system is difficult due to the various combinations of farming practices that comprise a system which targets the regenerative goal. 

Data were collected within systems that were defined and created by the producers, to give realistic insight on this systems-level question. Soil qualities were assessed by taking soil cores for analyzing soil organic matter (SOM) and determining soil bulk density. Insect communities in each field were assessed by analyzing insect dynamics using specimens collecting via soil cores, quadrat suction sampling, and by counting all insects on whole corn plants. Yields and profitability were examined and used to determine productivity and relative net profit on each operation.

Regenerative farming systems provided greater ecosystem services and profitability for farmers than the current input-intensive model of corn production. Pests were 10-fold more abundant on the conventional farms than on insecticide-free regenerative farms. Regenerative fields had 29% lower grain production but 78% higher profits over traditional corn production systems. These results indicate that ecologically based farming systems could be used to produce food while simultaneously conserving natural resources.

Outreach and explanation of these results are ongoing, and the results were shared with participating producers, as well as disseminated through an academic article. Our outreach highlights the fact that attaining this regenerative level of ecosystem functioning and profitability likely requires a systems-level shift on the farm -- meaning the use of multiple practices. Simply applying individual regenerative practices within the current crop production model will not likely produce optimal results. 

The objective of the study was to evaluate the relative effects of regenerative and conventional corn production systems on invertebrate community dynamics, insect pests, soil conservation, and farmer profitability and productivity throughout the Northern Plains of the United States.

We compared two crop production models to one another, in-situ. We directly compared farms using the current model of crop production, to those which have developed a regenerative model of farm production that promotes soil health and biodiversity. We examined soil qualities by taking soil cores for analyzing soil organic matter (SOM) and determining soil bulk density. Insect communities in each field were assessed by analyzing insect dynamics using specimens collecting via soil cores, quadrat suction sampling, and by counting all insects on whole corn plants. Yields and profitability were examined and used to determine productivity and relative net profit on each operation.