C-FARM Project: On-Farm Conservation Agriculture Practices Effects on Soil Health and Agronomic Productivity in the Midwestern USA

Yadunath Bajgai, C-FARM Research Scientist stands in front of winter wheat grown under no-till farming systems after soybean harvest at a farm in Wyandot county, Ohio in December 2023. Besides grain production, the winter wheat strategically acts as cover crop to protect soil over the winter.

By Yadunath Bajgai

A review of literature on the topic entitled ‘On-Farm Conservation Agriculture Practices Effects on Soil Health and Agronomic Productivity in the Midwestern USA’ has been completed and a summary is as follows. The manuscript has been submitted for publication and it is under review.

To sustain and increase food, feed, fiber and fuel production, care should be taken to protect soils against degradation. Key principles of CA such as minimizing soil disturbance, maximizing soil cover, and diversifying crop species can protect soils against degradation and enhance ecological resilience and soil health. Hence, a study was conducted using the Web of Science database to review the literature on CA practices and their effects on soil health and agronomic productivity in the Midwestern region of USA. Since, on-farm studies are suggested to be more representative than small plots for assessment of effect of farming systems on soils, research conducted on a working farm or ranch on a commercial-scale were selected for the review. Thus, small experimental plots within a farmer's field were excluded.

The highest number of papers covered Ohio, followed by Michigan, and the lowest number covered Kansas and South Dakota. The data collated indicated that a widely practiced cropping system in the Midwestern region of the U.S. is corn-soybean rotation in some form of spatial or temporal rotations, sometimes also including wheat with pastures/hay grasses., sometimes also including wheat with pastures/hay grasses. Soil properties such as bulk density, soil organic carbon content and its fractions, and total N were more commonly studied whilst properties like water infiltration rates, texture, available water capacity, water stable aggregates, pH, EC, soil chemical properties were either sparingly assessed or not assessed in soil under no-till (NT) vs. conventionally tilled (CT) comparison in on-farm conditions. Unlike in NT vs. CT soils, soil texture features as a more commonly assessed property in cover crops vs. without cover crop studies. Knowledge and research gaps were identified to be addressed in order to strengthen the existing database and to enhance the credibility of technical recommendations on CA practices to improve soil health and ecological resilience in commercial farms or ranches.

Additionally, thework in the laboratory to process and analyze soil samples for determination of soil properties has continued apace. Penetration resistance of the C-FARM sites in Pickaway and Wyandot counties has been completed and soil samples collected from these two counties are being processed for determination of aggregate stability.