Book Description

Over the past 40 years, many corn (Zea mays L.) and soybean (Glycine max L.) growers in Pennsylvania transitioned from conventional tillage to reduced tillage and no-till systems, which reduce soil erosion and promote soil health. However, there are multiple management tradeoffs in long-term no-till cropping systems. The need for effective residue management in no-till cropping systems resulted in the recent adoption of 'vertical tillage,' which is primarily a residue management practice characterized by cutting and incorporating crop residue within the top 5-10 cm of soil. Though vertical tillage is widespread, minimal scientific information is available to document crop production and soil conservation tradeoffs related to this practice. Replicated on-farm field trials were conducted over a two-year period in 2021-2022 in southeast Pennsylvania to study the effects of vertical tillage on crop performance, pest management and soil health metrics. Key results of the project, relative to no-till, indicate vertical tillage results in moderate reductions in surface residue cover, winter annual weed cover and the incidence of slug damage. Across strip trial locations, surface residue cover from a previous grain corn crop was reduced 16% on average when employing vertical tillage once annually in the spring. In addition, vertical tillage resulted in surface residue cover reductions below a state conservation program compliance threshold (>= 60% residue cover) approximately 18% of the time as influenced by equipment type and intensity of use. While vertical tillage may locally influence these factors, depending on field characteristics and weather conditions, the treatment effect is likely not large enough to alter chemical weed management or avoid early season pest problems associated with additional crop residue. Regarding soil health, results suggest vertical tillage may not alleviate soil test phosphorus or organic matter stratification in long-term no-till cropping systems but may reduce surface compaction while potentially creating a compacted layer below the working depth of these tools. The primary objective of this thesis research was to provide sound scientific data from on-farm trials to improve grower and policy maker decision-making related to whether vertical tillage has a role in conservation agriculture on southeast Pennsylvania farms, which are located within the environmentally sensitive Chesapeake Bay Watershed.