Search

In spring 2016, a course at Ohio State University (OSU) was introduced to teach advanced agronomic concepts and included the option to prepare students for the Certified Crop Adviser (CCA) exams offered by the American Society of Agronomy. From 2019 to 2021, revisions in instructional methods were implemented that introduced the use of pretests (in addition to posttests given at the end of instructional periods) and focused problem-solving within a teaching unit towards the end of the semester. Improvement in course exam performance for each period was measured, and student performance (SP) on the CCA exams relative to the general population was determined. Student course exam scores increased marginally (3%) from 2019-2021 compared to 2016-2018, though gains were not significant (p > 0.5). SP from 2016 to 2018 (n = 27) was 1%-5% greater than the general population for the international CCA exam (n = 3978) but was equal to or 1.5% below the general population for the local CCA exam (n = 784). SP from 2019 to 2021 (n = 21) was 7.8%-16.4% greater for all categories for both the international (n = 2330) and local (n = 419) exam general populations. Student passing rates on the international exam went from 25.3% to 52.8% greater than the general population from 2016-2018 to 2019-2021, respectively, and student passing rate for the local exam increased from 55.7% less than the general population in 2016-2018 to 26.7% greater than the general population in 2019-2021. These results suggest the modification of course instruction coincided with SP gains and may have contributed to improved performance of the student population compared to the general population.

The use of modern technological advances to aid with agricultural production has led to many new career opportunities in the agricultural industry especially for those with strong science, technology, engineering, and math (STEM) training. However, limited exposure to agricultural content in middle and high school education may affect how many students enter the industry. Professional development sessions and post-session surveys for teachers were designed to raise teacher awareness of careers in agriculture and current agricultural facts, quantify use of professional development materials in the classroom, and measure change in behavior of teachers and student perceptions in response to participation. Four professional development sessions were offered from 2017 to 2019 for teachers of grades 6-12. Sessions consisted of presentations, hands-on activities, and reflection and discussion on topics related to technology in agriculture. Although direct knowledge of agricultural facts did not increase (P = 0.2), teacher comfort in teaching about technology in agriculture and career opportunities did increase both in the short term and long term (P < 0.02). Curriculum related to nitrogen cycling and soil properties were most widely used, and 90% of survey respondents reported positive changes in student perceptions of careers in agriculture. These results suggest the professional development sessions were effective at enabling teachers to teach on these subjects, and student perceptions were positively impacted from teachers participating in the sessions.

Although there has been a resurgence in interest among farmers in producing narrow row hybrid maize (Zea mays L.) in the Eastern UnitedStates, agronomic recommendations for modern hybrids are limited. To address this issue, field trials were carried out from 2016 to 2018 in Ohio and Pennsylvania (10 unique site‐year combinations), aiming to answer the following questions: (i) Do modern hybrids differ in their response to narrow (38 cm) and conventional (76 cm) row spacing? (ii) Is there a yield increase for narrow row production? The study was planted in a split‐plot randomized complete block design with four replications. The whole plot factor was row spacing, and the subplot factor was hybrid. Two hybrids (P0506AM and P0604AM) were in an "early"‐season group, and two hybrids (P1197AM and P1443AM) were "full"‐season hybrids. Both P0506AM and P1443AM were identified as AQUAmax hybrids and had superior seed company drought tolerance ratings over their maturity pairing counterpart. Grain and forage yield were 4% and 8% greater, respectively, for the narrow row spacing across hybrids. Hybrid differences in drought tolerance designation did not result in grain or forage yield differences under varied row spacings. There was no hybrid × row spacing interaction. In most site‐years, P1197AM hybrid produced the greatest grain and forage yields, though P1443AM and P0506AM were similar in most cases. Results suggest a minor advantage in yield (≤8%) from narrow rows in Ohio and Pennsylvania, though other considerations that include cost to conversion should be considered prior to adoption. Core Ideas: Narrow row spacing increased maize grain and forage yield by 4% and 8%, respectively, over conventional spacing.Response to row spacing was similar across hybrids, that is, there was not a hybrid × row spacing interaction.Hybrid drought tolerance designation did not affect row spacing response.Full‐season maize hybrids produced greater grain and forage yield than early‐season hybrids, regardless of row spacings. [ABSTRACT FROM AUTHOR]

Seed is one of the most crucial inputs for soybean [Glycine max (L.) Merr.] production due to its influence on plant population, uniformity, and yield, as well as its cost as an input. Seeds of good quality have high germinability and vigor, providing an adequate stand with uniformly good growth and development even under adverse conditions. This study aimed to measure the effect of soybean planting date and seeding rate on harvested seed mass, seed germinability, and seed vigor. Seeds were collected from a field experiment during the 2020 and 2021 growing seasons at two locations in Ohio: Western Agricultural Research Station and Northwest Agricultural Research Station. The study was conducted using a split‐plot randomized complete block design (planting date–whole plot; seeding rate–subplot) with four replications. Standard germination and accelerated aging tests were conducted in the laboratory using seeds harvested from the field study. All four site‐years demonstrated that planting soybean very late (June 16–July 1) produced lower weight seeds than the other planting dates. Across planting date and seeding rate treatments, the harvested seed germinability was ≥94%. However, soybean planted in early June (June 1–June 15) had the lowest seed vigor results (64%–81%) compared to other planting dates (80%–89%). Rainfall at R7–R8 development stages is negatively correlated with the seed vigor. The results will help seed producers optimize seed production and quality and suggest avoiding planting in June to increase harvested seed vigor. Core Ideas: Later soybean planting dates were associated with reduced seed weight.Seeding rate did not impact seed germinability and seed vigor of harvested seed.Germinability of harvested seeds was ≥94% in all site‐years, regardless of the planting date or seeding rate.Soybean planted in early June produced seeds with the lowest seed vigor.Rainfall at R7–R8 development stages is negatively correlated with seed vigor. [ABSTRACT FROM AUTHOR]

The application of variable rate seeding (VRS) enables soybean [Glycine max (L.) Merr.] growers to allocate seed more efficiently on heterogeneous farmland and thus potentially increases profit by reducing seed cost and/or increasing yield. Successful implementation of VRS depends on the appropriate division of management zones where producers apply different seeding rates. We construct an economic conceptual model for evaluating the information conveyed by management zones. The model implies that distinct management zones should differ by marginal seed productivity when evaluated at the same seeding rate. Based on this model and a dataset collected from 10 on‐farm trials in Ohio and Michigan in 2017 and 2018, we implement a quadratic model regression analysis describing yield response to seeding rate. Results show that management zones in four out of 10 trials do not display statistically significant differences in marginal seed productivity. The small differences across management zones could result from the soybean plant's ability to compensate for yield due to fewer plants by increasing branches per plant and/or from inappropriately identified management zones. The estimated profit gains from applying VRS across the 10 trials vary from $0.20 to $30.60 ha−1. We also find that increasing seeding rate and mean yield decreases yield variability and yield skewness. Overall, the difference in marginal seed productivity is crucial for the appropriate determination of VRS management zones. Core Ideas: Successful implementation of VRS to increase profit requires management zones to differ by marginal seed productivity.For four out of 10 fields, VRS was unnecessary due to insignificant differences in marginal seed productivities.Increasing seeding rate and mean yield reduce yield variability and skew yield distribution leftward. [ABSTRACT FROM AUTHOR]

Selecting optimal corn and soybean seeding rates are difficult decisions to make. A survey of Ohio and Michigan farm operators finds that, although generally keen to learn from others, they tend to emphasize their own experience over outside information sources. Soybean growers declare university and extension recommendations as more important than do corn growers. In response to direct queries and in free comments, growers place more emphasis on understanding the agronomic and technological problems at hand than on adjusting to the market environment. Given the decision environment, we argue that these responses are reasonable. [ABSTRACT FROM AUTHOR]

Non-transgenic drought-tolerant (Tol) corn (Zea mays L.) hybrids may be a tool to help growers manage for precipitation variability during the growing season. However, there is little agronomic research on these hybrids in the eastern U.S. Corn Belt. A field study was conducted from 2012 to 2014 at three Ohio locations (Hoytville, South Charleston, and Wooster) to investigate the yield response of two Tol hybrids compared to two conventional (Con) hybrids of similar relative maturity at five populations (59,000; 74,000; 89,000; 104,000; and 124,000 plants ha-1) planted in May and June. The agronomic optimum plant population (AOPP) to produce maximum yield (AOMY) and the economic optimum plant population (EOPP) to maximize yield (EOMY) were determined using a quadraticplus- plateau model for Tol and Con hybrids as well as maturity group (short-season and full-season). Across all locations and hybrids, delayed planting resulted in an increase in AOPP compared to the May planting by 1300 plants ha-1, but EOPP decreased by 3100 plants ha-1. The drought-tolerant hybrids produced greater AOMY at lower AOPP compared to the conventional hybrids when planted in May, but typically exhibited lower AOMY at lower AOPP when planting was delayed until June. In environments with Con hybrid yield less than 12.2 Mg ha-1, a yield advantage was observed from planting a Tol hybrid. However, above this yield level Con hybrids produced greater yield than Tol hybrids. Short-season hybrids had a greater AOPP and lower AOMY as compared to full-season hybrids regardless of plant date. [ABSTRACT FROM AUTHOR]