Update:
This final project report covers the status of the project through October 5, 2023. The focus of this report is on planting-related activities and results since participating on-farm trial fields are just now being harvested and yield monitor data has not yet been collected from growers. Salin 247 will prepare another report and will be prepared to present results of the seed population part of the project later in the fall.
A key objective of this project was to demonstrate and evaluate the use of small, light-weight, autonomous farm machinery in conducting on-farm soybean trials. The attached final report focuses on this objective.
View uploaded report 
A key objective of this project was to demonstrate and evaluate the use of small, light-weight, autonomous farm machinery in conducting on-farm soybean trials. We have concluded that the small, light-weight, autonomous Salin 247 platform is well suited for doing on-farm trial work although there are improvements that should be addressed relative our 2023 project work. We summarize some of the results and learnings below.
1) Using the Salin 247 small, light-weight, autonomous planter worked generally very good for the soybean seed population on-farm trial project. Planting performance was very good. Data collected from the Precision Planting 20/20 monitor showed excellent population, singulation, duplicates, and skip data. Planting depth was mostly good as indicated by down force measurements.
2) Salin 247 did experience a number of GPS-related issues during the trial. These issues impacted our planting productivity – i.e., caused us significant downtime. Fortunately, we believe we have now corrected these GPS problems. We tested four different GPS receiver brands and believe now we have one that is performed as needed.
3) We have also been evaluating receiving online RTK GPS corrections. Last year we used a local base station for RTK corrections. After experiencing a few early problems, the online corrections now seem to be performing well although we have the option of using a local base station if Internet access in the field is not available through a cellular modem.
4) In addition to the navigation issues, we decided to implement a new navigation algorithm during the trial in order to reduce navigation errors. This was successful, and navigation errors are now acceptable, even at higher speeds. On the final field we planted, mean absolute error was about 1 inch with a standard deviation of 0.45 inches.
5) With the corrected GPS problems as well as a new navigation algorithm, we are confident in planting at 5 to 6 mph without any navigation issues.
6) Using the light-weight, autonomous planter without a traditional tractor, increased soil compaction very little. On average, soil compaction increased only 14 PSI in the top 4 inches of soil where the Salin 247 planter drove.
7) Planting productivity was lower than what we wanted due primarily to the GPS problems, but we have also concluded that we can run a larger planter that is more productive and does not increase soil compaction. Based on our experience in the field this year, our plan is to move to a 20-foot or possibly even a 30-foot toolbar from the 10-foot toolbar used this year. Based on data collected this size of autonomous planter will not increase soil compaction significantly compared to the current planter.
8) Salin 247 made the mistake of not going to all of the trial fields prior to creating the field trial plot layout and planting prescription. In two cases, we had to redo the planting prescriptions due to unforeseen issues that could have been avoided with an early visit to the field.
9) Salin 247 learned that it would be beneficial to plant a check buffer around the plot area of the field. Since Salin 247 typically planted only a portion of the trial fields, when the grower planted the remaining parts of the field there was some overlap of the grower planter into the plot area. If Salin 247 had planted a 20-foot or wider buffer, an overlap would not have been a problem.
10) Salin 247 should have scheduled a project review meeting early in the season (possibly early March) to review details of the project and address any grower questions. It seems that some of the participating growers this year didn’t have all the project information they needed. This could have been avoided with a project kickoff meeting.
11) This on-farm trail was very valuable to Salin 247 in terms of helping with future design and capability changes. It was also helpful in terms of learning more about implementing a successful on-farm trial.
12) We anticipate that once yield monitor data has been collected and analyzed, we will be able to share useful seed population study results with the participating growers as well as all Iowa growers. Salin 247 looks forward to assisting with the analysis and communicating the results later in the fall.