In order to investigate and provide data on the role of N-rates on canopy space and development in soybeans, varying rates of N (10, 20, 30 and 40 lbs/ac) will be used. All fertilizer treatments will receive 23 lbs/ac of P and 30 lbs/ac of K. In addition to fertilizer treatments, an additional soybean (@ 10 lbs N/ac) + weed treatment will be included, as well as a weed only treatment for a total of 6 experimental treatments (10, 20, 30 and 40 lbs/ac, 10 lbs N/ac + weeds, and weeds). Each treatment will be analyzed in a randomized complete block design with a plot size of 8 rows (30” spacing), 60 feet long each, with a targeted planting population of 130,000 seeds/ac. Each treatment will be replicated a minimum of four times. Yield data and nodulation counts will be collected in autumn 2021 and analyzed with an ANOVA followed with a Tukey posthoc mean separation to determine significant differences between treatments. SMSU Agronomy owns all farm equipment needed to conduct this research.
Additional collected data will include weekly aerial photography performed by drone. SMSU owns a DJI-Mavic Pro drone with high resolution photography capabilities which is routinely used for courses and projects. Aerial imagery will be taken weekly at solar noon (to minimize the impact of shadows during image analysis) throughout the growing season until all treatments fill their canopy space. In order to analyze these images, a student worker will load them into the ImageJ program, isolate the plant parts that need measurement, and calculate the canopy space in feet2. Once the canopy space has been calculated, we can analyze each sampling date with ANOVA to determine any different in canopy development as a function of N-fertilization.
The best way to describe how ImageJ works is with a demonstration. As such, a representative image of how students use these drones to take aerial imagery and how they can manipulate the photos with the ImageJ software to address agronomic questions has been included in this proposal (Fig. 1). In the attached image, ImageJ was used to change the color of the corn plants within a research plot to be white, and the weeds to be red. The program that allows the color coding of plants will also “count” the number of red pixels in the photo, and with proper calibration, can estimate the area dominated by weeds, and those dominated by crops. In taking weekly aerial images, students funded by this grant will be able to experience a rudimentary form of precision scouting without having to purchase an expensive sensor, nor learn complicated programs needed to process NDVI data. ImageJ is relatively user friendly and I haven’t had any trouble teaching students how to use it in my “AGRO 390 Precision Ag” class.
Figure 1 ImageJ manipulated photo of weed presence (red) in a corn plot (bright white). ImageJ is also able to calculate the red area to estimate how much "canopy space" the weeds are taking up. Photomanipulation and analysis conducted by a Junior Agribusiness major in AGRO 390 Precision Ag.
Data gathered from these weekly aerial images will provide the SMSU agronomy program with access to a season long look at the canopy development of soybeans and weeds. Additionally we will be able to see how canopy development changes as a result of fertilization status, and if additionally what N fertilization rate will have an impact on yield. Once all of this data is analyzed, GOAL 1 will be fulfilled. Additionally as much of this analysis and field work will be performed by a SMSU student intern, GOAL 3 will also be addressed.
GOAL 2 and 3 will primarily be met through utilization of data generated by this project in the class room. The list in the “Project Deliverables” section of the proposal describes how data will be used in at least five of SMSU’s Agronomy courses and achieve GOAL 2 and 3.
Project Deliverables: (limit 14,000 char.)
While the focus of this grant is centered on student education, the preliminary results of this project will be shared with the local farming community during the annual SMSU agronomy field day. Last year this event was attended by ~100 local farmers and business representatives and SMSU agronomy was able to showcase the type of research it was conducting at the farm. This is a great opportunity to brag on the department and provide a venue to others on how up and coming drone tech can be used in a field setting. While the research won’t be done in summer of 2022, a poster of our findings will be presented in summer 2023.
I also believe a major strength of this student managed project is that it utilizes non-specialized equipment. One of the most cost effective NDVI sensors runs at ~$2000 and doesn’t include the drone upon which it gets attached, nor the software to analyze any collected data. Additionally much of the NDVI research is still being conducted and while researchers are starting to understand correlations between NDVI values and crop health/yield, implementation of this information on a farm scale has not yet been attained. Furthermore, drones are becoming increasingly popular and affordable, especially within the farming community. A quick search of drones and any number of agricultural terms on Youtube.com will result in a large number of high quality, farmer-filmed, which are using drones to capture their footage. This project will synergize the growing popularity of drones with hands-on student learning needs, and provide the images and data I need for future assignments in the agronomy courses I teach. Furthermore, since drones are already popular with my ag students, I will get easy buy in and participation from them.
As mentioned, SMSU agriculture students will be able to use the plot as an educational tool to learn various aspects of soybean growth and development. Data generated from the field plot will be used to provide at least 5 different learning opportunities:
AGRO 132 Crop Production + Lab: This class is the equivalent of an “Agriculture 101” class and is required by all ag majors at SMSU. As such it averages ~20 students each fall semester. For one lab, students will go to the field and make observations on how varying N-rates changed plant growth and canopy space. Once we return to school, students will be presented with yield data as a function of N-rate, and be asked to make a “Yield response to fertilization” graph using the real world data. In a series of questions associated with the assignment they will be able to determine what the most economic N-rate would be at varying fertilizer price points. An example of such a graph is presented below using fake data (Fig. 2).
Figure 2 Crop yield response to increase of N fertilizer rate
AGRO 212 Grain and Forage Crop Management: This class is required by Agronomy and Agriculture Solutions majors, and averages around 11 students every other fall. The material covered in this course is the most agronomist centric of the agronomy courses and focuses on the production of corn, soy, and alfalfa and topics such as optimal planting rates, best fertilization practices, and genetic traits that impact production. This course covers these crops to a greater detail than any of the other agronomy courses. The field plots of this trial will be used in conjunction with a corn fertility trial as well as part of a field trip to the research plots. Photos taken of the fertility plots and personal experiences will be used and communicated in future lectures as well.
AGRO 341 Principles of Pest Management + Lab: This class is required by Agronomy and Agriculture Solutions majors, and averages around 9 students every fall. This class goes to the SMSU field plots every week to create scouting journals, and collect pests for a curated collection as part of a semester long project. The soybean + weed treatment of this project will provide an interactive demonstration of how weeds actively impact yield and time series data from the weed only treatment will help demonstrate how quickly weeds can outcompete a soybean field if allowed to canopy.
AGRO 390 Precision Ag: This class is required by Agronomy, Agriculture Solutions, and Ag Ed majors. As such it averages ~20 students each fall semester. This course covers precision agriculture tools including variable rate technology, equipment auto-guidance, remote and on-the-go sensing, and gets into the mechanisms of how these tools are utilized. The major assignment in this class is when students get a chance to fly the SMSU drone, take photos, and develop a project/answer a question using the ImageJ program. Fig. 1 is an example of one such student project. This proposal will create a time series of soybean and weed canopy growth at different N rates and give students “hands-on-experience” in analyzing remotely sensed data to make conclusions. Furthermore, they would be free to use the soybean plots while they are still standing to develop their own semester project.
AGRO 454 Experimental Design in Agriculture + Lab: This class is an Agronomy major elective offered every other spring. As such I have only taught it once and it had 7 students. I’m actively proselytizing this course to the Biology and Environmental Science department and expect a greater and more diverse enrollment in the future offerings of this course. In this class, students use real world data to learn about experimental design in typical agronomic test plots including assessment of insecticide sprays, the need for replication and blocking, and eventually are able to run an ANOVA to interpret findings from the field. Each week student analyze a new dataset, and the time series this proposal will generate will provide ample opportunities to answer a variety of crop production questions, as well as demonstrate the many ways in which viable data can be collected (drones!).