Nebraska research team developing autonomous planting robot for cover crops

Currently, the research team is working on planting the full 300 acres of Rogers Memorial Farm near Lincoln, Nebraska, by using their Flex-Ro robots.

According to Santosh Pitla, Associate Professor Machine Automation and Agricultural Robotics, planting 300 acres autonomously is a very ambitious goal. “We are working hard to develop robotic platforms (both UGVs and UAVs) to achieve autonomous agriculture at Rogers Memorial Farm. This will be contingent on continuous grant funding though.”

Hands-free farming

Pitla explains that his research team will also be collaborating with companies who are offering autonomous solutions for planting, targeted spraying, and fertilizer applications. “We are hopeful that public-private partnerships will help us getting close to hands-free farming at Rogers Memorial Farm”, he says.

“The next step is to take Flex-Ro to commercialization as Nebraska farmers are looking for labour saving solutions. We believe Flex-Ro will be a valuable technology tool in a farmer’s toolbox. We are in the process of starting a University supported start-up company to take this innovation into farmer’s hands in the next couple of years.”

“Based on a survey with producers in Nebraska, there seems to be an interest in autonomous cover-crop planting. Therefore, our first product will be an autonomous cover crop planter which will solve the labour challenges and also will contribute to soil health improvements and providing a value addition to the agribusiness of producers.”

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More trust in robots

Pitla emphasises that Nebraska has only one season every year. “We harvest around November, and between November and April, we have the winter. During that period, there is no crop in the field. And if you keep the soil bare, with no crop, there could be soil erosion. To mitigate that, farmers plant cover crops.”

“But the problem is that during the harvest, farmers don’t have a lot of labour available. A lot of people are busy with harvesting. And there is only a short window to plant cover crops, before the winter comes. That is the reason farmers could use the Flex-Ro robot to plant cover crops autonomously. We would also be addressing the labour challenges. Farmers seem to be very willing to adopt an autonomous cover crop planter to protect their soil health.”

Too risky

Currently, farmers in Nebraska are not ready to adopt a robot for autonomous planting of cash crops, Pitla points out. “Such as corn for example. That’s too risky for them. Alle operations are dependant on how well you plant the crop. So, that’s the reason why farmers first need to have more trust in robots. Also, farmers often have already invested in really good planting technology, such as large planters. So that’s a difficult sell.”

Value-adding the business with autonomously planting cover crops is more acceptable for farmers, Pitla says. “That is not going to affect the day-to-day operations. To make the commercial product more affordable for growers, the University supported start-up is planning to offer the autonomous cover crop planting robot as a service. “We are targeting a price of 18 to 20 dollar per acre. A lot of farmers would be interested in that.”

High-tech farm hands

Pitla sees robots and autonomy as a critical tool to help maintain agricultural productivity, especially because farmers are faced with an increasing shortage of workers. ““In those lines, I look at this robotic equipment as high-tech farm hands”, he says.

In addition to planting seeds autonomously in untilled soil, Flex-Ro can perform other field operations with minimal changes to its hardware and software. The robot first entered fields in 2019 to measure crop traits. It has been designed to be modular and reconfigurable, with different modes of steering ability available on the fly.

“We see Flex-Ro as an important tool that can do precise operations in the field, while saving costs”, Pitla explains. “We think of other tasks, such as targeted spraying and precision fertilizer application.”

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Collect data

Flex-Ro can also collect data through onboard sensors, used to measure reflectance, plant height, temperature and humidity. The machine has 6 computers and a CAN bus system, and the research team is looking into different camera technologies.

The 3,800-pound (1,724 kg) machine sits on an adjustable high-clearance platform and is powered by a gas engine. Each wheel contains an electric and hydraulic motor that can be steered in four different modes.

An operator to monitor

After setting a GPS, the robot can navigate autonomously to plant, and it will stop if it meets an obstacle. It works under the mode of supervised autonomy. The robot still needs an operator to monitor it when planting and requires supervision when moving from one field to another.

For the planting project last year, the autonomous planter team included agricultural engineering graduate student Ian Tempelmeyer and agricultural systems technology undergraduates Landon Sokol, Seth Chandler and Zane Rikli.

Tempelmeyer picked up on the progress of previous graduate students and decided to take on the challenge of automated seeding. He spent about six months analysing the mechanics, finally deciding on a design that would provide enough force to penetrate no-till soil.

Easy to use

“We made a quick realization that a drawn implement in a traditional manner wasn’t going to work. You needed a certain downforce”, he says. “We came up with the idea to put it inside the wheelbase; that’s something I hadn’t seen.”

Making sure the equipment would run safely and smoothly required a lot of trial and error. Eventually, the students refined the code and calibrated the machine enough for more sophisticated controls, such as adjusting the speed and handling terrain changes.

The team believes the Flex-Ro could be a product which, in the future, could aid researchers with a few acres of plots, to farmers with thousands of acres. Pitla: “We want to give farmers a system that is easy to use, and not to complicated. And for climate-smart agricultural practices, it is very important to have modular technologies tools, and robotics, automation, AI. All of these need to be combined in a synergistic way. So that we can create functional systems that will help to apply less but produce more, without effecting the environment in a negative way.”