This summer, I started wondering what you might do to build a small farming robot to manage a home garden. I then discovered the interesting Farmbot project, which has been working on this for much longer, and has done much of what I thought might be useful. So I offer kudos to them, but thought it might be worth discussing some of the reasons why this is interesting, and a few new ideas.

The rough idea is to use robotics to manage a modest garden. It could be outside or in a greenhouse, or perhaps eventually a vertical farm on a wall. The simplest way to do this is to have a track and a gantry to allow the robot head to move to any spot in the rectangle and then do gardening tasks -- tilling, planting seeds, watering, weed killing, weeding, analysis and even perhaps harvesting.

Why do people have gardens? Some do it because they enjoy the task, or at least some portions of the task. Those folks may not be interested in a farming robot, though they might like one which does the tiresome tasks like weeding.

Others garden to save money on produce, particularly specialty produce which is organic and where they know all about how it was grown. Initially, the robot might be too expensive to allow you to save money unless you pretend to ignore the cost of the robot.

Perhaps most interesting is the ability to get a supply of superior produce that's already delivered to your house. The produce can be quite superior to agribusiness produce found in grocery stores, because many of those plants have been bred for things like shelf life, how well they pack and transport, how good they look on the shelf, yield, ripeness out of season and many other factors. The problem is, every time you breed for one of these, you breed out other things, including the most important -- flavour. People with no love of gardening as a hobby will still pay well for food that tastes better.

To meet that last (and richest) market, you want a design that requires as little owner effort as possible. The owner would lay down the robot and pour in some soil, but ideally do very little else other than insert modules and possibly harvest.

The Farmbot today has a seed planting tool and a watering tool. Let's look at other functions a farm robot might have:

• Because the robot knows very precisely where it put each seed, anything not in those locations is a weed. Knowing this offers various weeding strategies, including the ability to tackle each weed within hours after it sprouts. There could be very precision application of weed killers, and they could be placed with such precision they might be stronger than usual. Mechanical weed destruction and removal is also possible. The system would also know when it failed, and has to summon a human. Bosch makes a weed killing robot for larger farms.
• Simple hyperspectral cameras might eventually lead to super understanding of how plants are doing, and near-perfect estimation of ripeness, as well as amounts of feed and water to apply, again with full precision.
• Insect pests could be spotted immediately, and some of them dealt with. It is not even out of the question they could be burned with lasers, which of course is super cool.
• Animal pests (stealing the food) could be detected and harassed with motion, lights, sound or even that bug-killing laser. The robot could be a very superb scarecrow. Of course, netting could also be used on the garden since the human rarely has to access it.
• The soil could be tilled by the robot. Analysis of the soil may make more sense to do remotely but it could be a service.
• The system could tell you exactly when to pick every plant for perfection, or what the best plant to pick is when you want something. It might even be able to harvest certain plants with the right attachment and put them in a basket for you to collect.
• The robot could anticipate frosts, requesting the humans to put a cover over the garden and even applying heat.

For the non-gardening gardener, you would just order cartridges online with seeds, nutrients or weed killer, plug them in and let it run. Then eat whatever is at the peak of flavour. The app could also arrange trading with neighbours -- everybody likes being generous to neighbours with home produce. (Farmbot is open source but of course could make money from this business quite well.)

Over time, mass manufacturing might make this cheaper and more flexible. For example, eventually a free-roaming design could be possible that is of course much easier to install and could handle much larger plots of land. (It would need to go back to base to refill on water and electricity.) Knowing the garden so well (because it planted it) it could know where to put its wheels. It doesn't matter how slow it is, so long as it's quiet.

Vertical farming might be interesting. With a vertical farm on the wall, the robot might simply hang in front of the wall without even needing tracks, though it could not apply much force in that case.

Robots might even make practical something that started off silly -- indoor farming with LED light sources. The idea of taking even solar panel energy and using it to shine lights indoors is silly compared to having a garden outdoors or having skylights, but people have slowly been making that more reasonable, using purple LEDs (no light wasted on the green plants don't want) of high efficiency. Robots might be able to do even better, shining or concentrating light precisely on the leaves of plants so that little energy is spent lighting anything else. I have not done the math, but if anything can make this work, such precision might do the job.