what operations should a ‘cultibot’ be able to perform?

The list of necessary operations might seem pretty straightforward. A robotic gardener or gardening system (more than one type of machine, each specializing in a subset of the overall range of operations) would need to be able to accomplish the same basic tasks as a human gardener: seedbed preparation, even if it's only a narrow hole through mulch and/or ground cover; planting, watering, weeding and/or suppressing weed growth; applying nutrients in one form or another; intervening to control animal pests and diseases if they threaten to become a problem; tracking the progressing ripeness of the crop and combining that information with the weather forecast to decide when to begin harvesting; and, of course, the harvest itself. Also, to get the best possible productivity from the land and the greatest benefit from the investment in a robotic gardener or gardening system, that machine or system should be able to start seedlings in a greenhouse and then move them out to the open field, inserting them through mulch and/or ground cover.

Then, too, there are other operations which are either optional or less commonly understood to be necessary: either collecting leftover coarse plant matter (corn stalks, tomato vines, and so forth) for centralized processing (grinding, optionally followed by anaerobic digestion producing methane gas, followed by aerobic composting) or simply grinding it into small bits in the field and leaving it where it falls, for mulch; limited relocation of soil to create and maintain a topology which slows the runoff of excess precipitation, without creating pools that persist hours or days after the latest storm has passed; relocating larger stones found in the soil to create permeable dams across grassed drainage ditches, where they can help slow water movement and help prevent it from cutting through the sod; and dredging muck from the bottom of surge ponds and distributing it over the field, to recover nutrients and prevent them from overloading any permanent ponds, much less passing downstream.

But, if you're going to have robotic machinery doing all of this, there are other operations you might want it to perform, operations which machines that have sensors and processors and well as effectors can relatively easily be made capable of performing. Examples might include: keeping detailed records including when each seed was planted and what the soil temperature and moisture content was at the time, when the sprout emerged from the ground, and how fast it grew; monitoring each plant for early signs of infestation, disease, nutrient deficiency or toxicity, waterlogged soil, and so forth; and targeted pruning to control infestation and disease without drastically reducing leaf area.

In the next installment, I'll begin to address design options and mechanical details relating to making machines capable of performing the basic operations listed above.