Now you might wonder why I'm referring specifically to 'Biological' agriculture, rather than just refer to agriculture in general; allow me to explain.
The loss of soil through erosion, and the loss of fertility and the capacity for water retention in what remains are both reaching crisis proportions, with the result that it will become increasingly difficult to maintain yields on much of the land currently in production. Compounding this is the prospect of a world population that may be brushing up against ten billion by the middle of this century, the spread of urban areas onto land previously used to produce food, and climatic changes that dictate changes in what crop is grown where.
Moreover, while the number of people afflicted by starvation is actually falling, the percentage of people affected by malnutrition is on the increase. Over the last few decades, we have been catching up with the demand for calories, even for protein, but falling behind in terms of a well-rounded diet. If the goal is to feed everyone to a high standard, then we are not on track to achieve it, even without the further loss of production capacity.
There are countertrends, of course. Consumer cooperatives, urban farming, and direct connections between market farmers located near cities and consumers within them all work to narrow the gap between what is available and affordable through conventional channels and that well-rounded diet. On the downside, local production is even more seasonal than are conventional channels, which regularly bring in goods harvested unripe to help them survive long-distance transport, selling these at a premium in the off-season. It remains to be seen how much of that gap can be spanned for how many how soon. There are many working to push the envelope as far as it can be pushed, but habit and an avalanche of advertising stand in the way of rapid change.
One specific countertrend where robots are already making an inroad is in the production of leafy greens under artificial light in urban factory settings. Because these are controlled environments with repetitious geometries, it is relatively easy to make machines operate within them. No doubt this trend will continue to make headway, branching out into other types of produce at it proves practical to do so, but, at least for the near term, it will probably be limited to crops that are shade tolerant, not requiring intense light, and even the seed for these will continue to be produced outside.
If these trends continue to gain momentum, they may take some of the pressure off rural food production, even with a growing population. Nevertheless, we will continue to need that rural production for a long time to come, for the foreseeable future, so we'd better be thinking about how we can protect and improve the productivity of the land we depend upon.
This is where both biological agriculture and robots come in. In recent times, while what constituted conventional agriculture has been growing in scale and increasing its use of industrially produced fertilizers, pesticides, and herbicides, the practice of biological agriculture has mostly happened at the scale of gardens worked by hand, and, for the people working these gardens, this is quite often simply a matter of using traditional methods passed down through generations, which aren't necessarily optimal, but which are generally less destructive than the methods that have become conventional in the developed world. Unfortunately, such traditional methods only scale with the number of hands available to perform them, and the trend has been for people to leave this way of life for the cities – a new wave of emigration with each new war or environmental catastrophe – with the land they had been tending falling into the hands of larger scale farmers using more conventional methods. (Take a minute to consider for whom this migration off the land might be convenient.)
Using conventional equipment, the methods of biological agriculture don't scale without compromise. Where you might pull weeds by hand and avoid tillage in a small garden, as the size of the farm goes up the temptation to use wholesale methods, tillage or herbicides or both, can become overwhelming. Tillage exposes the soil to erosion, and herbicides can mess with soil microbiota, leach into ground water, are washed away with runoff, and remain present in trace amounts in the food produced, also true for pesticides and fungicides. Granted that it's not really fair to lump all such products together as being destructive – some are far more so than others – but on balance it's better to avoid their use if a practical alternative exists, and, if they must be used, to use them as sparingly as possible, through precise application.
What's needed is equipment capable of using methods which are functionally equivalent or superior to what a gardener doing the work by hand might use, and can do so without a human operator, so the number of such machines in operation is not limited to the number of human operators available. Perhaps surprisingly, the second of these requirements frees equipment manufacturers to opt for smaller rather than larger designs, both reducing the amount of damage one might do if it malfunctions and enabling economies of scale not available to equipment produced only in the thousands of units per year.
What may also be surprising is that, while equipment designed to work thousands of acres doesn't scale down for use in gardens, equipment designed for use in gardens, if it can be trusted to operate autonomously, will quite happily scale up to thousands of acres, bringing with it a transformation of the methods in use.
In the absence of ready examples to point to, it's hard to know how the economics of this transformation might work out. While the smaller devices would each be far less expensive than, for example, a modern tractor, many more of them would be needed, so equipment cost might actually be higher. On the other hand, if they are doing the mechanical equivalent of weeding by hand, and not consuming diesel fuel to power pulling implements through the soil, the cost of other inputs will be reduced. Also, their use may enable the cultivation of higher value crops that can't easily be produced by bulk methods.
Improving technology and techniques will undoubtedly, at some point, tip the balance in favor of using smaller, autonomous machinery, so that farms which do so are more profitable than those that do not, and once that happens further development will be driven by a rapidly growing market.
The smallholders alluded to above will be among the biggest beneficiaries of this trend. Much of the technology developed for conventional agriculture has only made their lives harder, by driving down the prices of commodity crops like maize and wheat. But the development of small, autonomous equipment, well suited to small plots and crops that aren't so easily produced using bulk methods, would make it possible for them to use more intensive management of the land they have, and spend less time doing it.
Another class of beneficiary is plant breeders, the people working to develop crop varieties that are better at competing with weeds, are more resistant to pests, are more hardy under a wider range of environmental conditions, produce higher yields in poorer soil with less fertilizer, and, as if all that weren't enough, are also more nutritious. This is tedious work*, and machines capable of performing detailed field operations autonomously would dramatically improve its effectiveness, in particular because land in active production and the machines tending that land could all be enlisted in the effort, by simply including some additional code in the programming of those machines. That increased effectiveness could help insure the availability of nonproprietary seeds which a farmer can save from one crop to plant the next without the next generation being far less productive than the original seed, and without being sued for doing so.
Next I'll get into some specifics of just how robots might perform such detailed field operations.