Sunday, April 05, 2015

Drought & desertification: Robots can help

A NYTimes article published April 2nd, Mapping the Spread of Drought Across the U.S., leads off with an animated map supplied by the National Drought Mitigation Center, which shows the spread of drought conditions across the contiguous 48 states since late fall, 2014.

From that article: “Droughts appear to be intensifying over much of the West and Southwest as a result of global warming. Over the past decade, droughts in some regions have rivaled the epic dry spells of the 1930s and 1950s. About 37 percent of the contiguous United States was in at least a moderate drought as of March 31, 2015.”

There are two major ways in which robots can help with the effects of climate change, whether permanent or cyclical, upon food production.

Most immediately, robots can operate indoor production facilities using artificial light to produce high value, quickly maturing crops requiring moist environments. To operate most efficiently, that artificial light would be predominantly red and blue, since green light is mostly reflected away by plants, which is why they appear green to us. This might prove a stressful environment for human workers, but robots won't care.

The other way in which robots can help is in dry fields under the hot sun. This can be as simple as reflective umbrellas, nets, or horizontal shutters that shade the ground from the mid-day sun, but uncover it again in the late afternoon to allow cooling radiation into the night sky. Robots could also maintain drip-irrigation systems or make daily rounds to inject water into the soil near root crowns.

In principle, they could also perform planting, weeding, pest control, pruning, harvesting, and deal with plant materials left behind after harvest, and do it all working a mixture of annuals between and around standing perennials, although much of the technology needed for such a scenario remains to be developed.

On the other hand, given that level of utility, much becomes possible that currently is not. The weight of machinery can be kept entirely off of productive soil, rendering it more capable of holding water. Mulch can be applied at any time. When expected precipitation fails to materialize, plants can be pruned to reduce their leaf area and the amount of water they require. Windbreaks can be installed surrounding relatively small patches of land, in a manner not conducive to working them using tractors and conventional implements, but affording much better protection from drying winds as well as providing a secondary crop of woody fiber and habitat for wildlife. If planted in low berms, those windbreaks would also help to keep what moisture there is in the fields and eliminate water erosion.

The benefits of such technology aren't limited to coping with drought, of course, but given that drought is likely to be a widespread, persistent problem, it can help to keep marginal land, which might otherwise turn to desert, in sustainable production, and perhaps even help to reclaim some land that has already been lost to desertification, beginning with the construction of windbreak fences (like snow fences) to accumulate wind-blown dust that will become the berms into which living windbreaks can be planted.

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