Crop rotation

(center pivot irrigation in Nevada – iPhone)

I’ve been travelling a fair bit (thankfully for pleasure) which has meant a fair amount of time in the sky. Flying back from Minneapolis meant a trip over the deserts of Nevada and Arizona, which never fails to impress. The vastness and emptiness is a whole new experience for someone who grew up in overpopulated Europe. America is also the first country where I’ve encountered center pivot irrigation systems, and the resulting geometric landscapes. Just as medieval ploughs created ridge and furrow topography, and cornfields are divided up by the width of a combine harvester, the geometric dimensions of center pivot irrigation are defined entirely by the physical characteristics of the tool.

A typical center pivot irrigation system takes around three days to complete a full circle, based on the radius of the irrigation arm. Logic states that if we extend the arm far enough this cycle could be weeks or even months. Multiple arms radiating out across the circular field could ensure the crop receives the correct hydration, with the final arm being a harvester, followed by a sweep of the seeding arm for the next season’s crop. Feed, pesticides and other tending could be added by extending another arm wherever needed. Rather than being an Archigram walking city, this could be a pirouetting city, rotating on it’s axis once per crop cycle. When viewed from above, the entire agricultural process would be visible as the face of a clock. Fallow periods could be created by missing out three or four hydration arms. Different crops could be grown in different orbits creating a food ‘solar system’, with each planetary orbit progressing at different speeds depending on the particular needs of that crop. One thing’s for sure: if man ever colonises other planets, his fields will be circular.

(more on center pivot irrigation here)