Moisture sensors planted throughout almond nut groves keep track of what is going on in the soil. They send their results to a computer in the cloud (the network of servers that does an increasing amount of the world’s heavy-duty computing) to be crunched. The results are passed back to the farm’s irrigation system—a grid of drip tapes (hoses with holes punched in them) that are filled by pumps.
The system resembles the hydroponics used to grow vegetables in greenhouses. Every half-hour a carefully calibrated pulse of water based on the cloud’s calculations, and mixed with an appropriate dose of fertiliser if scheduled, is pushed through the tapes, delivering a precise sprinkling to each tree. The pulses alternate between one side of the tree trunk and the other, which experience has shown encourages water uptake. Before this system was in place, Mr Rogers would have irrigated his farm about once a week.
Farms that grow high-value but thirsty crops like pistachios, walnuts and grapes, are at the leading edge of this type of precision agriculture, known as “smart farming”.
It is not only fruit and nut farmers who benefit from being precise. So-called row crops—the maize and soyabeans that cover much of America’s Midwest—are being teched up, too. Sowing, watering, fertilising and harvesting are all computer-controlled.
By 2050 agricultural production will have to rise by 70% to meet projected demand.
Farms, then, are becoming more like factories: tightly controlled operations for turning out reliable products, immune as far as possible from the vagaries of nature. Thanks to better understanding of DNA, the plants and animals raised on a farm are also tightly controlled. Precise genetic manipulation, known as “genome editing”, makes it possible to change a crop or stock animal’s genome down to the level of a single genetic “letter”. This technology, it is hoped, will be more acceptable to consumers than the shifting of whole genes between species that underpinned early genetic engineering, because it simply imitates the process of mutation on which crop breeding has always depended, but in a far more controllable way.
The best aerial monitoring solution is to integrate aerial and satellite coverage. That is what Mavrx, also based in San Francisco, is trying to do. Instead of drones, it has an Uber-like arrangement with about 100 light-aircraft pilots around America. Each of the firm’s contracted planes has been fitted with a multispectral camera and stands ready to make specific sorties at Mavrx’s request. Mavrx’s cameras have a resolution of 20cm a pixel, meaning they can pretty much take in individual plants.
Precisely monitored greenhouses are cutting the growing time by 30-50%
Precise greenhouse growth has reduced the cycle for coriander from 21 to 14 days. But tests suggest that the system also works for other, chunkier crops. Carrots and radishes have already been successfully grown this way, though they may not command a sufficient premium to make their underground cultivation worthwhile. But pak choi, a Chinese vegetable popular with trendy urbanites who live in inner-London suburbs like Clapham, is also amenable. At the moment growing it takes five weeks from start to finish. Get that down to three, which Mr Dring thinks he can, and it would be profitable.