CHAPTER EIGHTEEN

China’s Electric Greenhouses

The largest electroculture program in history is not in the past. It is running now.

The program

In 1990 the Chinese government began funding trials of high-voltage electric fields in vegetable production. The work was led for many years by Liu Binjiang, an agricultural scientist in the northeast of the country. In September 2018 the South China Morning Post reported that the Chinese Academy of Agricultural Sciences and other state institutes had released findings covering nearly three decades of study, in regions from the Gobi fringe of Xinjiang to the Pacific coast.

By that report, greenhouses with a combined area of more than 3,600 hectares, almost nine thousand acres, were taking part. Bare copper wires were strung about three meters above the crop and charged with pulses of up to fifty thousand volts. The current was said to be a few millionths of an ampere, and the electricity consumption about fifteen kilowatt-hours per hectare per day, a trivial amount.

The reported results

The figures reported were these:

• vegetable yields higher by 20 to 30 percent;
• pesticide use lower by 70 to 100 percent;
• fertilizer use lower by more than 20 percent.

The area under treatment was said to be growing by a thousand hectares or more each year, increasingly with private money. Liu was quoted as saying there was no plan to electrify all of China’s four million hectares of greenhouses, because the equipment cost too much for most farmers, and that his team was working on a small all-in-one growing chamber for household use.

How to read this

This is, on its face, the strongest modern evidence that powered electroculture works, and it deserves both respect and care.

In its favor: the scale is large, the duration is long, the method is the classical Lemström and Blackman system, the yield figure matches what Blackman found a century earlier, and private growers have been paying for installations with their own money, which is a kind of evidence that reports alone are not.

The pesticide result is also physically sensible. A high-voltage discharge in an enclosed space charges dust, spores and fine water droplets and drives them out of the air, the same principle used in industrial electrostatic air cleaners, and produces small amounts of ozone and ions that suppress microbes. Cleaner air in a humid greenhouse means less fungal disease. Some of the yield gain may come simply from healthier plants.

The cautions are these. What reached the outside world was a newspaper account of an announcement by the program’s own scientists. I have not found the underlying data, with controls and statistics, published in full in the international peer-reviewed literature. Some of the installations combined the electric field with artificial lighting, which would raise yields by itself. And the results are from greenhouses, enclosed and controlled, which is a very different thing from an open field or a backyard bed.

The fair conclusion: there is substantial, though not rigorously published, evidence that high-voltage overhead fields can raise vegetable yields and reduce disease in greenhouses. This is good evidence for powered electroculture in protected cultivation. It is no evidence at all for an unpowered coil.