Killing weeds with electricity is considered an alternative to using glyphosate, and tests show what the process can do – and what it can’t. Killing weeds with electricity is considered an alternative to using glyphosate, and tests show what the process can do – and what it can’t.
What is Glyphosate?
Utilized in agriculture, forestry, lawn, and garden care for combating the growth of unwanted plants, weeds, and grasses, glyphosate is the most widely used herbicide in the world. Glyphosate was created in 1970 by the Monsanto company and is one of the broad-spectrum herbicides that act by blocking an essential enzyme called 5-enolpyruvylshikimate-3-phosphate (EPSP)synthase, which is vital for plant growth.
As a definitive ban on the use of glyphosate looms on the horizon, many farmers are looking for alternatives to glyphosate and other chemical herbicides. One method that has so far been used more in organic farming is electrical weed control.
Control the weeds in three steps
The French Institut du Végétal (Arvalis) has tested the electric weed control method since 2018. The focus is on the effectiveness of weed eradication. The tests took place near the French city of Metz, using the Xpower device with the Electroherb process from the Zasso company.
The weeds were eradicated during tests at 2 km/h, 4 km/h, and 7 km/h. For comparison, the control plot was treated with glyphosate. After 37 days, the researchers examined how effective the procedures were. There were clear differences among cultures.
Good results in the rapeseed crop but poor in the wheat crop
While glyphosate only killed 45% of weeds in the fall canola crop, the electric process killed nearly 100% at all speeds and was significantly more effective. Also, glyphosate only managed 85% of the weeds in the spring pea crop, while the electric process killed over 90% of the weeds.
The situation was different for cereals. While glyphosate reliably removed all weeds in the wheat crop, the electric device achieved at best 20% effectiveness. In permanent pastures, in the case of clover and red clover, the electric method had almost no effect in the spring.
In autumn, however, the method performed better, at least for clover and red clover, with more than 80% of the plants being removed.
The slower the work, the more effective it is
Electrical voltage passing through plants and soil affects plant cells. This process will dry them out. The result depends on the plant species, available biomass, stand density, and humidity. In dry environmental conditions, care must be taken as there is always the risk of fire.
Tests show that lower speeds are significantly more efficient. The best results were achieved at a speed of 2 km/h. This is because the plants are exposed to the electrical charge for a longer time.
The following ground rules can be derived from experiments:
– weeds are easier to remove than grass;
– the higher the biomass, the less efficient the procedure;
– the procedure is more effective if the soil is moist;
– humidity, for example, dew, increases the efficiency of the procedure;
Costs of electric weed removal
A disadvantage of the method is a low speed, due to the low travel speeds and the working width of 3 m. In addition, the technology is significantly more expensive than glyphosate or tillage, with costs going up to 250 euros/ha.
To see how the method affected soil life, the researchers also calculated the earthworms in the plots and the microbial biomass. The measurements showed no negative impact of the electrical voltage on the earthworms and the amount of microbial biomass.