The new is well-forgotten old. And since the world develops in a spiral, then at its next turn, mankind steps on the already familiar “rake”. Or he discovers the answer to another “problem of the decade” in a warehouse of long-forgotten equipment. A similar “reincarnation” occurs in the field of plant protection. Fire cultivators are a good example. That is, hand or wheeled implements operating on the principle of a gas burner. Here choose the best weed torch.
A kind of “flamethrower” for weed control is a wonder weapon of the 1930s. Nevertheless, the simplicity, reliability, and environmental safety of fire cultivators have proved to be in demand in the 21st century.
Killing weeds with fire and steam is more efficient and less harmful to the environment than traditional methods of weed control that involve mechanical tillage (cultivation and harrowing). “Flamethrower” damages weeds, but practically does not affect the physical, chemical, and microbiological characteristics of the surface layer of the soil. Heat treatment allows you to control weeds in the aisles of growing crops / perennial crops. The use of a fire cultivator as an additional means of control eliminates the need for manual weeding. Some crops are quite resistant to short-term heating, so there are technologies in which a fire cultivator “burns out” weeds not only in the aisles but also in the rows of the crop.
But, as they say, you have to pay for everything. Thermal weeding is more expensive than alternative mechanical weed control. For “burning out” weeds, the consumption of fuel (liquefied natural gas) is from 20 to 80 l / ha, and the productivity of the units usually does not exceed 2-3 ha / hour. Therefore, it is advisable to use a “flamethrower” on the field in situations where other methods of weed control are not effective or for some reason are prohibited.
For example, when growing “organic” products. Thermal weeding is cheaper than manual weeding, but the equipment is not cheap, and the cost of LPG reaches 50-80 kg/ha (Ascard, 1990; Nemming, 1994).
“Organic” farming brings back “flamethrowers”
Fire cultivators were used in the United States from the late 1930s to the mid-1960s on row crops (cotton, corn, sorghum). The widespread use of selective (selective) herbicides led to the fact that for 30 years (1965-1995) thermal weed control technologies were perceived as an anachronism. This can be easily explained by comparing, for example, data from Canadian studies (Lague C., Khelifi M., 2001). With continuous herbicide treatment of maize crops, labor costs are 0.29 man-h / ha, and 2 cultivation of row spacing + a fire cultivator require six times more – 1.923 man-h / ha.
The return of “flamethrowers” to the fields began in the mid-1990s, after the popularization of “organic” farming. Fire cultivators have proven to be a successful alternative to herbicide application and mechanical / manual weeding. Thermal action allows you to control not only weeds, but also pests. Therefore, when growing potatoes in the United States, for example, fire cultivators are also successfully used to destroy the Colorado potato beetle.
Fire cultivators produced since the 1990s differ from those of the mid-20th century. They are much safer and more convenient to operate, more precise in setting and use fuel more economically. Early models of fire cultivators used petroleum products (kerosene, naphtha, etc.) as fuel, modern “flamethrowers” use liquefied natural gas. Equipment for thermal weed control is produced not only in the USA, but also in the EU countries (Germany, Holland, Sweden, Denmark, Great Britain). Experimental data and mathematical models are used in the design of fire cultivators. Bertram (1994), for example, developed the thermodynamic principles of thermal weeding. Douzals et al (1993) and Storeheier (1994) also had a hand in the theory of fire cultivator design. It was found, for example,
At present, fire cultivators are not produced in the countries of Eastern Europe and the Russian Federation and are practically not used. Nevertheless, at the end of the 1970s, the KO-2,4 fire cultivators was produced in the USSR. The cultivator worked on natural (propane-butane) gas, which was in two tanks with a capacity of 372 liters. A full charge of the tanks at a flow rate of 40–60 liters of gas per hectare was enough to process 5–6 hectares. The KO-2.4 cultivator was fixed on the frame of the DT-24-3 or T-28 5 tractors, the productivity was approximately 1 hectare/hour.