How to protect your plantation from frost damage, a short novel about spring frost.
In biology, there are animals who are winning the race against frost. These are the wild ducks who move their own water all night long and don't let it freeze. They don't kick the membranous ice back under the water to melt, but move the water along with its deeper layers, and although this larger mass cools together: the surface doesn't freeze. The hunters have a unique word for it.

For all the spring frost damage : " above 2m we have about 30% crop left", or "we got half crop but almost nothing on the lower 1.5m", "we have just about enough apples left but lots of industrial quality" : after all these will be the end of season sayings, sound familiar?

An area of 3.3ha at a height of 3 metres contains 100,000m3 of air. This space contains the majority of our crops. When this air mass cools to -7C, it causes total frost damage in flower. Do you know how much energy is then lost from these 100,000 m3 of air? : 20 litres of petrol. 20 litres of petrol would heat 3.3Ha of enclosed plantation air to 0C. Unbelievable? There are 3 million times that much surface area in Hungary and multiplying that by the sunset the night before is a pretty big number.

Inversion: imagine a spring day when the ground is 25 °C and the air is 14-15 °C. The ground warms the few centimetres of air directly above it, which rises because it is warmer and lighter. This ascended air mass gains heat throughout the day and is warmer at 10-30 m above the ground than at the lower 0-10 m. The sun sets in the evening and the soil is left alone, without irradiation. It loses daytime heat very quickly, and by 21.30 in the evening the surface can be as low as -9 °C. It constantly cools the 0-5m air field immediately above it, but the good insulating properties of the air mean that the damage moves up slowly. The updraft air, still warmed by the ground during the day, is now being cooled from below: it is trapped. Its energy surplus came from the sun that warmed the soil, but now, at night, it is being left to cool it. This trapped layer is the INVERSE. In spring it can be discovered at heights of 4-30m. It has an average heat gain of 3-5 °C degrees.

Imagine a pine forest with a pine needle at the end of its needle leaves, where the freezing points produce a multitude of -5 °C energy states. This moves inwards towards the branches due to the water content of the plant. Such freezing points include the tip of a grass blade, the end of a barbed wire, but also the bud, petal, stamen and pistil. Doing nothing more than blowing these frost points out of place would go a long way to improving the crop. To this the popular wisdom says: "...only the wind should not stop!" This artificial wind does not cause a measurable increase in temperature, but it does cause a harvestable crop: YES. We prove frost protection with °C degrees, but the crop is the product. The Juventus coach said: against Barcelona, we don't want to win possession, we want to win a match.

You have certainly pushed a ping-pong ball underwater. This is how warm air rises when it enters a cold medium. Unfortunately, this is also the case with small temperature differences, e.g. cigarette smoke in a room.

The crops that survived the spring frost suggest that not much was missing to produce more. Varieties, soil patches, edge row, ditch, etc., behave differently. In hindsight, a few tenths of a degree would have helped a lot. To sum up: spring frosts do not occur at a drastic pace, there is time to protect. The frost-heated plantation lost its measured energy surplus in 24 minutes after the F-AirGo V2021 was shut down. It should be back to the same place in 15 minutes max.

The effectiveness of the defence may be based on the repeated small-scale energy input. The formation of an air current is a significant advantage. With stationary and towed wind turbines, the thermal energy of the systems present in the inversion or flowing into the air layer of the inversion can be used for protection: (tractor exhaust, sawdust stove, antifreeze candle, coke bucket, fog dragon, frostbuster, etc.). ) Irrigated area, short cut ground cover, plant condition all contribute to crop protection as a combined technological element.
Endre Farago
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