Heat waves lead to yield losses!

A new study revealed that crop loss related to droughts and heatwaves tripled in the last 50 years! What will it be like in the summer of 2021?

Heatwaves cause yield loss

In front of us lies the summer 2021: how will it be?
Rather wet and cold or hot and dry again?

The long term weather forecasts for this summer predict both: cold temperature and stormy weather for Northern and Western Europe and very hot and dry weather for Southern and Eastern Europe. (Fig. 1)

 Long term weather forecasts for this summer predict both: cold & stormy and hot & dry

Fig. 1: Long term weather forecasts for this summer predict both. (Source:

More and more heatwaves, crop loss tripled in the last 50 years

In Europe, crop loss due to droughts or heatwaves tripled in the last 50 years!

32 droughts and 61 heat waves were recorded in the European Union between 1961 and 2018 (EM-DAT extreme weather disaster database). Do these events cause yield loss? And if yes, how much? 

The new European-wide study Brás et al. 2021 (in press) says:

  • YES! Droughts and heatwaves cause significant crop loss!
  • YES! The magnitude of crop loss has been rising since 1961!
  • YES! The frequency and severity of droughts and heatwaves is rising too!

While total crop loss related to droughts and heatwaves was on average 2,2 % between 1964 and 1990, it rose to an average of 7,3 % between 1991 and 2015. Hence it was tripled in a few decades! (Fig. 2). The average crop losses are higher for cereals, probably because they are rarely irrigated. This suggests that droughts and heatwaves are particularly harmful to rain-fed crops.

Percentage of crop loss after droughts and heatwaves in the EU

Fig. 2: Percentage of crop loss after droughts and heatwaves in the EU. Cereals comprise wheat, barley, maize and other cereals. Non-cereals comprise oil crops, olives, vegetables, grapes, sugar beet, and others). Numbers from Brás et al. 2021: Severity of drought and heatwave crop losses tripled over the last five decades in Europe.

Droughts and heatwaves will become more frequent

Many climate models agree that summer dryness will increase in the future, with longer and more intense heatwaves and droughts (Fig. 3, EASAC 2013, IPCC 2012, Christidis et al 2015), including severe multi-year droughts in the Mediterranean region (Guerreiro et al 2017). The agricultural losses associated with droughts and heatwaves are therefore expected to further increase in the future (Brás et al 2021).

Projected change in meteorological drought frequency

Fig. 3: Projected change in meteorological drought frequency.

The common aim will be to mitigate the consequences of these more frequent and severe droughts as much as possible by increasing the drought resilience of our crops, searching for alternative crops, or also by supporting the standing crop as best as possible within the range of its specific potential.

What can AMALGEROL / AMALGEROL ESSENCE do against drought stress? 


  • increase root system (length and density), plant has more access to water
  • improves soil structure, water can infiltrate better into the soil (no crust)
  • water is stored in the soil (alginate) and due to higher humus content (soil health, soil life)

cure after drought:

  • osmotic adjustment: cells accumulate „osmolytes“: amino acids, amins, sugars, etc.
  • antioxidants help to scavenge ROS (free radicals that damage plant cells)


Is it worth using it?

The average crop loss due to droughts and heatwaves between 1964 and 2018 was 9 % in Europe (Brás et al 2021).
9 % less yield - depending on productivity and price - roughly corresponds to a deficit of 100 €/ha in wheat and 120 €/ha in corn.

YES! AMALGEROL is worth it!

With as little as two applications of 2 - 3 l/ha AMALGEROL / AMALGEROL ESSENCE significantly strengthen plants against drought and heat stress


Which crops can still benefit from an application?

Grapevine, Pome fruits, Stone fruits & Citrus fruits: 2 to 4 applications between end of flowering and beginning of ripening (colouring of berries/fruits)

Potato: 3 applications between beginning of crop cover and 50 % tuber size 

Sugar beet, other root and tuber crops: 3 applications between crop cover and end of beet root growth

Vegetables, melons: during the entire vegetation period


Do you also want to prevent yield losses?
Our team will help you to take precautions against drought or to regenerate the plants in case of drought in order to secure the yields.

Your Hechenbichler team


Science and practice

are the drivers for constant advances in the development of our products.