Polski
Snowy and cold winter – is it a thing of the past?
Winters of the 1970s, 1980s. or 90. The last century was characterized by the occurrence of snow in the winter season. It usually began to rain as early as November, in December forming a permanent cover that did not disappear until February and March of the following year. In the spring, as a result of increasingly warmer temperatures, the snow melted, providing a valuable source of water resources for plants starting to grow. Nowadays, year by year, we see this situation less and less often.
Will climate change force a new approach to agricultural production?
Changing climate characteristics through rising temperatures, including in winter, are resulting in less frequent and less abundant snowfall and accelerating snow melt. And it is the water from the snow that has been and should continue to be the most important spring source of moisture supply to the soil.
According to climatology experts, the consequences of climate change, including increasingly warmer air temperatures and thinner snow cover, will significantly affect agricultural production in the future, mainly crop yields. Climate projections indicate that by 2050. The water needs of plants will increase by approx 30%. The observed climate change is likely to increase the frequency and intensity of water shortages and droughts, further drying (stepping) of soils, or changes in the length of the growing season. If the predictions become reality, crop yield losses are expected to increase. Therefore, the situation we are seeing should be an impetus to take adaptive measures now to reduce the negative effects of global warming.
What is snow for agriculture?
Snow is not only an important parameter describing the characteristics of the climate but also a factor affecting the life processes of plants. It mitigates temperature fluctuations in the plant environment, which is important especially for shallow-rooted species. In winter, when the vegetation process dies down, the snow cover provides an insulating layer to protect plants from low temperatures and wind. It also prevents frostbite. It is assumed that the best insulation layer is the thickness/height of snow above 10 cm. It is also beneficial for it to gradually dry out when exposed to sub-zero temperatures. This prevents it from becoming a clumped, icy layer, thereby cutting off air access. That’s why the presence of snow cover and the presence of adequate temperatures are so important for plants, especially oziminals during the winter.
Of course, do not forget that too thick, long-lasting, icy snow cover is harmful to plants – under the snow and ice cover they can “suffocate”.
Crop production is vulnerable to water shortages, including snow shortages in the winter season.
Agriculture, especially crop production, is the sector most vulnerable to water shortages. Winter snow cover is both a source of spring moisture supply to soils and a countermeasure against wind erosion of soils. The water from the spring melt, known as the “water melt” post-winter water, is of great importance, especially on light soils, determining significantly their productivity.
As a result of a warming climate, the growing season is lengthening, which is likely to increase the number of days with water and heat stress for plants. The length of the growing season is an agroclimatic indicator used to assess production potential in agriculture. In practice, this indicator is used for planning field work, including determining optimal sowing or fertilization dates.
In addition, the number of days with snow cover is likely to decrease, as well as its thickness. In central Poland, where the best production results have been obtained so far, with unfavorable precipitation conditions, including decreasing snow cover in winter and early spring, the effects of rising temperatures and evapotranspiration could become a significant problem for agriculture, especially crop production.
Likely consequences
As a result of the described changes, on the one hand, thermal conditions for the cultivation of thermophilic crops will improve, on the other hand, the earlier onset of the growing season may increase the risk of losses as a result of the increasingly observed late spring frosts.
Spring crops that are at the germination and emergence stage (e.g., sugar beets, legumes), sown in March and April, are sensitive to inadequate soil water levels and late spring frosts. Lacking sufficient water in the soil, severely damaged and frozen sprouts have no opportunity to regenerate. If the situation escalates, over time the production of the above crops will require screening or liquidation.
The likely consequence of the described changes will also be an acceleration of the growth rate of some weeds, which will result in greater agricultural nuisance. The country has seen an increase in the population of warm-season weeds and better overwintering of those that have so far tolerated winter poorly. Therefore, it can be a problem to control them in crops with low soil moisture.
In addition, mild winters, little snow cover, and higher summer temperatures will favor the development of crop pests. There may be an increase in the activity of previously identified pathogenic fungi and pests. In addition, there is a risk that new warm-blooded pest species, including invasive or quarantine organisms, will emerge. Increasingly warmer and less snowy winters favor thermophilic species that overwinter and thrive during the warm growing season, including adjusting their biology according to weather conditions. Changes in the physiology of pest organisms and the expansion of their range may also be observed, including the migration of thermophilic species to the north of the country.
