Abstract
In the boreal zone of Europe, differences between the four seasons are considerable. Also, the within-season variation in climatic conditions is substantial. This has many impacts on agriculture that are exceptional when compared to any other environmental zone in Europe. All the meteorological data were based on weather observations made by the Finnish Meteorological Institute. Likelihood (%) for soil frost (≤ 0 °C at 20 cm soil depth) at nine weather stations, and late snow cover (> 1 cm) (10 km × 10 km grid) were estimated for late spring. Probabilities (%) of night frost at the ground surface (March-September) were calculated at nine weather stations by frequencies of the lowest observed night-time temperature: a) between –2 and –5 °C (mild), b) ≤ –5 °C (moderate) and c) ≤ –9 °C (severe). Also, the probabilities (%) of night frost in mid-summer were estimated (≤ –1 °C for at least five hours). Furthermore, a significant shift from mild to below-freezing conditions was measured in winter as a period of at least ten days with daily maximum temperatures above 0°C followed by at least a 10-day period with daily mean temperatures below –5°C in order to characterize high fluctuating winter conditions. All these except late snow cover constitute high risks to crop production. Deep soil frost may postpone sowings, while in advanced springs, night frost may cause damage. For winter crops and perennials, shifts from mild to cold spells outside the growing season are particularly detrimental. Again the data may have many other applications beyond the assessments highlighted in this paper.
Highlights
Finland’s climate is characterized by distinctly different seasons: the winter mean temperature remains below zero in the whole country, while in summer mean temperatures are typically approx. 20 °C higher (Pirinen et al 2012).These climatological extremes take turns through the transition seasons
Likelihood for the risk of late soil frost at a 20 cm soil depth was low (≤ 2%) at the locations in the southern and south-west coastal prime production region in early May, but increased towards the northern dairy region, where it ranged e.g. from 5 to 53% at around 8 May ‒ until the risk virtually shifted after mid-May (Table 1)
Similar shifts from the southern, coastal locations to inland-northern locations were evident for the probability of late snow cover: by 5 May it was < 10 % for the former locations, while up to 30‒40% in the latter ones (Fig. 1)
Summary
Finland’s climate is characterized by distinctly different seasons: the winter mean temperature remains below zero in the whole country, while in summer mean temperatures are typically approx. 20 °C higher (Pirinen et al 2012).These climatological extremes take turns through the transition seasons. The thermal growing season, i.e., the time when the daily mean temperature exceeds 5 °C, starts at the end of April according to the long-term mean in the southernmost regions of Finland and approximately one month later in the northern parts of the country. Long days typical of high-latitude growing seasons substantially enhance the rate of development of many crops (Peltonen-Sainio and Rajala 2007), which again means that the time window is narrow for practically all the field operations to gain the optimal outcome and efficacy. This again may be further challenged by variable and unfavourable weather events
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
