Survey of Potato Growers’ Perception of Climate Change and Its Impacts on Potato Production in Germany, Switzerland, and Austria

Abstract

Among climate-change related effects, drought, heat, and waterlogging are the most important adversely affecting the production of potatoes in Europe. As climate change progresses, agricultural practices must adapt to maintain potato yields. This study is based on a European-wide survey. It presents potato growers’ perception of climate change, its impact, and possible adaptation strategies, focusing on the results from Germany, Switzerland, and Austria. Potato growers strongly agreed that climate change had affected their potato production in the last ten years, as indicated by 98% of German and more than 90% of Swiss and Austrian respondents. Drought caused the most severe impact, and to varying extents damage was caused by heat and the occurrence of pests and pathogens. The most preferred adaptation measure was the planting of adapted varieties. In line with the comparably low access to at least partial irrigation that Austrian potato growers reported, Austria appeared to be the country most affected by drought. Other more pronounced challenges were late spring frost, flash floods, and soil erosion. The study highlights and discusses specific differences between the countries, as well as between conventional and organic potato production based on the Austrian responses. The results underline that to successfully develop effective climate change mitigation strategies, country-specific and local challenges and needs should be considered.

1. Introduction

Potato (Solanum tuberosum L.) is one of the world’s most important food crops, alongside wheat, rice, and maize. In 2020, 53 million tons of potatoes were produced on 1.5 million hectares of land in the European Union (EU), which accounts for approximately 1.5% of the total arable land [1]. The organic farming sector represents only a small fraction, accounting for only 2.4% of the potato cultivation area within the EU [1,2]. The DACH region, referring to the German-speaking Central European countries Germany (D), Austria (A), and Switzerland (CH), has a long-standing tradition of potato cultivation and consumption. These three countries account for 21% of the potato growing area in the EU, including 44% of the organic potato growing area [1,2].

German citizens display a remarkable affinity for potatoes, exemplified by an estimated average consumption of 59 kg per person during the 2020–2021 period [3]. Germany is the largest potato producer within the EU, contributing 12 million tons on 273,000 hectares, which accounts for approximately 22% of the production and 19% of the potato growing area in the EU [1]. A total of 4% of the potato growing area in Germany is organic [2]. The primary potato-producing German federal states are Lower Saxony (45%), North-Rhine Westphalia (14%), and Bavaria (15%) [3]. These regions benefit from favourable climatic conditions, with abundant precipitation ranging from 786 mm in Lower Saxony to 971 mm in Bavaria and average temperatures ranging from 8.1 to 9.6 °C [4].

In 2020, Switzerland’s per capita potato consumption averaged 46 kg [5]. The country produced approximately 489,000 tons of potatoes on 10,960 hectares in the same year, with 8% of the potato growing area being organic [1,2]. The major potato production regions in Switzerland are the cantons of Bern (34%), Vaud (17%), and Fribourg (14%), all located in the southwestern part of the country [5]. These regions receive a substantial average annual precipitation of around 1000 mm, with average temperatures hovering around 9 °C [6].

Austria is known for its versatile and popular use of potatoes in its cuisine. During the 2020–2021 period, Austria experienced its highest per capita potato consumption since 1995, reaching 61 kg [7]. Austria contributes approximately 1.7% of the total EU potato production on around 24,000 hectares, which corresponds to 886,000 tons [1]. It is worth noting that Austria has the second largest organic potato growing area in the EU after Latvia, with 16% of its potato growing area being organic [2]. The majority of the potato cultivation area (82%) is located in Lower Austria [8], which is situated in the northeastern part of the country (Figure S1). The climatic conditions in this region vary greatly. In the northeast, specifically in the Weinviertel and Marchfeld areas, the climate is hot and dry with an average annual precipitation of 510 mm and a temperature of 10.3 °C. In contrast, the northwestern part of the region, known as Waldviertel, experiences wetter and cooler conditions with an average annual precipitation and temperature of 710 mm and 6.8 °C, respectively [9].

Climate change affects agricultural landscapes and poses challenges to potato production. Heat waves, droughts, floods, and heavy rainfall have considerably impaired potato growth and yield worldwide [10,11]. Potatoes are typically cultivated in temperate regions, with optimal conditions being average daily temperatures between 18 and 20 °C and rainfall of 500 to 700 mm [12]. Due to their shallow root system, potatoes are relatively sensitive to water deficits in the soil, especially during critical stages such as stolonisation, tuber initiation, and yield formation [12]. Furthermore, increased temperatures and episodes of extreme heat have detrimental effects on potato growth, yield, and tuber quality [13,14,15,16].

Pests and pathogens are also major threats to potato cultivation. Changing climatic conditions can have an impact on population dynamics. High temperatures during spring and autumn can increase the reproduction rates of pests and pathogens by providing them with more time to grow and develop [13]. Wireworms, the larvae of click beetles, have been observed to affect potatoes, particularly under dry and hot conditions [17]. In the DACH region, potato crops are commonly affected by pests and pathogens such as the Colorado potato beetle, aphids, Phytophthora infestans (causing late blight), and Alternaria solani (causing early blight) [18,19,20,21].

Based on an EU-wide survey conducted as part of the Horizon 2020 project ADAPT (Accelerated Development of multiple-stress tolerant Potato, https://adapt.univie.ac.at/, accessed on 6 April 2024), this article focuses on the results of Germany, Switzerland, and Austria. It describes environmental conditions, local perspectives, and potential mitigation strategies applied in potato cultivation within the DACH region. The Austrian perspective is analysed in more detail and includes different production methods such as organic, conventional, and mixed approaches.

2. Materials and Methods

2.1. Survey

The validation, selection, and definition of the relevant questions was performed by the project experts group, based on their experience with potato growers. The empirical data for this research were collected through an online survey with the online tool askallo. Participation in the survey was strictly voluntary, which should be considered when interpreting the results. The participants remained fully anonymous, and the source of the information could not be identified at any time. The survey was available online for five months from 4 December 2020 until 30 April 2021. It was distributed to the target group through institutions and companies that are in direct contact with potato growers. The survey was translated into ten different languages, which could be selected by the participant before starting the questionnaire: English, German, Dutch, French, Polish, Spanish, Bulgarian, Slovenian, Serbian, and Greek. A total of 553 responses were collected from potato growers in 22 European countries, of which an overview is given in von Gehren et al. [22]. From this dataset, the responses, and an overview of the responses is provided. For this study, responses from Austria (n = 159), Germany (n = 79), and Switzerland (n = 53) were drawn from the dataset. This allowed for a detailed examination of regional similarities and differences due to the high response rate from these countries.

To evaluate the perception of climate change and the needs of potato growers, 19 survey questions were structured as follows (see Document S1): The first part of the survey assessed the growers’ local perceptions of abiotic stress factors that have occurred in recent years and their expectations of future impacts. Participants who confirmed that climatic changes affected their potato cultivation were asked to identify the specific factors that have shown an increased impact over the past decade. The second part of the survey assessed the potato growers’ choice of adaptation strategies to mitigate the effects of climate change. Additionally, the survey aimed to determine the potato growers’ preferred source of information for variety choice. Finally, the survey participants were asked to provide key background information such as production methods, acreages, experience levels, and age, while maintaining their anonymity.

2.2. Survey Participants Characteristics and Site Conditions

In order to outline the basis of this study, which is characterised by the responses of the voluntary participants, key data are presented below. More comprehensive information is given in Document S2. The high number of Austrian survey participants allowed for an analysis of the differences between conventional and organic potato production in Austria. In order to compare the results between the three countries and between the production type groups within Austria, we conducted chi-squared tests. The statistical analyses were carried out with R Statistical Software (version 4.3.2) [23]

In Germany, most respondents (95%) were conventional potato growers, 4% used organic cultivation, and 1% followed a mixed approach. The question on production targets was presented in a multiple-choice format, allowing for values exceeding 100%. The primary production targets were the starch industry (58%) and table potatoes (52%), followed by the processing industry for human consumption (35%), and seed potatoes (25%). The acreage for potato production varied, with only a few potato growers growing on less than 3 (4%) or 3–8 hectares (11%). Approximately one-third of respondents cultivated potato on acreages ranging from 9 to 20 hectares (28%) or 21 to 50 hectares (35%). The remaining respondents reported potato acreages of 51–100 hectares (11%), 101–150 hectares (1%), or over 150 hectares (9%). Nearly all survey participants (99%) had more than 5 years of experience in potato production, with only 1% having less experience. In terms of age distribution, most respondents were between 45 and 64 years old (59%), 14% were less than 34 years old, 22% between 35 and 44 years old, and 5% were 65 years or older.

In Switzerland, most survey participants (81%) were conventional potato growers, 8% were organic growers, and 11% followed a mixed approach. The primary production targets were table potatoes (66%), the processing industry for consumption (57%), and seed potatoes (30%). None of the participants produced potatoes for the starch industry. The potato acreages in Switzerland were comparably small, with many potato growers cultivating less than 3 hectares (21%), 3–8 hectares (38%), or 9–20 hectares (36%). Only a few of the Swiss participants had larger potato acreages of 21–50 hectares (4%), none had potato acreages of 51–100 hectares or 101–150 hectares, and 2% had more than 150 hectares. Almost all Swiss survey participants (94%) had more than 5 years of experience, with the remaining 6% having less experience. In terms of age distribution, most Swiss participants were aged between 45 and 64 years (66%), 13% were less than 34 years old, 21% were between 35 and 44 years old, and 0% were 65 years or older.

In Austria, 55% of the survey participants were conventional potato growers, 33% were organic potato growers, and 10% used a mixed farming system of both organic and conventional production. The primary production targets were table potatoes (91%), the starch industry (23%), seed potatoes (21%), or the processing industry for human consumption (17%). The farm sizes in Austria were relatively small, with many participants having potato acreages of less than 3 hectares (35%), 3–8 hectares (19%), or 9–20 hectares (26%). Some potato growers reported larger potato acreages of 21–50 hectares (13%), 51–100 hectares (5%), 101–150 hectares (1%), or over 150 hectares (1%). Most participants from Austria (85%) had more than 5 years of experience in potato farming, while 15% had less experience. In terms of age distribution, most of the participants were between 45 and 64 years old (55%), 20% were younger than 34 years, 19% were between 35 and 44 years old, and 6% were 65 years or older.

The primary production target for conventional Austrian potato growers was table potatoes (85%), followed by production for the starch industry (32%), the processing industry for human consumption (27%), and seed potatoes (19%). The potato acreages varied, with some growers cultivating less than 3 hectares (18%) and 3–8 hectares (18%). One-third of the potato growers had potato acreages ranging from 9 to 20 hectares (34%), 17% had 21–50 hectares, and 9% had 51–100 hectares. A few had 101–150 hectares (1%) or over 150 hectares (2%). Organic potato growers primarily produced table potatoes (96%), seed potatoes (25%), potatoes for the starch industry (11%), and potatoes for the processing industry for consumption (4%). Most of the organic potato growers surveyed in Austria cultivated less than 3 hectares (57%) or 3–8 hectares (21%). A total of 17% had potato acreages of 9–20 hectares, and 6% of 21–50 hectares. None of the organic potato growers had a potato acreage larger than 50 hectares.

3. Results

3.1. Impact of Climate Change on Potato Growers in the DACH Region

In Germany, 98% of survey participants reported that changes in climatic conditions had affected their potato production in the last ten years, whereas in Switzerland, 89%, and in Austria, 90% of surveyed potato growers indicated that they had noticed the impact of climatic change. Notably, the results showed a difference between conventional and organic cultivation practices, as 93% of Austrian conventional potato growers, but only 83% of organic growers, affirmed climate-change-related impacts (

Table 1. Do you believe that in the last 10 years, changes in climatic conditions have affected your potato production? Responses from German (D; n = 79), Swiss (CH; n = 53), and Austrian (A; n = 159) potato growers. Responses from Austrian potato growers are divided into conventional (Conv.; n = 88), organic (Org.; n = 53), and mixed (Mix; n = 16) production.

	DACH			A
	D (%)	CH (%)	A (%)	Conv. (%)	Org. (%)	Mix (%)
Yes	97.5	88.7	89.9	93.2	83.0	93.8
No	2.5	11.3	10.1	6.8	17.0	6.2

Chi-squared test for different proportions between countries resp. production types showed no significant differences.

).

3.2. Impact of Drought on Potato Growers in the DACH Region

In Germany and Switzerland, 92% and 85%, respectively, of all potato growers surveyed had been affected by drought in the last ten years. In Austria, a total of 94% of potato growers stated that they were affected by drought, with organic potato growers feeling the effects of drought more than conventional potato growers (

Table 2. Which effects(s) related to climatic changes do you feel has (have) increasingly impacted your potato production in the last 10 years? Multiple answers allowed. Responses from German (D; n = 77), Swiss (CH; n = 47), and Austrian (A; n = 143) potato growers. Responses from Austrian potato growers are divided into conventional (Conv.; n = 82), organic (Org.; n = 44), and mixed (Mix; n = 15) production.

	DACH				A
	D (%)	CH (%)	A (%)	p	Conv. (%)	Org. (%)	Mix (%)	p
Drought	92.2	85.1	94.4		93.9	97.7	93.3
Heat	97.4	97.9	83.9		90.2	77.3	66.7
Pests and pathogens induced by climatic conditions	59.7	38.3	65.0	*	64.6	68.2	60.0
Heavy precipitation	24.7	44.7	42.7	*	41.5	52.3	26.7	*
Late spring frosts	7.8	14.9	25.9	**	24.4	31.8	26.7	*
Flash floods	6.5	6.4	18.2	*	15.9	27.3	13.3	**
Soil erosion	11.7	6.4	18.2		15.9	20.5	6.7
Others	6.5	4.3	7.7		8.5	6.8	6.7
Early autumn frosts	1.3	0.0	2.1		2.4	2.3	0.0

Chi-squared test for different proportions between countries resp. production types: * p < 0.05 ** p < 0.01.

).

The reported medium annual precipitation varied statistically significantly between the countries. Swiss potato growers reported the highest average precipitation, followed by German and finally Austrian potato growers. More than 75% of the German participants experienced medium annual precipitation of 500 to 700 mm, which is deemed optimal for high potato yields [12]. Among the Swiss participants, almost half reported a medium annual precipitation level of 700 to 900 mm, and 30% specified an annual medium precipitation of over 900 mm. One-third (32.1%) of the Austrian participants grow potatoes in an area with a medium annual precipitation between 500 and 700 mm, and almost half (47.2%) reported less than 500 mm of annual precipitation. Conventional potato growers reported less annual precipitation than organic potato growers (55% vs. 40% with less than 500 mm;

Table 3. Medium annual precipitation. Responses from German (D; n = 79), Swiss (CH; n = 53), and Austrian (A; n = 159) potato growers. Responses from Austrian potato growers are divided into conventional (Conv.; n = 88), organic (Org.; n = 53), and mixed (Mix; n = 16) production.

	DACH **			A
	D (%)	CH (%)	A (%)	Conv. (%)	Org. (%)	Mix (%)
<300 mm	0.0	0.0	6.3	4.6	7.6	12.5
300–500 mm	8.9	9.4	40.9	50.0	32.1	18.8
500–700 mm	75.9	13.2	32.1	30.7	39.6	18.8
700–900 mm	15.2	45.3	10.1	9.1	9.4	18.7
>900 mm	0.0	30.2	3.8	4.5	1.9	6.2
Unsure	0.0	1.9	6.9	1.1	9.4	25.0

Chi-squared test for different proportions between countries resp. production types: ** p < 0.01.

).

Nearly half of the German participants (49.3%) had access to at least partial irrigation. Irrigation was most common in Switzerland, where more than 66% had access to at least partial irrigation. In comparison, 39% of the Austrian potato growers indicated having access to at least partial irrigation, with similar numbers for conventional potato growers and organic potato growers (

Table 4. Possibility of irrigation. Responses from German (D; n = 79), Swiss (CH; n = 53), and Austrian (A; n = 159) potato growers. Responses from Austrian potato growers are divided into conventional (Conv.; n = 88), organic (Org.; n = 53), and mixed (Mix; n = 16) production.

	DACH **			A
	D (%)	CH (%)	A (%)	Conv. (%)	Org. (%)	Mix (%)
Yes	27.8	50.9	22.6	21.6	28.3	12.5
No	50.6	34.0	61.0	58.0	62.3	68.7
Partially	21.5	15.1	16.4	20.4	9.4	18.8

Chi-squared test for different proportions between countries resp. production types: ** p < 0.01.

).

Soil water retention capacities were reported to be highest in Switzerland, followed by Germany and Austria. Conventional potato growers generally reported lower soil water retention capacities than the organic potato growers (Document S2).

3.3. Impact of Heat on Potato Production in the DACH Region

Our survey revealed that heat had a substantial impact on potato production in DACH countries. A total of 97% of the German and 98% of the Swiss potato growers felt the impact of heat in the past. In comparison, 84% of the Austrian potato growers indicated heat-related challenges. Here, conventional potato growers were particularly affected by heat (Table 2).

Around 82% of both German and Swiss respondents and 72% of Austrian survey participants reported a high probability of maximum temperatures exceeding 26 °C for more than 7 days during the growing period. A statistically significant difference was found between the responses given by conventional and organic Austrian potato growers. Around half of the German respondents (50.6%) indicated a high probability of experiencing seven consecutive days with temperatures exceeding 30 °C. In comparison, 38% of the Swiss and 44% of the Austrian participants indicated the same probability. Again, there was a statistically significant difference between the responses given by conventional and organic Austrian potato growers (

Table 5. Probability of maximum temperature >26 °C (a) and >30 °C (b) for more than 7 days during the growing period. Responses from German (D; n = 79), Swiss (CH; n = 53), and Austrian (A; n = 159) potato growers. Responses from Austrian potato growers are divided into conventional (Conv.; n = 88), organic (Org.; n = 53), and mixed (Mix; n = 16) production.

	(a)	DACH			A **			(b)	DACH			A **
		D (%)	CH (%)	A (%)	Conv. (%)	Org. (%)	Mix (%)		D (%)	CH (%)	A (%)	Conv. (%)	Org. (%)	Mix (%)
High		82.3	83.0	71.7	85.3	54.7	50.0		50.6	37.7	44.0	53.4	32.1	100.0
Medium		16.5	15.1	22.6	12.5	32.1	50.0		43.0	50.9	41.5	40.9	39.6	0.0
Low		0.0	0.0	3.8	1.1	9.4	0.0		5.1	9.4	12.6	3.4	26.4	0.0
Unsure		1.3	1.9	1.9	1.1	3.8	0.0		1.3	1.9	1.9	2.3	1.9	0.0

Chi-squared test for different proportions between countries resp. production types: ** p < 0.01.

).

3.4. Further Impacts on Potato Production in the DACH Region: Pests, Pathogens, and Other Climatic Factors

A total of 60% of German, 38% of Swiss, and 65% of Austrian potato growers identified pests and pathogens induced by climatic conditions as important factors that negatively affected potato production in the last ten years. Among Austrian potato growers, 65% of conventional and 68% of organic potato growers indicated that pests and pathogens induced by climatic conditions had affected their potato production. Heavy precipitation was another important stress factor, mainly affecting Austrian and Swiss potato growers, as indicated by almost half of the respondents from Switzerland and Austria and only about a quarter of the respondents from Germany. Austrian potato growers faced additional challenges related to late spring frost (26%), flash floods (18%), and soil erosion (18%), which were more prevalent compared to replies given by German (late spring frost 8%, flash floods 6%, soil erosion 12%) and Swiss (late spring frost 15%, flash floods 6%, soil erosion 6%) potato growers. Among the Austrian potato growers, more organic than conventional potato growers reported issues with heavy precipitation, late spring frost, flash floods, and soil erosion (Table 2).

3.5. Adaptation Strategies for Mitigating Climate Change Effects on Potato Production

Our study examined the preferred adaptation strategies of potato growers in Germany, Switzerland, and Austria to mitigate the impacts of climate change. The most preferred adaptation strategy among potato growers in all three countries was to plant an adapted variety. It was favoured by around 70% of all potato growers in all three countries surveyed (

Table 6. Which adaptation strategies to climate changes are you willing to implement? Multiple answers allowed. Responses from German (D; n = 79), Swiss (CH; n = 53), and Austrian (A; n = 159) potato growers. Responses from Austrian potato growers are divided into conventional (Conv.; n = 88), organic (Org.; n = 53), and mixed (Mix; n = 16) production.

	DACH				A
	D (%)	CH (%)	A (%)	p	Conv. (%)	Org. (%)	Mix (%)	p
Planting an adapted variety	72.7	69.8	70.4		76.1	62.3	62.5
Change of planting and harvesting date	46.8	45.3	61.0		61.4	62.3	62.5
Tillage	59.5	43.4	52.2		59.1	49.1	31.2	*
Change in crop rotation	44.3	28.3	39.6		38.6	45.3	31.2
Irrigation	58.2	54.7	29.6	**	30.7	28.3	25.0
Planting an adapted genetically modified or genome edited variety	34.2	28.3	15.7	*	23.9	7.5	0.0	**
Others	0.0	1.9	3.1		3.4	1.9	6.2

Chi-squared test for different proportions between countries resp. production types: * p < 0.05 ** p < 0.01.

).

There were statistically significant variations in the belief that an adapted variety can mitigate the effects of climate change. Around 80% of the German and Swiss potato growers agreed that the impact of climatic change could be reduced by choosing an adapted variety. In comparison, 62% of Austrian potato growers agreed with this question. Around one-third of the Austrian potato growers—both conventional and organic—were not sure, and about 8% disagreed (Figure 1).

Other adaptation strategies include irrigation, changing of planting and harvesting dates, tillage, changing crop rotation, and planting a genetically modified or genome-edited variety (Table 6). Irrigation was a potentially implementable adaptation strategy for more than half of the German and Swiss potato growers. In Switzerland, irrigation was the second most frequently mentioned option. In comparison, less than a third (29.6%) of the Austrian potato growers indicated irrigation as an adaptation strategy. Changing planting and harvesting dates was preferred by less than half of the German and Swiss potato growers. In Austria, it was the second most frequently mentioned adaptation strategy. Around 61% of survey respondents were willing to implement it, with little difference between conventional and organic potato growers. In Germany, tillage was the second most mentioned adaptation strategy, mentioned by 60% of the participants. In comparison, 43% of the Swiss potato growers and 52% of the Austrian potato growers preferred tillage. More conventional than organic potato growers opted for tillage as an adaptation strategy. Change in crop rotation was chosen by 44% of the German, 28% of the Swiss, and 40% of the Austrian potato growers. Among the latter, more organic than conventional potato growers opted for a change in crop rotation. Planting an adapted genetically modified or genome-edited variety was mentioned by 34.2% of the German and 28.3% of the Swiss potato growers. Among Austrian potato growers, 16% chose this option, with a notable difference between conventional and organic production. In our survey, 24% of the conventional but only 8% of the organic potato growers considered this adaptation strategy.

4. Discussion

Surveys are a useful tool to provide a general overview of the issues at hand and offer a snapshot of the current sentiments among the respondents. However, depending on the survey design, the participants’ answers may be based on subjective experiences and could be temporarily or permanently influenced by external factors, e.g., media coverage of current drought events, ongoing heat waves, or personal interest in the topic [24,25]. The potential influence of the mentioned factors on the participants’ responses in our survey cannot be disregarded. Both the voluntary nature of the survey and potential bias in the replies must be considered when interpreting the results.

4.1. Climate-Change-Related Impacts Were Perceived by 88% of Potato Growers

In our study, 88% of the surveyed potato growers in the DACH region indicated that changing climatic conditions had affected their potato production in the past. More than 97% of German potato growers reported an impact of climatic changes on their production (Table 1). This percentage surpasses results of similar studies conducted on other crops, such as cereals in Germany [26,27], and apple and grape vine in Italy [28]. Whereas changing climatic conditions may facilitate future potato production in certain parts of northwestern Europe [29], it may pose severe challenges for potato production in other European regions. For instance, the last decade brought years of extreme weather conditions in each of the three countries in the DACH region, concomitant with a drastically reduced potato production [3,30,31].

4.2. Drought Is the Most Common Negative Influence on Potato Production in the DACH Region

More than 85% of all potato growers of the DACH region identified drought as an issue affecting their potato production. Due to its shallow root system, the potato crop is highly susceptible to water deficits, which can result in reduced growth and yield [14,15,32,33,34]. According to the FAO, the optimal rainfall range for achieving high potato yields ranges between 500 and 700 mm, and it is essential for the soil to maintain a relatively high moisture content throughout the growing season [12]. In addition to precipitation, soil water retention capacity plus the availability of irrigation play crucial roles for sufficient soil moisture levels.

Almost all surveyed German potato growers noticed the impact of drought on potato production in the past, despite over 90% of them receiving sufficient annual precipitation (i.e., more than 500 mm; Table 3). However, almost 40% of German potato growers reported having low or low–medium soil water retention capacities (Document S2), potentially impeding the crop’s ability to benefit from the rainfall. The potential for irrigation varies greatly across German regions, with the highest potential found in Lower Saxony [35], which is also the largest producer of potatoes in Germany [3].

Swiss potato growers had comparatively better conditions for potato cultivation, i.e., higher annual precipitation, more irrigation possibilities, and favourable soil water retention capacities. Nevertheless, despite Switzerland’s abundant water resources [36], 85% of the Swiss potato growers reported that their potato production had been impacted by drought in the past (Table 2). This percentage, although lower than in Germany and Austria, was still very high. More than 75% of the Swiss potato growers received more than 700 mm of annual precipitation, and 66% had access to irrigation (Table 3 and Table 4). Despite this, many respondents reported that drought had affected their potato production in the past. This may be due to unusually low annual precipitation or an unfavourable distribution of precipitation. The recent decrease in summer precipitation, coupled with rising summer temperatures and longer sunshine duration, has led to higher water evaporation rates and drought periods [37,38]. For instance, in the exceptionally warm and dry year 2018, many potato growers in the DACH region experienced a considerable decline in potato yields [3,37,39].

Almost all surveyed Austrian potato growers were affected by drought, which is consistent with the reported low annual precipitation, low soil water retention capacity, and limited possibility for irrigation. Increased transpiration due to heat should also be considered. Nearly half of the Austrian participants reported annual precipitation levels below 500 mm (Table 3). Based on climate scenarios, a further decrease in summer precipitation in Austria is expected, particularly in the eastern potato production areas [40]. This places their annual precipitation considerably lower than that reported by their counterparts in Germany and Switzerland, and falling below the optimal range [12]. Potatoes are mainly cultivated in the northeastern part of Lower Austria, specifically in the Weinviertel region (Figure S1). This region has experienced an increase in dry periods and is expected to remain highly prone to drought in the future [8,41]. The severe consequences of drought on Austrian potato production were particularly evident in 2015 when about a third less potatoes were harvested per hectare due to extremely hot and dry growing conditions [1,31,42,43]. The risk of drought in Austria is exacerbated by the limited water retention capacity of the soils and the limited irrigation options (Table 4, Document S2). The survey of European potato growers revealed that those from Austria had the least opportunity to irrigate [22]. In line with this, it is estimated that around 20–25% of the potato cultivation area in Austria can be irrigated (Interessengemeinschaft Erdäpfelbau (IGE), personal communication), compared to around 80% in some regions of Lower Saxony (E. Fricke, Landwirtschaftskammer Niedersachsen, personal communication).

4.3. Heat Waves Increasingly Impact Potato Production

More than 83% of the surveyed potato growers in the DACH region reported experiencing the effects of heat in the past. Optimal potato yield is typically achieved with average daily temperatures ranging between 18 and 20 °C [12]. However, when temperatures exceed 35 °C, heat stress conditions can severely diminish potato growth, yield, and quality [13,14,15,16]. Tuber induction is negatively affected by high night temperatures of around 21 °C, leading to further yield losses due to the delayed development of tubers [44]. Moreover, higher temperatures drive increased evaporative demand, which exacerbates drought conditions [41].

Our study revealed that periods of prolonged heat posed a severe challenge for more than 97% of all German and Swiss potato growers (Table 2), which is considerably higher than the 44% reported for German cereal growers in a similar survey [26]. Potatoes, however, may be more vulnerable to heat than cereals due to their later harvesting time, increasing the likelihood of experiencing a late summer heat wave. In 2022, there were reports of heat-damaged potatoes in North Rhine-Westphalia, which made the potatoes more prone to pests and unsuitable for storage [45]. In Switzerland, the extremely hot July in 2013 led to a drop in yield by one-third compared to previous years [5,46]. The frequency of heat days, defined as temperatures exceeding 30 °C, has increased in recent decades [38]. The minority of surveyed potato growers rated the probability of having more than seven heat days (>30 °C) in the growing season as low. The probability of such a heat wave was estimated to be lowest in Austria, followed by Switzerland and Germany (Table 5). Correspondingly, fewer potato growers from Austria stated that their potato production suffered from heat. Nevertheless, around 84% of Austrian potato growers felt the effects of heat (Table 2).

4.4. German and Austrian Potato Growers Suffer from Pests and Pathogens

In Germany and Austria, three out of five surveyed potato growers reported that they have been affected by pests and pathogens induced by changing climate conditions (Table 2). Many factors, including climate change, may influence the occurrence of pests and pathogens. In particular, the impact of climate change on plant pathogens is complex and difficult to predict [47,48]. It has been shown that increasing temperatures facilitate pathogen evolution, leading to higher productivity and more generations as well as expanded geographic ranges [13,49,50]. Besides this, drought may affect the occurrence of pests through metabolic changes that increase plant attractiveness and susceptibility [51], a higher risk of pathogen transmission [52], altered host–pathogen interactions [53], and the emergence of new pathogens [54,55]. On the other hand, changes in precipitation patterns may lead to increased occurrence of pests and pathogens. Some potato growers provided specific examples of pests and pathogens that affected their potato crops in the past decade (Document S3), including wireworm (Agriotes spp., Hemicrepidius spp., Selatosomus spp.), early blight (Alternaria spp.), late blight (Phytophtora infestans), and Stolbur (‘Candidatus Phytoplasma solani’). Serious damage has been recorded in hot and dry years in particular, e.g., wireworm in 2018 in Austria, resulting in tubers that were unsuitable for the fresh market and had to be diverted to the starch industry or biogas plants at discounted prices [56,57].

Similarly, in Austria’s Weinviertel region, Stolbur in 2017 and 2018 led to the development of unmarketable, spongy tubers [58,59]. Furthermore, the impact of early blight (Alternaria) that causes dry, brown, and brittle leaves and reduced storability of tubers is increased in dry and hot years [60]. In the context of increased presence of pests and pathogens, the ban on pesticides has challenged potato production, as mentioned by several potato growers from all three countries (Document S3). Indeed, the susceptibility of potatoes to insects, weeds, fungi, and viruses requires diligent management strategies, which may include the use of pesticides. Table 2 shows that fewer potato growers in Switzerland were affected by pest and pathogens. This can be attributed to various reasons, such as the absence of specific pests and pathogens in certain areas, different regulations governing their control, or regional climate variations. According to the survey results in Table 2, Table 3 and Table 4, Swiss potato growers experience higher annual precipitation, have more irrigation options, and are less affected by drought compared to those in Germany and Austria. This may reduce the risk of drought-induced pests and pathogens.

4.5. Heavy Precipitation Impacts Potato Production in Switzerland and Austria, as Well as Flash Floods and Soil Erosion in Austria

While all three countries highlighted the severity of drought and heat, there were notable differences in the impact of other factors such as flash flooding, soil erosion, and late spring frost. Heavy precipitation was identified as a considerable negative issue in potato production by more than 40% of Austrian and Swiss participants, compared to only 24% of German participants. This is consistent with reports of heavy precipitation events in Switzerland and Austria, which have increased in intensity over the past decade. However, there has only been a minimal increase in frequency reported for Germany [61,62,63,64]. Accordingly, about 18% of Austrian and less than 7% of German and Swiss potato growers indicated facing issues with flash floods (Table 2). Heavy precipitation and flash floods pose major challenges due to their impact on soil conditions. They may cause delays in planting and harvesting operations as fields become inaccessible or muddy. Excessive rainfall and flash floods can lead to waterlogged and saturated soil, which hampers root respiration and nutrient absorption, resulting in poor growth and development of potato plants [65]. Moreover, excessive water can contribute to soil erosion, which is a concern for potato growers due to the crop’s special seedbed structure and the late plant development. Soil erosion concerns were mentioned by 18% of the Austrian potato growers but less frequently by Swiss and German potato growers (Table 2). It is worth noting that erosion control is an important and frequently discussed topic in Austria, and there are also national funding opportunities available to support erosion control measures that may influence the perception of the potato growers [66].

4.6. Late Spring Frost Is a Problem in Austria

In Austria, more than a quarter of the participants reported that their potato production was affected by late spring frost, thus being considerably more than in Germany and Switzerland (Table 2). This could be attributed to the large market for early potatoes in Austria [8], which are planted earlier and thus are potentially more exposed to late spring frost. Late spring frost can severely damage the potato plants, as they are unable to frost-harden and can be killed by temperatures as low as −3 °C [67,68]. In Germany, potato growers with irrigation facilities may irrigate their potatoes when there is a risk of frost to protect them from freezing (Figure S2). However, limited irrigation possibilities in Austria mean that potato growers have fewer options for adapting to late frosts.

4.7. Potato Growers’ Desired Adaptation Strategies for Mitigating Climate Change Effects

Acknowledging climate change serves as a fundamental precondition for having adaptation intentions [69,70]. Our survey shows that most potato growers are aware of climate change and its impacts. Research indicates that without adaptation, potato yields may decline substantially [71], but implementing adaptation strategies could increase global potato yields by 9 to 20% [72]. However, potato growers’ willingness to implement adaptation measures varies, depending on factors such as awareness of effective methods, personal responsibility, and perceived adaptation costs [70].

Among surveyed potato growers in the DACH region, around 70% indicated that planting adapted varieties was their preferred adaptation strategy (Table 6). This finding is consistent with the results of an expert study [73] and supported by simulation studies [74]. According to projections, by the end of the century, 39% of global cropland may require new crop varieties to avoid yield losses caused by climate change [75]. Breeding companies are developing adapted varieties, and certain potato cultivars have already been found to exhibit higher drought tolerance than others, e.g., by increased root length or altered maturities [32,76,77].

However, potato growers in Austria are uncertain as to whether relying solely on an adapted variety is sufficient to cope with the challenges associated with a changing climate (Figure 1). It seems reasonable that breeding new varieties alone can only be one piece of the puzzle in the climate change adaptation system. It usually takes around ten years for a new variety to reach the market. Moreover, breeding varieties to mitigate future challenges from specific or combined abiotic stresses is a complex task, even with substantial knowledge of potato genetics [78].

More than half of the German and Swiss potato growers consider irrigation as a desirable adaptation strategy. Irrigation has been shown to be necessary for optimal potato growth in many regions of Germany, such as Lower Saxony, where predominantly light soils with limited water-holding capacity are common. Irrigation has the potential to increase potato yield up to 27% [79,80,81]. An increased demand for irrigation in future potato cultivation is projected to mitigate the effects of drought and maintain stable potato yields [36,82,83,84]. In 2015, about half of the potato area in Lower Saxony was irrigated [81], and it is estimated that this figure has increased up to 80% by 2023 (E. Fricke, Landwirtschaftskammer Niedersachsen, personal communication). In Austria, only one-third of the potato growers stated their willingness to implement irrigation, despite the challenging drought conditions they face. The reasons for this might be diverse and should be interpreted cautiously. Remarkably, of the Austrian potato growers who indicated that they did not have the possibility to irrigate, only 5% were willing to implement irrigation (Document S3). Barriers like administrative hurdles, legal requirements for water rights, and economic considerations may discourage Austrian potato growers from installing irrigation systems. The uncertainty regarding long-term climate risks, coupled with a predominant focus on short-term profitability and business survival, adds to these challenges [85]. The small acreage of many Austrian farms (Document S1) results in higher costs per hectare, making investment in irrigation less appealing. Moreover, limited water availability might be another constraint for Austrian potato growers. Groundwater is the primary source of irrigation in Austria. However, accessing groundwater is challenging in many regions of Lower Austria, which is the country’s main potato production area [86]. But also in irrigable areas, declining groundwater levels are leading to irrigation restrictions. According to projections, by 2050, around 80% or more of the naturally available water supply in eastern Austria will be depleted. Utilising surface water sources like the Danube River offers a potential solution to extend irrigable areas beyond groundwater-dependent regions [87]. Around 60% of the Austrian potato growers and approximately 45% of German and Swiss potato growers prefer adjusting the planting and harvesting dates as a potential adaption strategy (Table 6). Shifting to an earlier planting date in the growing season prolongs cultivation time and enables the utilisation of moist spring conditions while avoiding the arid and high-temperature conditions of late summer [72].

Among German potato growers, tillage was the second most desired adaptation strategy, mentioned by almost 60% of the German participants, as well as 52% of the Austrian and 43% of the Swiss potato growers (Table 6). Tillage serves various agronomic purposes, including weed and pest suppression, fertiliser incorporation, root proliferation, water infiltration, and soil warming. Change in crop rotation was seen as a viable adaptation strategy to climate change by more than 40% of the German potato growers, whereas it was mentioned less frequently by participants from Austria and Switzerland. Crop rotation is a widely adopted strategy that reduces reliance on specific nutrients, manages pests and weeds, and decreases the likelihood of developing resistant pests and weeds. Finally, only 16% of Austrian potato growers were willing to plant genetically modified or genome edited varieties. This is a lower percentage compared to Switzerland (28%) and Germany (34%). The higher number of organic potato growers responding to the survey coming from Austria (Document S1) may explain this, but it also likely reflects debates and perceptions of biotechnology in the different countries.

4.8. Differences of Organic and Conventional Potato Growers in Austria

More than 83% of organic and more than 93% of conventional potato growers in Austria reported that changes in climatic conditions affected their potato production (Table 1). Both organic and conventional potato growers faced similar drought-related challenges, such as annual precipitation, soil water retention capacities, and irrigation possibilities (Table 2, Table 3 and Table 4). The factor heat was perceived differently between organic and conventional potato growers. About 77% of organic potato growers noted the impact of heat on their potato production, compared to 90% of conventional potato growers (Table 2). Correspondingly, more conventional than organic potato growers reported facing heat waves (>30 °C) during the growing season (Table 5). In addition, more organic potato growers reported heavy precipitation, flash floods, soil erosion, and late spring frost impacting their potato production (Table 2). This disparity might be influenced by the geographical location of the surveyed farms. It is plausible that the organic potato growers surveyed primarily operated in cooler regions of Austria, such as the northern Waldviertel, while the conventional potato growers were more prevalent in the hotter and drier Weinviertel region. This is also true for the table potato producers (Figure S1). Although organic potato growers generally have fewer options for pest and pathogen control, only slightly more organic than conventional potato growers have experienced the impact of climate-induced pests and pathogens on their potato production (Table 2). This may reflect that pests are more likely to occur in warmer areas and thus affect potentially more conventional than organic farmers. Furthermore, this observed convergence might be caused by the recent trend to reduce the use of pesticides in conventional agriculture.

Similar to a study conducted in Germany [88], the majority of potato growers in Austria, both organic and conventional, indicated that selecting an adapted potato variety could reduce the impact of climatic change on potato production. However, approximately one-third of the growers were uncertain about the effectiveness of this strategy (Figure 1). The results of the survey showed that a greater proportion of conventional potato growers were willing to plant an adapted variety as an adaptation strategy to reduce the impact of climatic changes. In contrast, for organic potato growers, both planting an adapted variety and changing planting and harvesting dates were equally relevant, with over 60% expressing interest in these strategies (Table 6). Interestingly, the study revealed that organic potato growers were less inclined to implement tillage as an adaptation strategy compared to conventional potato growers (Table 6). It is possible that organic potato growers do not perceive tillage as an effective adaptation strategy to climate change or prefer reduced tillage practices to minimise environmental impact. In both groups, approximately 30% of the potato growers expressed their willingness to implement irrigation as an adaptation strategy to mitigate the impact of climatic changes on potato production. Nearly a quarter of conventional potato growers are open to planting adapted genetically modified or genome-edited varieties, while only 8% of organic potato growers are willing to do so (Table 6). This increased acceptance among conventional potato growers reflects the general European trend and may also be influenced by the ongoing discussion on the use of genome editing in organic farming [89,90].

5. Conclusions

Our study provides several important insights into the effects of climate change on potato production in the DACH region (Germany, Austria, Switzerland). We found a strong consensus among potato growers that the changing climatic conditions adversely impacted their potato production. This calls for immediate action to develop strategies that can help growers adapt to these challenges and maintain potato yields despite climate change. Most potato growers in the DACH region have reported negative impacts of drought on potato yields, highlighting the vulnerability of potato production to water deficits and drought. This perception was also reported when potatoes were produced on sites with the optimal range of annual precipitation. Another major challenge for potato growers in the DACH region, especially in Germany and Switzerland, is heat stress, resulting in reduced yields, crop damage, and reduced storage suitability. Many potato growers have reported a high frequency of heat waves, with temperatures reaching over 30 °C for seven days. The likelihood and magnitude of hot summers will continue to increase [38]. Climate-change-induced pests and pathogens are a major problem for potato growers in the DACH region. The pressure from pests and pathogens is expected to increase due to climatic changes. Our study shows that several strategies should be followed to ensure sustainable potato production in the DACH region. Effective water management strategies and irrigation systems are crucial to mitigate the effects of drought. It is essential to develop holistic strategies to counteract heat and adapt to changing temperature patterns. The impact of pests and pathogens can be mitigated by applying concepts such as integrated pest management and developing resistant varieties. Regional differences that are likely due to specific regional climate patterns included reports on heavy precipitation events, including flash floods, soil erosion, and late spring frost. Among potential adaptation strategies, growing adapted varieties was favoured in all three countries. However, different levels of acceptance were observed for alternative strategies such as tillage, irrigation, adjusting planting and harvesting dates, crop rotation, and the use of genetically modified or genome-edited varieties. These results highlight the need to understand country-specific challenges to develop effective climate change mitigation strategies for potato production.