Marginal crops cultivation for food production

Climate change significantly impacts agriculture in Central Europe, affecting crop yields, soil health, water availability, and pest and disease management. The region is experiencing rising temperatures, changes in precipitation patterns, and more frequent extreme weather events, such as droughts and floods. Table 1 shows the changes in temperatures, precipitation, and vegetation period in Central Europe over the past century, based on data from several scientific studies:

Table 1. Changes in climate over the past century in Central Europe

The main problems caused by climate change in plant production are mainly caused by changes in the distribution of precipitation and increasing temperatures. This then affects other factors, such as the risk of soil erosion, leaching of nutrients, changes in weed communities, and the occurrence of previously rare diseases or pests. An overview is given in Table 2.

Table 2. Main problems caused by climatic change in crop production

Strategies in Crop Production to Reduce the Negative Impact of Climate Change

Climate-resilient agriculture involves implementing various strategies that aim to help farmers adapt to the changing climate and improve their crop production despite the challenges posed by climate change. These strategies can be employed in climate-resilient agriculture to improve crop production and help farmers adapt to the changing climate.

• Diversification of crops and use of drought-tolerant crops: Farmers can diversify their crop production by growing crops tolerating different climatic conditions. This will ensure that other crops can still thrive if one crop fails due to unfavorable weather conditions.

• Growing of crops or varieties mixtures: Crop mixtures can also adapt to changing climate conditions by selecting crop combinations that are better suited to the local climate or by using mixtures that are more tolerant to specific stresses such as drought, heat, or flooding.

• Conservation agriculture: This involves practices such as reduced tillage, cover cropping, and intercropping, which help to conserve soil moisture, reduce soil erosion, and increase soil fertility.

• Efficient irrigation: Efficient irrigation systems such as drip and sprinkler irrigation can help farmers conserve water and reduce the water needed for crop production.

• Soil management: Proper soil management practices such as soil testing, fertilization, and organic matter can help improve soil quality, which can improve crop yields.

• Crop rotation: Farmers can rotate crops to help manage pests and diseases and improve soil health.

• Agroforestry: This involves integrating trees into farming systems, which can provide shade, reduce soil erosion, and improve soil fertility.

• Use of weather information: Farmers can use weather information to make informed decisions about planting and harvesting times and other farm management practices.

• Use of improved seed varieties: Farmers can use improved seed varieties that are resistant to pests and diseases and are adapted to local climatic conditions.

In the next part of the text, attention is paid diversification of crops, and use of drought-tolerant crops, and the growing of crops or varieties mixtures. The other mentioned methods are part of other chapters.

Diversification of Crops and Use of Drought-Tolerant Crops: The Importance of Cereals for Agriculture in Conditions of a Changing Climate

Climate change poses significant challenges to cereal crop production, including increased temperatures, changing rainfall patterns, and more frequent extreme weather events. In general, cereals are the most adaptable group of crops to climate change. However, some cereal crops are better adapted to these changing conditions than others. Here are some examples of cereals that are good in the conditions of changing climate:

Einkorn wheat (Triticum monococcum L.)

Studies have shown that einkorn wheat has more drought tolerance and plasticity than other modern wheat varieties. This is caused mainly because the root system of plants is deep, and that allows them to access water from deeper soil layers, making it less dependent on rainfall. Additionally, einkorn wheat has a thick wax layer on its leaves and stems, which helps to reduce water loss through transpiration. According to many studies, einkorn wheat has been found to have a higher yield under drought conditions than other wheat species [32].

Emmer wheat (Triticum diccocum (Schrank.) Schuebl.)

Triticum dicoccum, or emmer wheat, is an ancient species cultivated for thousands of years. Due to some plant characteristics, it is known for its ability to tolerate drought conditions and plasticity. The root system of plants has an extensive root system that can access water from deeper soil layers, making it less dependent on rainfall. Studies have shown that this deep root system allows emmer wheat to maintain growth and yield under drought conditions [36]. Emmer wheat has a thick wax layer on its leaves and stems, which reduces water loss through transpiration. This wax layer also helps to protect the plant from high temperatures and other environmental stresses [34]. Emmer wheat can also adjust its osmotic potential by accumulating osmoprotectants, such as proline and soluble sugars, in response to drought stress. This helps to maintain cellular water balance and prevents dehydration [18]. Plants also can regulate stomatal closure in response to water stress, which helps to reduce water loss through transpiration. Due to this stomatal regulation, emmer wheat can maintain high photosynthetic rates under drought conditions [36]. Emmer wheat is a promising crop for regions with limited water resources and may be a valuable tool in addressing water scarcity and climate change issues.

Spelt (Triticum spelta L.)

Triticum spelta, also known as spelt wheat, is another ancient wheat species historically cultivated. It is also known for its ability to tolerate drought conditions and plasticity. Spelt wheat has an extensive root system that can penetrate the soil deeply and absorb water from different soil layers. Studies have shown that spelt wheat has a greater root length density than other wheat species, which helps it to access water from deeper soil layers and maintain growth under drought conditions [31]. Like emmer wheat, spelt wheat has a high wax content on its leaves, which reduces water loss through transpiration. Studies have shown that this wax layer helps spelt wheat to maintain its water status and prevents dehydration under drought conditions [7]. Another aspect is an osmotic adjustment. In response to drought stress, plants can accumulate osmoprotectants, such as proline and soluble sugars. This helps to maintain cellular water balance and prevent dehydration [7]. Practical is also the ability to regulate stomatal closure in response to water stress, which helps to reduce water loss through transpiration [31].

Millet (Panicum milliaceum L.)

Millets are cereal crops highly adapted to hot and dry conditions, making them an excellent choice for areas with limited water availability. Millets require significantly less water than cereal crops such as maize or wheat. Millets have a fibrous root system that can penetrate the soil deeply and access water from different soil layers [30]. Helpful is also the ability rolling of leaves as a response to drought stress. This mechanism helps to maintain water status and prevent dehydration under drought conditions [2]. Millets can also adjust their osmotic potential by accumulating osmoprotectants, such as proline and soluble sugars [19]. Effectively, it also can regulate stomatal closure in response to water stress, which helps to reduce water loss through transpiration [3].

Sorghum (Sorghum bicolor L.)

Sorghum is a warm-season cereal crop widely cultivated for its grain and forage. Sorghum is traditionally grown in arid areas of the African continent. Sorghum's extensive root system can access water from deeper soil layers, making it less dependent on rainfall [19]. Plants can roll their leaves in response to water stress, which helps to reduce water loss through transpiration [2]. In response to drought stress, sorghum can adjust its osmotic potential by accumulating osmoprotectants, such as proline and soluble sugars [29]. Sorghum can also regulate stomatal closure in response to water stress, which helps to reduce water loss through transpiration. Due to this stomatal regulation, sorghum can maintain photosynthetic rates under drought conditions [22]. Sorghum is a promising crop for regions with limited water resources but requires relatively high temperatures for vegetation. In European conditions, ripening is inevitable only in the warmest areas. It is also beginning to establish itself as a green fodder crop, where the problems of certainty of ripening are eliminated.

Buckwheat (Fagopyrum exculentum Moench.)

Buckwheat is a pseudo-cereal crop adapted to cooler temperatures and can tolerate various soil types. It is also relatively resistant to pests and diseases, making it a low-input crop. Although it is generally considered a crop that requires moist soils, there is evidence that some varieties can be relatively drought-tolerant. Buckwheat has a fibrous root system that can penetrate the soil deeply and access water from different soil layers [26]. Plants can roll their leaves in response to water stress, which helps to reduce water loss through transpiration [37]. The ability to adjust osmotic potential helps to maintain cellular water balance and prevent dehydration [39]. Buckwheat has been found to have relatively high water-use efficiency, meaning it can produce more biomass per unit of water used than other crops [10]. Overall, buckwheat has some potential for drought tolerance, but more research is needed to identify the specific varieties and conditions under which it performs best under drought conditions.

Quinoa (Chenopodium quinoa Willd.)

Quinoa is a hardy cereal crop that can tolerate extreme temperatures, from freezing to high heat. It also requires less water than other cereal crops and is highly resistant to pests and diseases. Quinoa requires much less water than other crops, making it well-suited to areas with low rainfall and limited irrigation. It can survive with as little as 250-300 mm of rainfall per year, while many other crops require at least 500-600 mm [4]. Quinoa is traditionally grown in the Andean region of South America, characterized by arid conditions [15]. It has been cultivated for centuries in areas where other crops cannot grow due to a lack of water. Quinoa is known for its ability to efficiently use water, as it has a small leaf area and a deep root system that allows it to access water from lower soil layers [38]. Quinoa has a unique strategy for drought escape, where it rapidly matures and produces seeds before the onset of drought conditions [4]. Overall, quinoa's drought tolerance and adaptability to arid and semi-arid regions make it a promising crop for sustainable agriculture in the face of climate change and increasing water scarcity.

Barley (Hordeum vulgare L.)

Barley is an exciting crop because it is traditionally grown in the Central European region. It is a crop well-suited to cooler temperatures and can tolerate various soil types. It is also relatively drought-tolerant and requires less water than other cereal crops such as maize or wheat. Drought tolerance in barley can be achieved through traits such as deep root systems, reduced leaf area, and increased water use efficiency [9]. Barley can also exhibit a range of adaptive responses to climate change, including changes in the timing of developmental stages, shifts in distribution and phenology, and alterations in growth and physiological processes [27]. Barley has a relatively deep root system, which allows it to access soil moisture from deeper layers [23]. Barley can also increase its drought tolerance by regulating gene expression, such as the expression of the DREB1 transcription factor gene [13]. Mentioned characteristics of barley cause the plants to tolerate a range of climate conditions, including high temperatures and drought stress [6].

Mentioned cereal species are better adapted to the changing climate conditions and can be grown with less water and fewer inputs, making them ideal for areas with limited resources. These crops are also suitable to be grown in organic farming. Farmers can enhance their food security and improve their resilience to climate change by promoting cultivating these climate-resilient cereal crops.

In addition to the mentioned properties, which predetermine the mentioned cereals for cultivation in a changing climate, it is also possible to use their second advantage, which can support their cultivation. These are types of cereals that have proven nutritional benefits. Apart from hulled wheat (eeinkorn emmer, spelt), these are gluten-free foods.

The main advantage of hulled wheat species is the high protein content in the grain, which, even under organic farming conditions, reaches 15% or more. From a nutritional point of view, the high content of protoplasmic protein fractions is positive. Eincorn and emmer are unsuitable for making classic yeasted products; therefore, they are used in the food industry to prepare other products, such as pasta. More information is provided in Table 3. The most common barley product is beer. However, barley is an underappreciated raw material from the point of view of food processing because a wide range of products can be prepared from it. Naked forms of barley are most suitable for food processing.

Table 3. Specific production quality of hulled wheat species and barley

The crops listed in Table 4 have the advantage that they are all usable for gluten-free products. These are traditional crops from which many traditional food products are produced. However, many of them are unknown to consumers in Europe, so it is important to take this fact into account when marketing them. The main disadvantage of quinoa is its high price.

Table 4. Specific production quality of hulled wheat species

Growing of Crops or Varieties Mixtures: Possibilities of Using Mixed Cultures to Increase Resistance to Climate Change

Crop mixtures, or intercropping, involve planting two or more crops together in the same field. This farming practice can help mitigate the negative impacts of climate change on crop production by increasing biodiversity and reducing the risk of crop failure. Here are some ways crop mixtures can be used as a tool against the negative impacts of climate change:

• Diversifying crop production: Intercropping allows for the cultivation of different crops in the same field, which can increase the resilience of the cropping system to climate change impacts. For example, a study conducted in China found that intercropping maize with soybean increased yield stability and reduced the risk of crop failure compared to monoculture.

• Enhancing soil health: Crop mixtures can improve soil health by increasing the diversity of soil microorganisms and enhancing nutrient cycling. This can improve soil fertility and increase crop productivity, which can help farmers adapt to changing climatic conditions. For example, a study conducted in Brazil found that intercropping maize and beans improved soil fertility and increased crop yield compared to monoculture.

• Managing pests and diseases: Intercropping can also help manage pests and diseases by disrupting pests' habitats and reducing the spread of diseases. This can reduce the need for chemical pesticides and fungicides, which can have negative environmental impacts. For example, a study conducted in Canada found that intercropping wheat and peas reduced the incidence of common root rot compared to monoculture.

Here are some examples of crop mixtures used in Central Europe to mitigate the negative impacts of climate change on crop production. Winter wheat and field beans were tested in Germany. Intercropping winter wheat and field beans has been found to improve soil fertility and increase crop yield compared to monoculture. The mixture also reduced the risk of nitrogen leaching and improved nutrient uptake efficiency [20]. Rye and legume intercropping were tested in Poland. Intercropping of rye with legumes such as vetch, peas, or clover has improved soil structure and fertility, reduced erosion, and increased yield stability [35]. In Hungary, experiments with intercropping corn and soybeans have been found to increase yield stability, improve soil fertility, and reduce the risk of insect and disease infestations [1]. Austrian scientists conducted research in intercropping winter wheat with clover has improved drought tolerance, as clover helps maintain soil moisture and reduce evapotranspiration. This mixture improves soil structure and fertility [12]. In Germany, Barley and legume (pea or faba bean) intercropping was tested. Noted was increased yield stability and drought tolerance compared to monoculture [16]. Maize and beans intercropping were tested in Switzerland and has been found to increase drought tolerance and improve soil health by enhancing nutrient cycling and soil organic matter [33]. More examples, including the stated effect and a link to the author, are given in table 5.

Table 5. Examples of benefits of intercropping

Varietal mixtures, involve growing a greater diversity of wheat varieties in a mixture can provide several benefits in the face of climate change and help maintain yield stability:

• Climate resilience: With a changing climate, extreme weather events such as droughts, heat waves, and heavy rainfall are becoming more frequent [17]. Growing a mixture of wheat varieties with different traits can help increase resilience to such events. For example, some varieties may have deeper root systems that can access water from deeper in the soil, while others may have traits that enable them to tolerate heat or drought better.

• Pest and disease resistance: Growing a mixture of wheat varieties can reduce the risk of pest and disease outbreaks. When multiple varieties are grown together, pests and diseases are less likely to spread and can be more easily controlled.

• Yield stability: Growing a mixture of wheat varieties can help ensure more stable yields over time. Because different varieties have different growth patterns and responses to environmental conditions, some varieties may perform better in one year while others may perform better in another. By growing a mixture of varieties, farmers can better ensure that they have a good crop in any given year.

• Nutrient efficiency: Some wheat varieties are better adapted to specific soil conditions or nutrient levels. Growing a mixture of varieties can help ensure that all soil nutrients are used effectively, leading to more efficient nutrient use and potentially higher yields.

• Enhanced biodiversity: Growing a mixture of wheat varieties can contribute to increased biodiversity on the farm. By diversifying the crop, farmers can provide a habitat for a broader range of plant and animal species, which can help maintain a healthy and balanced ecosystem.

• Reduced environmental impact: Growing a mixture of wheat varieties can reduce the environmental impact of farming by reducing the need for synthetic inputs such as fertilizers and pesticides. The diversity of the crop can help control pests and diseases naturally, reducing the need for chemical interventions.

• Improved soil health: Growing a mixture of wheat varieties can improve soil health by promoting the growth of beneficial soil microorganisms. Different varieties may have different root structures and secrete different compounds that can help promote soil microbial diversity and activity.

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