Field of Action Agriculture

Field with farming tailer - a single spike in the foregroundClick to enlarge
Changes in precipitation pattern due to climate change affect agriculture.
Source: suze / photocase.com

Impacts of Climate Change

Table of Contents

 

Precipitation

In the context of climate change, the amount of rainfall and its distribution is changing in Germany. This has a direct effect on the temporal and regional availability of water. Altered precipitation leads to fluctuations in soil water and groundwater levels. Thus, the soil quality and productivity of agricultural land are affected. If the temperatures rise at the same time, the consequences for the agricultural production will be even more severe.

Decreasing rainfall in the summer months is expected as a result of climate change affecting south-west Germany and parts of the eastern federal states in particular. In these regions which are already relatively warm or dry, the changing climate is becoming increasingly problematic for agricultural activities. The scenarios set up in climate research projects assume that there will be a decrease in summer precipitation by up to 30 per cent by 2080. Heat and drought damages may reduce both the yield and the quality of the harvest.

However, also excessive amounts of rain due to climate change may have consequences for the agricultural production, as too much moisture affects plant growth just as negatively as droughts.

 

Temperature

The number of hot days will increase significantly as a result of climate change. These temperature changes will have diverse effects on agriculture: they have consequences for vegetation and growth periods of crops, affect plant and animal health and thus the productivity of the entire agricultural economy.

As a result of rising temperatures, it is expected that plant diseases and pests so far only found in warmer regions will spread. This has effects on fruit production, for example. Thus, the fungal disease apple scab has already led to high quality and yield losses, especially in south-west Germany. Infected plants are less resistant to water and temperature stress and thus more vulnerable to the impacts of climate change.

Higher average temperatures and milder winters lead to a shift of cultivation areas to the north and to changes in vegetation and growing seasons of plants.

Especially fewer frost days in spring can lead to an earlier start of growth. The cultivation of new varieties, especially of heat-loving species such as maize or millet, becomes possible. Certain production areas in northern Germany and in mid-mountain areas that are comparatively cool and humid today can benefit from these developments. In those regions it is expected that a moderate temperature rise and a sufficient water supply will entail an increased harvesting potential for many crops.However, some plant species may also be disturbed in their growth by climate change. Some cereal crops like wheat, for example, are extremely sensitive to heat during flowering. Temperatures above 30 degrees Celsius during this period can lead to a severe crop loss.

In Germany, animal health and the productivity of livestock breeding are increasingly threatened by so-called vector-borne diseases. These are diseases that are transmitted by pests or parasites. With rising temperatures and fewer frost periods, these can spread to new habitats. Thus, also the diseases they transmit spread. In recent years, certain mosquito species, for example, have transmitted the bluetongue and the Schmallenberg virus.

Due to climate change, also the heat stress for the livestock increases. As a consequence of their high metabolic activity and the resulting heat production, especially dairy cows are sensitive to temperature changes. Increasing heat can therefore lead to yield losses in the dairy industry. A reduced quality of feedingstuffs due to climate change in the agricultural economy even increases this trend.

 

Extreme weather events

Experts assume that it is probable or even highly probable that extreme weather events such as dry and drought periods, torrential rain, hail and thunderstorms will increase in Germany over the next three decades. Only an increase of storms is less certain. Extreme heat, frost or prolonged drought periods and excessive moisture result in significant yield losses. The effects are particularly strong if temperature or water stress occurs during particularly sensitive phases of plant growth, such as during the leaf formation.

Heavy rain also entails increased runoffs and therefore  often  leads to soil erosion or damages the agricultural infrastructure through floods. Storm can carry away fertile topsoil, too.

In general, the increasing variability (different weather conditions from one year to the next) and increased extreme weather events can lead to greater harvesting fluctuations and impede adaptation.

 

CO2 fertilisation

More carbon dioxide (CO2) can lead to an increased plant growth. However, the effect is not the same with regard to all plants. Particularly C3 and C4 plants are of importance for agriculture. They differ in terms of their leaf anatomy and the metabolic process during photosynthesis. C4 plants are better at absorbing carbon.Most crops grown in Germany belong to the category of C3 plants. These include wheat, sugar beet and potato. As far as these plants are concerned, normal temperature and light conditions mean that the photosynthesis rate increases with an increased concentration of CO2 in the air. However, in case of heat or drought, this effect diminishes.

In contrast, C4 plants – such as maize, sugarcane and millet which mostly have a tropical or subtropical origin – have the ability to use lower CO2 concentrations in the air. Under heat and drought stress, they are superior to C3 plants. A change in the CO2concentration in the air hardly affects their growth.

Thus, CO2 changes affect the growth of some plant species positively. Furthermore, both C3 and C4 plants benefit from an effect that improves their water use efficiency in case of high atmospheric CO2 concentration. This could be crucial if the water availability decreases. However, overall it is assumed that neither of both effects is capable of compensating the limiting effects of climate change on agriculture.

If you are interested in obtaining information about possible adaptation measures in the field of action agriculture, please click here.

 

Sources

Adaptation to Climate Change

Technical measures

Especially technical measures that improve weather forecasts and warning systems are relevant for adaptation to climate change in the agricultural sector. They enable farmers to prepare for weather changes and extreme weather events and to take protective measures.

Plants and animals can also be protected directly through technical measures, especially against extreme weather events. Putting up nets above fruit trees or vines protect them from damage due to hail. An additional hail insurance is recommended for particularly valuable crops. Watering plants during heat periods can meet the increasing demand for water. Customised drip irrigation can also help to save water. In order to protect livestock from heat, stables can be equipped with sufficient thermal insulation and light roof surfaces.

Ecosystem measures

Ecosystem measures are of particular importance for climate change adaptation in the agricultural sector. Adjusting sowing dates can be a suitable means to react to the shift of seasons: summer grain should be sown earlier in order to benefit from the moist soil in spring. Winter grain, however, should be sown later in the year, to ensure that the cold period, which is of crucial importance for the crop, does not occur too late. During transition phases, the use of deep-rooted crops, such as grasses, can reduce the risk of drought damage in the summer and protect the soil against erosion.

Also the selection of the seeds should be adapted to climate changes. Especially those species that are less susceptible to drought stress and generally prove to be robust against pests and climate fluctuations are likely to respond to climate change effectively. In addition, the climate changes also allow the introduction of fruit species that have so far rarely been cultivated in Germany. Certain varieties of maize, millet and other heat-loving species that have high water use efficiency are particularly suitable.

The increased concentration of CO2 in the air has the effect that C3 plants such as wheat or potatoes that are very common in Germany grow faster and it increases their water use efficiency. A decreased tillering density can reduce drought stress, while a diversification of crops can reduce the risk of severe crop losses.
Ecosystem measures are relevant for animal husbandry, too: through appropriate breeding measures, livestock species can be adapted to climate change. Such measures can, for example, help to improve their heat tolerance and resistance to parasites and diseases. Moreover, the introduction of new breeds and crossbreeds has to be taken into consideration. In addition, planting drought-tolerant grasses can ensure the greening of meadows.

Legal, political and management measures

Both the federal government and the EU promote adaptation measures in agriculture. At the European level, for example, the European Agricultural Fund for Rural Development (EAFRD) is a financing instrument, which is meant to increase the quality of life in rural areas and promote the diversity of the rural economy. In Germany, the financing of such projects is organised by the Joint Task for the Improvement of Agricultural Structures and Coastal Protection (">GAK). Especially the promotion of the irrigation infrastructure is carried out by the GAK.

In addition, the federal government relies on a networking of actors in order to adapt agriculture to climate change: The transfer of knowledge on adapted land management, animal husbandry, nutrition and health is promoted, for example, in the context of dialogue projects with experts.

In addition, various management measures are pursued in Germany: A soil-conserving and water-saving agriculture can counteract crop losses due to changes in precipitation amounts and the resulting changes of the groundwater and soil water balance. Possible alternatives for the efficient use of water include the mulching process in which mowed plant parts are shredded and left on the mown area or the plough-less tillage. Compared with conventional methods, the use of both processes reduces the water consumption through evaporation, reduces erosion risks and the release of carbon. In addition, rain can drain away better which thus prevents floods.

Also fertilising management and plant protection have to be adapted to the changing conditions. In order to ensure a more environmentally sound and need-based fertilisation, the share of nitrogen in fertilisers should increase along with the increasing amount of CO2 in the air. However, at the same time it has to be balanced with the rising water needs of plants that results from the additional nitrogen. If this is the case, higher yields can be realised. In addition, threats posed by (new) pests must be recognised and banned as early as possible.

In the context of livestock husbandry, meadow management measures should be employed to meet the impacts of climate change. Measures such as adjusting the use intensity or shorter or nocturnal grazing can prevent arid and cropped meadows and protect animals from heat stress.

If you are interested in obtaining information about concrete impacts of climate change in the field of action agriculture, please click here.

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