Umweltbundesamt
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Agriculture is particularly affected by the impacts of climate change. Appropriate adaptation measures can curb yield losses and make an important contribution to climate change mitigation.
In the field of action agriculture (crop production), adaptation activities can start with the type of soil cultivation and treatment, irrigation, the choice of plant varieties and frost protection. In addition, technical measures are relevant that improve weather forecasts and warning systems and enable farmers to adapt to weather changes and extreme events in time and to initiate protective measures.
With regard to the increasing heat stress in the summer months, early cereal varieties can be used, although negative effects on grain yields are to be expected due to the lower radiation at the earlier stage of the growing season. Climate changes also allow the introduction of crop varieties that have hardly been cultivated in Germany so far. Particularly suitable are certain varieties of corn, millet and other warmth-loving species that use water effectively. For example, the cultivation of soybeans has expanded significantly in Germany in recent years.
In arable farming, fruit cultivation and viticulture, various measures are used to counter the risk of late frost. In general, cultivation in frosty areas (e.g. valleys, sinks) should be avoided and the variety selection (winter hardiness) should be adapted to the respective location. In arable farming, more winter-hardy varieties or even crops (e.g. rye) can be cultivated to avoid cold frost damage. In fruit cultivation, frost protection irrigation has proven to be an effective measure. In the Lower Elbe region near Hamburg, for example, about 75% of the fruit-cultivation area is equipped with frost protection irrigation. Here, fruit trees are iced by continuous sprinkling during frost. The heat energy released when the water freezes prevents the blossoms from freezing. Considerations for sprinkler irrigation are the high water and energy consumption, the provision of an adequate water supply, and the risk of soil watering. In viticulture, wind turbines and wind machines can be used to mix cold and warm air layers to reduce the risk of late frost. In addition, frost candles can be used in the rows of vines, which can also reduce the risk of late frost through the heat generated when wind conditions are favorable.
In order to counteract the negative effects of drought stress, water-saving and site-adapted soil cultivation, irrigation measures and variety selection are primarily used in agriculture. The avoidance of plowing or conservation tillage, the cultivation of alternating plant species (crop rotation) and catch crops, the promotion of humus buildup, and year-round soil cover through undersowing or through a mulch layer can reduce the evaporation of water from the soil. In addition, these measures have other positive effects: an increase in soil fertility, a reduction in the risk of erosion by wind and water, and nitrate contamination of groundwater by binding nitrogen. Irrigation can be an effective adaptation measure in the event of increasing dry periods, in order to ensure the field emergence of crops as well as the yield level and quality of harvested products in the future. In some regions of Germany, economical cultivation of potatoes, fruit, vegetables and some specialty crops will largely be impossible in the future without irrigation. Irrigation should use water-saving irrigation methods with high water use efficiency that is controlled according to soil moisture, e.g. drip irrigation. The required additional water can be made available by removal from groundwater or surface water, water storage reservoirs, or water transfers. In Germany, the removal of irrigation water from groundwater and surface water is legally regulated by the Water Resources Act and corresponding regulations of the federal states. Given the sensitivity of plants to the combination of heat and drought, it can be assumed that the importance of irrigation in agriculture will increase in the course of climate change in Germany. Both the EU and the federal government support irrigation infrastructure in agriculture, e.g., at the European level the European Agricultural Fund for Rural Development (EAFRD) and in Germany through the Joint Task "Improvement of Agricultural Structure and Coastal Protection" (GAK). Irrigation measures should, if possible, only be promoted in areas with a sufficient supply of supplementary water, where they should focus on water-saving or efficiency-enhancing irrigation measures for reasons of resource-conserving water use.
Seed selection should also be adapted to climate change. In particular, varieties that are less vulnerable to drought and heat stress and prove robust to pests are suitable for effectively countering climate change. In general, diverse cultivation and the use of robust varieties and crop species can reduce the risk of crop failure.
As a precautionary measure against the stress factors of wetness, continuous and heavy precipitation, sites with waterlogged soil layers should be avoided in arable farming, fruit cultivation, viticulture and horticulture. This also applies to the selection of varieties sensitive to waterlogging. The measures predominantly used for areas prone to waterlogging are drainage methods, which can be underground or above ground, as drainage or ditch drainage, and free or regulated. As a cultural-technical measure, a soil cover or a greening in steep slopes can contribute to the reduction of erosion risk. Appropriate soil cultivation and wide tires for agricultural machinery help to avoid soil compaction. In orchards, vineyards and horticulture, the conclusion or promotion of an insurance policy against heavy rainfall can be considered as a management measure.
In regions where hail events occur quite frequently (e.g. southern Germany), hail protection nets are used in fruit and wine growing as a common adaptation measure. The measure is cost-intensive, but has a high degree of effectiveness and an additional benefit through bird repellency. If used on a large scale, negative ecological effects are to be expected, e.g. on biodiversity. Alternatively, farms can take out hail insurance to cover damage caused by hail.
Strong winds and storms, which can cause wind erosion, are a challenge for soil protection and thus also for agriculture (see Field of Action Soil). In addition to site-adapted tillage and the establishment of windbreak hedges, agroforestry systems (agroforestry), the joint cultivation of arable crops, grassland or special crops with trees can be an effective adaptation measure to reduce wind erosion. Such systems also increase soil fertility and water-holding capacity in the soil, create a favorable microclimate on site, and increase biodiversity.
Indicators from the DAS monitoring: Cultivation and propagation of thermophilic arable crops | Adaption the variety spectrum, maize varieties by maturity groups | Use of pesticides | Agricultural irrigation
Adaptation measures in the livestock sector are extremely important in response to the effects of climate change on livestock, particularly the consequences of heat stress on animal health and performance features such as milk production. Structural and technical measures can be considered to reduce heat input and promote heat removal in freely ventilated outdoor barns, such as consideration of the siting and orientation of new barn construction, adequately thermally insulated roofs, sufficient roof overhangs, green roofs, light-colored roof surfaces to take advantage of the albedo effect, natural shading from trees on the south side of the barns, and flexible wall designs to allow airflow to be regulated. Fully air-conditioned barns, which are characterized by a high degree of automation with regard to the control of ventilation, temperature and humidity, can be used to specifically counteract a hot spell. Aspects relevant to climate mitigation should be taken into account (e.g. low energy consumption). In barns without such automated cooling facilities, as well as in open barns, fans can be used for active cooling to increase air velocity and air exchange rate, as well as evaporative cooling measures such as cow showers and water sprinklers. In addition, an optimal drinking supply must be ensured in the barn, in the waiting yard and at other suitable locations on the farm.
Climate change also increases the risk of heat stress in grazing animals. Possible responses to this include changes in pasture management, such as the use of night grazing. In certain regions, there is the option of shifting grazing to higher cooler areas. Another suitable measure against heat stress may be to plant shade trees in the pastures.
Finally, adaptation options also exist in terms of breeding, by favoring robust breeds and breeding lines of dairy cows that are better adapted to warmer climatic conditions. This is where breeding programs for climate-adapted livestock breeds can come in. The issue should also be increasingly incorporated into education, training and agricultural consulting. As climate change progresses it may also be necessary for animal production to adapt the regulatory and subsidy framework to the changed conditions. This concerns, for example, the regulations for animal houses (insulation, ventilation) or the adaptation of regulations for organic farming (adaptation of grazing periods during periods of extreme heat).
Changing sowing dates, for example, can address the shift in seasons: Summer cereals could be sown earlier to take advantage of spring soil moisture. Winter cereals, on the other hand, should be sown later in the year so that the cold phase, which is important for cereals, does not occur too late. In the transitional phases, the use of deep-rooted crops, such as grasses, can reduce the risk of drought damage in summer and protect the soil against erosion.
Indicators from the DAS monitoring: Adaptation of management rhythms
The UBA’s motto, For our environment (“Für Mensch und Umwelt”), sums up our mission pretty well, we feel. In this video we give an insight into our work.
