LW-R-2: Cultivation and propagation of thermophilic arable crops

The picture shows a close-up of a field with flowering millet plants. Click to enlarge
In future, thermophilic millet might become of interest for bioenergetic use.
Source: Photograph: © Isidre blanc | Wikimedia Commons/CC BY-SA 4.0

2019 Monitoring Report on the German Strategy for Adaptation to Climate Change

Table of Contents


LW-R-2: Cultivation and propagation of thermophilic arable crops

Grain maize and durum wheat are thermophilic arable crops. Subject to warmer climate conditions, their cultivation in Germany might be expanded. In the course of the past twenty years grain maize cultivation has already gained in importance. Durum wheat cultivation still plays a minor role.

The percentage shares of grain maize and CCM, grain maize and durum in arable land are shown as lines for 1991 to 2017.
LW-R-2: Cultivation and propagation of thermophilic arable crops

The percentage shares of grain maize and CCM, grain maize and durum in arable land are shown as lines for 1991 to 2017. The time series for grain maize and CCM ends in 2009 and runs parallel to the time series for grain maize until then. Both time series show a quadratically decreasing trend. The share of durum has been around 4 percent in recent years, and the trend is quadratically increasing. The multiplication area of durum in hectares is shown as a column graph and shows no trend. There are clear fluctuations between the years.

Source: StBA (main land use survey; livestock survey); BSA (Official Gazette)

Prospects for new crop species

A warmer climate and milder weather patterns open up new options for agriculture in the choice of crop species . The cultivation of thermophilic crop species in Germany might benefit from expansion provided there is sufficient market demand and the prospect of cultivation appeals to farmers from a commercial point of view. Thermophilic crop species include grain maize, sorghum, soybeans, sunflowers and durum wheat.

The cultivation of soybeans has already expanded over the past few years. In 2018 soybeans were cultivated on approximately 24,000 hectares. As part of the Federal Government’s protein plant strategy (EPS) public funding was made available from 2013 until 2018 for a network with the purpose of expanding and enhaning the cultivation and processing of soybeans. Thanks to the existence of attractive distribution channels and high producer prices, especially in the food industry (e.g. tofu), the interest in soybean cultivation and seeds in both traditional and ecological farming is on the increase. In addition, eco-farming is dependent on GMO-free soybean seeds; it is therefore to be expected that also the production of soybean seeds will attract increasing interest.

While the sorghum type of millet which originates from the Sahel region copes well with drought, it does need a lot of warmth. So far temperatures in Germany have been too low for cultivating this crop species. Millet is of particular interest in terms of energetic use. If climatic requirements for the cultivation of millet improve, this crop species might become an interesting addition or even alternative to the range of bioenergetically useful crop species. There are long-term data available for making cultivation areas suitable for growing grain maize and durum wheat. These data would lend themselves for modelling the development of thermophilic crop species. The cultivation of soybeans, however, has not been surveyed separately as a main species in soil use until 2016. Owing to its minor importance, the cultivation of millet has been covered statistically only in terms of its sum total.

Regarding grain maize the extent of cultivation areas has increased significantly in the 1990s. For its ripening grain maize depends on comparatively high amounts of warmth. Consequently, the expansion of cultivation area for this crop species is focussed on climate patterns suitable for this crop species. Grain maize is used mainly as animal feed rather than for the production of bio-energy. Consequently, the prospects of livestock breeding have to be taken into account, because fodder requirements will shrink as livestock (especially pig) numbers decrease. On the other hand, the expansion of energy crop cultivation has no bearing on this development. As soon as it has been harvested, grain maize has to be dried in order to lower its water content to approximately 14.5 %. Hence the costs of drying are the crucial profitability factor. The more favourable the weather pattern and the drier the grain maize as it comes in from the field, the greater the commercial gain from its cultivation. There is a certain amount of fuzziness in interpreting the relationships of expanding the cultivation area for grain maize and climate patterns. This is due to the fact that grain maize can be processed to make a moist silage feed known as a corn-cob mix (CCM). In the production of CCM both the grains and the cob (or ear) of the plant are utilised. In this type of use favourable drying conditions are commercially less important than in the process of letting grain maize ripen naturally. From 2010 onwards statistics no longer differentiate between naturally ripened grain maize and CCM. Having said that, the total extent of the area used for grain maize cultivation – before the statistic amalgamation of both types of cultivation – was three to four times greater than that used for CCM. It is therefore possible to use the combined grain maize / CCM data as a basis for deriving statements.

Durum wheat, too, is a thermophilic crop species and relatively drought-tolerant. Within Europe durum wheat is grown especially in Spain, France and Italy. In Germany it has been cultivated for many years as a niche crop. The largest expanses of cultivation are nowadays in Saxony-Anhalt and Thuringia. As far as cultivation is concerned, durum is a challenging and risky crop as its usability strongly depends on its freedom from fungi and diseases. Durum is predominantly used and distributed as semolina for pasta production. Therefore flaws in the harvested product – which manifest clearly as black spots – exclude the product from sale. Prevailing weather patterns – especially at harvest time – also play a very important role, and in many regions they have so far been too unpredictable to ensure successful cultivation. If weather patterns change, especially if more summer droughts become established, the conditions for successful cultivation might improve in this country. So far, however, the importance of durum cultivation, with a share of approximately only 0.25 % of the total cultivated area is rather low. It is not possible to provide an unambiguous interpretation of the slight increase which has been observed since the beginning of this millennium. In future, further indications of an increased interest in growing durum might be taken from an increased expansion of durum cultivation areas in Germany. If there is an increase in the extent of cultivation areas, this would indicate that farmers expect increased demand for seeds both domestically and from abroad. For the time being, however, no such trend is apparent.

In order to be able to make a connection between the development of cultivation area for thermophilic crop species and climate change, longer-term data series would be required, because farmers’ cultivation decisions can lead to distinct annual swings in terms of cultivated areas. First and foremost, market conditions (attainable prices, regional sales opportunities) play a major role in these matters.



LW-R-3: Adaptation of the variety spectrum



Breeding research for expanding the range of crop species in order to ensure optimal yields for ‘new’ types of crop hitherto neglected (e.g. millet or grain legumes) under future site conditions and to mitigate risks such as weather extremes,  infections with pathogens and infestations with pests (in line with the sustainability concept adopted by BMELV 2008, p. 10)