LW-R-4: Cultivation of thermophilic crops | Umweltbundesamt

LW-R-4: Cultivation of thermophilic crops

The cultivation areas used for growing the thermophilic crops of soy and durum wheat are on the increase. The decisive factor for this are the agropolitical framework conditions. As a vegetarian protein alternative, the cultivation of soy, in particular,  is strongly promoted. However, more favourable climate conditions are an important prerequisite for the expansion of this crop. The cultivation of grain maize is generally more economic where higher amounts of warmth are available.

Cultivation terrain of thermophilic crops is expanding

Warmer weather conditions and an increasing choice of suitable varieties (cf. Indicator LW-R-2) as well as increasing market demand have led to the cultivation of soy, durum wheat and also maize increasingly gaining in interest in Germany. As far as soybeans are concerned, the cultivation terrain has doubled since 2016 when the species began to be recorded statistically. In 2021 soybeans were grown on roughly 34,200 ha; by 2022 that extent had already increased to 51,500 ha. The cultivation hotspots are located in Bavaria and Baden-Württemberg where soybeans have by now overtaken peas, broad beans and lupins, thus becoming the leading grain legume in cultivation. Nevertheless, domestic production can only cover 3 % of annual demand. Within the framework of the BMEL’s protein plant strategy, the cultivation of legumes receives extensive funding in Germany. Latterly, the funding allocated to the protein planting strategy for 2023 was increased by 3 million Euros to a total of 8.6 million Euros. The current Federal government pursues an objective of strengthening vegetable food alternatives. Thanks to the existence of attractive sales channels and high producer prices, there has been – currently and for the near future – mounting interest in the cultivation and in the seed material of soybeans, both in conventional and ecological agriculture. The favourable market-political conditions are of crucial importance for the expansion of soy cultivation terrain. At the same time, advantageous weather conditions help making the cultivation of this crop more attractive in Germany.

The European hotspots for cultivation of thermophilic and relatively drought-tolerant durum wheat are located, above all, in Spain, France and Italy. In Germany this species has been cultivated for many years as a niche crop. The largest cultivation areas are nowadays in Saxony-Anhalt and Thuringia. However, by now durum wheat is also cultivated in the warmer regions of Bavaria, Baden-Württemberg and Rhineland-Palatinate. 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 marketed as semolina for pasta production. Therefore any flaws in the harvested product – which manifest clearly as black spots – exclude the product from sale.

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 summer droughts become more regular, the conditions for successful cultivation in this country might improve in the long term. In 2022 durum wheat was grown on a terrain of 40,800 ha – the equivalent of scarcely 0.37 % of the total cultivation terrain used for cereals, plants harvested green, pulses, root crops and industrial crops. Given the increased certification of crop varieties and the production of seed materials for winter durum, it is to be expected that there will be an expansion, given that winter durum provides distinctly higher yields than summer durum.

In view of the fact that durum grain is very firm, special rollers are required for grinding, and they are not readily available in every mill. However, having appropriate mills in the vicinity, is an important prerequisite for expanding the cultivation of durum wheat. To date, there are only six durum wheat mills in Germany capable of grinding durum wheat to produce semolina¹¹². As shown above, climate change plays an important – albeit not the only crucial – role in furthering a further development of the terrain for durum wheat cultivation.

Maize is a crop that has been cultivated in Germany for a long time. Contrary to using the whole plant as silage maize for animal fodder and energy generation, grain maize – using only the cob for animal feed or human food production – depends on comparatively high amounts of warmth for the crop to ripen. The expansion of the cultivation terrain is therefore linked partly to more favourable weather patterns. Consequently, in respect of grain maize, the prospects of livestock breeding have to be taken into account, because the demand for fodder will shrink as livestock (especially pig) numbers decrease. However, this development is not influenced by the cultivation of energy plants. As soon as it has been harvested, grain maize has to be dried in order to lower its water content to roughly 14.5 %. Hence the costs of drying are the crucial profitability factor, especially in view of mounting energy prices. The more favourable the weather patterns and the drier the grain maize as it comes in from the field, the greater the commercial gain from its cultivation. Moreover, the temperature increase over recent years led to earlier ripening and harvesting of grain maize. The fact that fields were cleared earlier benefitted the subsequent cultivation of winter wheat, thus facilitating the scheduling of crop rotation. However, when conditions become very dry, grain maize will suffer too. Consequently, the grain maize harvest of 2018 was disastrous. In summer 2019, however, the harvest was unexpectedly good as a result of rainfall in late summer, thus increasing yields.

There is some ambiguity in interpreting the relationships between the expansion of the cultivation area for grain maize and climate patterns. This is because grain maize can be processed into a moist silage feed known as corn-cob mix (CCM). In the production of CCM both the grains and the centre of the cob are utilised. For this type of use, favourable drying conditions are commercially less important than for the use of grain maize for ripening. From 2010 onwards statistics no longer differentiate between naturally ripened grain maize and CCM. Prior to this statistic amalgamation, the extent of the total terrain used for grain maize cultivation was constantly three to four times greater than that used for CCM, so the combined grain maize / CCM data also allow conclusions to be drawn. Basically, it is fair to say that – to explain the development of the cultivation terrain for grain maize in recent years in the light of prevailing weather conditions – has its limitations. For the future, it is to be expected that the current agropolitical framework will continue to play an important role. Given that grain maize responds relatively little to reducing the amount of nitrogen fertiliser, it might gain in attractiveness as a summer crop.

The cultivation terrain of sorghum, which is originating from the Sahel region, is not yet recorded separately in agricultural statistics. So far, temperatures in Germany have been too low for cultivation, so the areas under cultivation are still very small. However, given that by now there is also the development of indigenous varieties taking place (cf. Indicator LW-R-2), the interest in cultivating this specific variety might increase.

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