HORSCH Live 2024
Another HORSCH Live series started in January under the motto “Weather extremes - can modern production technology counter them?” A total of four presentations on current topics held by professional experts were streamed.
Prof. Dr. Hansgeorg Schönberger
The first speaker was Prof. Dr. Hansgeorg Schönberger with the topic: “Wheat cultivation under increasing weather extremes - why singulate?”
The climate is currently changing. The problem is not the change itself, but its speed and the weather extremes that are involved. The consequence for crop farming is: mild winters and thus weaker vernalisation which makes plants more sensitive. Generative development takes place in spring in warmer, almost hot conditions which is detrimental to the yield output.
Fit and healthy plants can better adapt to weather extremes. The prerequisite is a well-developed root system. The plant needs a good environment, a sufficiently large and homogeneous root and standing area as well as an adequate supply with nutrients. In this respect, the optimum placement of the grains plays an essential role. If the seed is placed too deeply, the root develops fewer fine roots and thus the uptake of water and nutrients is worse. If the seed is placed too shallowly, it is less likely to emerge and there is the risk of bird or herbicide damage. In case of a horizontal placement, there should be a maximum distance of 3 cm around the grain. If the grains are closer together, they will compete for water and will not emerge evenly. If the plant has too much space, it tillers excessively, and the intra-plant competition increases.
The objective is to achieve even populations as they can cope much better with drought stress situations and are less sensitive to weather extremes – arguments in favour of single grain seeding as it ensures homogeneity with regard to standing area and development and thus contributes to yield security.
Prof. Dr. Bernhard Bauer
Precision Farming has been a topic in agriculture for about 25 years but has not yet been able to establish itself comprehensively. It all started with VariableRate application followed by applications in the crop care sector to site-specific seeding. In his speech, Prof. Dr. Bernhard Bauer wonders if the climate change can act as a catalyser in this respect. The motivation of the farms to implement these methods among others are that work processes are facilitated and efficiency when using inputs like fertilisers and crop care agents is increased. This does not only play a role with regard to economy but also with regard to society.
“The climate change will even increase the site-specific differences in the field,” Prof. Dr. Bauer explains. In areas where the water storage capacity is worse and the yields collapse in case of drought, site-specific cultivation can be a solution. In dry periods when the plant is exposed to stress, the application of growth regulators for example has to be reduced resp. abandoned completely in areas with a low yield potential. At the moment however, it is difficult the establish this comprehensively in practice. One point that is much discussed by politicians and society is the site-specific nutrient fertilisation. At present, however, the market does not provide an appropriate method for integrating the site-specific fertiliser quantity in an application map.
Experiences and tests with site-specific seeding in conventional farms do not achieve higher yields. In organic farms, however, there was a significant increase in yield with a variable seed rate between 300 and 400 grains. One reason could be that population management that is influenced by nutrient fertilisation and growth regulators influences the spike density to a greater extent than site-specific seeding.
All in all, site-specific cultivation will raise the yield level a little bit. In the future, the effects have to become more transparent so that they can be evaluated better and optimised in the next step.
Dr. Ludwig Lichtenegger
Dr. Ludwig Lichtenegger spoke about the topic “Alternating wet and dry periods – how does potash work in the soil and in the plant?” and started with the weather conditions of the past years. Lasting wet and dry periods were and still are a challenge for arable farming and more and more frequently determine the weather. In this speech, he concentrated on the question what potash does in the soil, how the availability can be assessed and how nutrient uptake by the plant works.
Potassium is a mass element that is absorbed via diffusion. Wet periods release potassium from the clay mineral, dry periods result in the shrinking of the clay minerals and in the fixing of nutrients. Potassium is a main nutrient that is involved in a lot of enzymatic reactions and is responsible for the regulation of the stromata. It also plays a major role in photosynthesis and strengthens the resistance of the plant. Crops with a large leaf mass and a large fruiting body need a particularly high amount of potassium.
The availability of potassium in the soil is significantly influenced by the nutrient content in the soil as well as the clay content of the cation exchange capacity (CEC) and depends on the presence of soil water. Moreover, the nutrient antagonists in fertilisation have to be taken into account (lime-potash law, potash-magnesium antagonism). He also discussed the test results among others with regard to yield and to the water utilisation efficiency of winter wheat as a function of the potassium supply. He illustrated that potassium increases the water utilisation efficiency, a fact that will become more and more relevant in the future.
Prof. Dr. Georg Guggenberger
At the beginning of his presentation, Prof. Dr. Georg Guggenberger defined the term humus: humus is the total part of soil organic matter. The includes dead crop material as well as material that is converted microbially. Humus has a whole range of positive aspects – it is a source of nutrients and stores water. Moreover, humus binds carbon dioxide which then is no longer available as CO2 in the atmosphere. “This means: if we practice humus management in our fields, we also do something against the climate change“, he explains. Especially as humus is essential for the productivity of arable soils.
It has to be the objective to maintain the current humus content in the soil which is a real challenge with regard to the decreasing yields in dry periods and the resulting decrease of spreading material and organic matter in the soil. Therefore, an active soil management to build up humus is important especially in dry regions.
Catch crops are one possibility. A longer catch crop cultivation accumulates more organic matter. It became apparent that the soil was better developed and that nutrients are absorbed much better in autumn. The more optimised the catch crop mixture, the higher the carbon sequestration in the soil. In addition, the cultivation of catch crops allows for using the released root exudates to carry out a nutrient management. The different composition of microorganisms is then continued in the main crop. The better the catch crop management, the more diverse is the microbial composition of the soil. “If there is a diverse microbial community, we do not only have more humus but also a more robust system that is more resilient to drought or pathogenic fungi. This is the objective we should want to achieve.”
The speeches are available under horsch.com/live in german language.