Between drought and technology: precision creates prospects

Drought and weather extremes - topics that are becoming increasingly relevant all over the world. Philipp and Constantin Horsch explain why this is not just about a lack of rainfall but also about a new understanding of how to deal with water, soil and precision in farming.

Water is more and more becoming a limiting factor in arable farming - worldwide, at all sites. And it is not just about a lack of rainfall. There rather has been a fundamental change in our understanding of how to deal with water and soil in recent years. “When talking to farmers today, the topic of drought comes up immediately,” Philipp Horsch says. A few years ago, things still were quite different. 

Climate researchers confirm this perception: it is not the total amount of rainfall that has changed, but its distribution. Rainfall is more concentrated - or does not occur at all for weeks. Extreme weather conditions remain stable for longer, areas of high and low pressure remain in one place, leading to pronounced periods of drought or wetness. “We are increasingly realising that it is not always related to heat, but that it is generally too dry during these phases,” Constantin Horsch adds. The pressure to generate stable yields is growing - as is the need to utilise natural resources more efficiently. Adaptability and, above all, precision are therefore becoming increasingly important.

Nutrient management and tillage

The lack of nutrients usually is the first limiting factor: “The plant always starves before it dies of thirst,” Constantin Horsch summarises. A principle that involves working in a water-saving way. Direct seeding or shallow cultivation alone are not enough. "It mainly is about making nutrients available to the plant, and this is where tillage plays an important role. The combination of catch crop cultivation and direct seeding is a step - but perhaps not completely sufficient. The soil needs oxygen and a certain soil volume to make nutrients available to the plant. And a correspondingly large soil volume can only be created by tillage. This means that the right tillage also has a major influence,” Constantin Horsch points out. “Many farms now utilise dry periods to loosen the soil at depth, on the one hand to remove soil compaction that developed over the years and, on the other hand, to add additional nutrients such as phosphorus." Tillage has to ensure an appropriate soil fabric so that the plants can access nutrients. Another aspect is to apply nutrients in a targeted way. It has become apparent that the nutrient concentration of the soil is higher in the upper layers and decreases downwards. This is not ideal, especially in dry conditions as the soil usually desiccates from above, and nutrients, thus, are available to the plant to a limited extent. “That's why we work with technology that optimises nutrient input but, above all, nutrient distribution,” Philipp Horsch says. Basically, the central goal remains to improve the water retention capacity of the soil - for example by targeted topsoil deepening, humus build-up and a well thought-out crop rotation. It is essential to not only keep water in the soil but also to be able to absorb it quickly and effectively. In this respect, soil structure plays a major role. Precision in tillage is a crucial key: “We want to work shallowly with great precision to reduce evaporation, and we want to work deeply with great precision to deposit nutrients and loosen deeply,” Philipp Horsch explains. And this exactly is the conflict: on the one hand, there is the need for targeted topsoil deepening to improve the soil structure and make nutrients available to the plant. On the other hand, there is the idea of NoTill which aims at minimising intervention to save water. Two seemingly contradictory approaches.

NoTill - the solution?

Every intervention in the soil involves a certain amount of water consumption - even if the soil is consolidated directly. So is NoTill the solution? It's not that simple according to Philipp and Constantin Horsch. It depends on many factors - soil type, crop rotation, climate. From a technical point of view, direct seeding with a disc prevailed as the placement is more precise. "In dry continental regions, we find both disc and tine machines. Nevertheless, the tine is usually more established here," Philipp Horsch explains. One advantage of the tine tool: the clearing effect is particularly beneficial in regions with a short autumn and a rapid onset of winter when crop residues hardly rot at all.

Direct seeding originally came from areas that were always far too dry or far too wet. In addition, these regions are extremely cold in winter causing heavy soils to freeze which contributes to tillage. Rain and warmth in turn lead to higher biological activity in the soil. "In Europe, winters are getting milder and milder. This is why we are probably having a harder time with direct seeding as it often reaches its limits also because of pests," Constantin Horsch says. Both agree that classic direct seeding most likely is possible on heavy soils. This requires a more intelligent crop rotation. "We need a way to deal with problem weeds and pests and still utilise the effect of direct seeding. This means interfering with the soil in a more intelligent way – this is the current approach,” Philipp Horsch explains.

Change in direct seeding

“The modern form of direct seeding is rather heading towards combining it with tillage - even within the crop rotation,” he adds. “In many regions, we are talking about crop rotation-specific direct seeding or rotational no-till,” Constantin Horsch adds. The aim is to include direct seeding intelligently and combine it with tillage within the crop rotation. For example, tillage is increasingly integrated even in traditional no-till regions such as Canada. “This was not an issue 10 years ago,” Philipp Horsch explains. The depth and precision of the treatment are essential. For every intervention costs water - especially in dry periods. "We have a wide range of point options in tillage, from intensive mixing to deep loosening, that do not bring soil to the surface. We also try to give customers the opportunity to move as little soil as possible with precision and still achieve loosening,” Constantin Horsch says. “All this can be done before seeding, but can also be combined with seeding," Philipp Horsch adds.