Soil and water

Soil is the basis of sustainable agriculture. What not many take into consideration, however - at least not at first - is that the soil is also important for our water system. The soil can absorb water like a sponge in wet times and can supply water during drought. In addition, water is filtered in the soil, so that it also contributes to the quality of the water. The soil is therefore an important pivot in Dutch water management. Climate change, with more extreme weather events, will only make this function of the soil even more important.

Soil management

Good soil management is necessary in order to be able to use the water buffer function of the soil optimally. Soil structure, keeping the soil covered, organic matter, and the prevention of disturbing layers play a role in this. All is interconnected. A late harvest under wet conditions can cause a disturbing layer in the plot, which worsens the water balance. The cultivation of deep-rooted crops such as cereals and legumes can actually improve water infiltration into the ground. It is important to look closely at the soil. Making a profile pit can often say a lot about how soil management can be improved. In many projects, the Louis Bolk Institute collaborates with farmers to improve their understanding of the soil in this way.

Retaining and using water

Retaining water in winter, to be able to use it in summer, is an important function of the soil. In order to be able to absorb a lot of water during rainfall, both a high organic matter content and a good soil structure are important. Water can then infiltrate into deeper soil layers without the formation of puddles. By retaining water locally, less supply of water is required during dry periods when irrigation is desired. The Louis Bolk Institute works together with farmers, water boards, and governments to improve the water management of agricultural plots.

Water use must also be more efficient to make agriculture climate-adaptive. Various new techniques for sprinkling, water storage and irrigation can contribute to this. It is important to investigate how these techniques also influence other functions of the soil. For example, reel irrigation has a different impact on the soil structure than drip irrigation. Together with water companies, farmers, and governments, we investigate new techniques for water use and look at how these can contribute to a sustainable and climate-adaptive system.

Water quality

The soil largely determines the quality of the water that ends up in adjacent waterways. With good water infiltration, excess nutrients and chemicals remain in the soil, such that clean water reaches the waterways. This is important for biodiversity in canals, lakes and rivers, but also for the quality of our drinking water. In addition to good soil management, we encourage the use of buffer zones with herb-rich vegetation along waterways, in order to reduce drift and runoff, and to offer biodiversity a place in the agricultural landscape. We are investigating how these buffer zones and the adjacent canals can best be managed to provide benefits for farmers, water and biodiversity.

Manure and Bokashii

The main priority of the organic fertiliser projects is the search for the right fertilisation per type of crop, cultivation, and soil type while taking soil quality and yield into account. In addition, research is being conducted into the possibilities and effects of relatively new organic fertilisers such as bokashi. But what makes bokashi good bokashi? How does this fermentation work, what are the factors that contribute to a successful bokashi and, above all, what is the effect of bokashi on soil quality?

Drip irrigation

The Louis Bolk Institute is working in collaboration with Acacia Water on investigating various irrigation methods (including traditional irrigation via the reel, above-ground drip irrigation, underground drip irrigation, irrigation via drainage pipes and no irrigation (control)). The focus is mainly on water consumption and crop yield. Soil quality and crop quality are also examined.