Anna Smetanová

Influence of biochar and terra preta substrates on wettability and erodibility of soils

Biochar (BC) and terra preta substrates (TPS) have recently been promoted as soil amendments suitable for soil stabilization, soil amelioration and long-term carbon sequestration. BC is a carbon-enriched substance produced by thermal decomposition of organic material. TPS is composed of liquid and solid organic matter, including BC, altered by acid-lactic fermentation. Their effect on wettability, soil erodibility and nutrient discharge through overland flow was studied by laboratory experiments. At water contents between 0 and 100% BC is water repellent, while TPS changes from a wettable into a repellent state. The 5 and 10 vol % mixtures of BC and 10 and 20 vol% mixtures of TPS with sand remain mainly wettable during drying but repellency maxima are shifted to higher water contents with respect to pure sand and are mainly of subcritical nature. The runoff response was dominated by infiltration properties of the substrates rather than their wettability.Only one mixtures (20% TPS) produced more runoff than sandy-loamy soil on a 15% slope at an intensity of 25 mm•h-1. The 10% BC decreased runoff by up to 40%. At higher rainfall intensities (45 and 55 mm•h-1) the 10% TPS7 was up to 35% less erodible than 10% BC. Despite the TPS containing more nutrients, nutrient discharge varied between types of nutrients, slopes, rainfall intensities and mixtures. The application of a 1 cm layer onto the soil surface instead of 10% mixtures is not recommended due to high nutrient concentrations in the runoff and the wettability of pure substrates. The usage of 10% BC in lowland areas with low frequency and low-intensity precipitation and 10% TPS7 in areas with higher rainfall intensities appears to be appropriate and commendable according to current results. However, together with reversibility of repellency, it needs to undergo further examination in the field under different environmental and land use conditions

Soil Mapping and Processes Modeling for Sustainable Land Management

Soil maps and models are indispensable tools in sustainable land management. The sustainable land use of our territory is fundamental to providing long-term socio-economic and environmental benefits. The risk of land degradation and corresponding declines in ecosystem services depends on the type of land use. Soil restoration can be extremely expensive, more than the implementation of sustainable land use practices. This is especially important in the context of climate change and the increasing pressure that a growing population places on soil resources, which is a global phenomenon. The objective of this chapter is to show the advantages of using soil mapping and modeling in sustainable land use planning and management. Soil mapping is fundamental to understand the distribution of soil properties, allowing us to implement sustainable practices in vulnerable areas and prevent land degradation. Soil indicators and models provide indispensable information for an accurate evaluation of land degradation status. Alone, or integrated with other disciplines, soil information is extremely important for understanding the causes of land degradation and implementation of sustainable land management. Accurate information and models are key tools for managers and decision makers to implement sustainable land use management policies.