Soil assessment — water retention capacity (HFCs), regionally assessed

The field capacity in the effective root space is an indicator for the assessment of the soil as part of the water balance and is assessed by its water retention capacity. High tone, slip and humus content results in high field capacity and vice versa. The field capacity can be limited by a high groundwater level as it limits the effective root space. The lower the field capacity, the less water can be retained in times of rainfall and partly re-provided in low-weather times, and the faster it comes to leaching in times of precipitation, i.e. groundwater formation. The field capacity assesses a natural soil function according to § 2(2) of the BBodSchG, in accordance with point 1.b) as part of the natural balance, in particular with its water and nutrient cycles. The criterion chosen for this is the general water balance ratios with the characteristic field capacity in the effective root space. The maps are available for the following scales: — 1: 1,000-10.000 for high-resolution or parcel-focused planning, — 1: 10.001-35,000 for community-level planning, — 1: 35.001-100,000 for planning in larger regions, — 1: 100.001-350,000 for nationally differentiated planning, — 1: 350.001-1000,000 for nationwide planning. In this diagram, the field capacity is classified regionally. Under the heading ‘Soil assessment — Water retention capacity (FKwe), evaluated nationwide’, there is still a classification of field capacity that uniformly presents field capacity across natural boundaries across the country.