Ravinnekierron

Ravinnekierron, commonly referred to in English as nutrient cycling, is the movement and transformation of chemical elements and compounds, including both inorganic forms and organic matter, within an ecosystem. It encompasses the uptake of nutrients by living organisms, their incorporation into biomass, and the release of nutrients back into the environment through decomposition, mineral weathering, and other processes. The most studied elements include nitrogen, phosphorus, carbon, sulfur, and potassium, though many other nutrients participate in cycles.

Key processes include mineralization and immobilization by microbes, plant and microbial uptake, nitrification and denitrification for nitrogen, weathering of minerals that release phosphorus and potassium, fixation of atmospheric N2, leaching and runoff that transport nutrients through soils to water bodies, volatilization, and burial or sequestration in soils and sediments. Nutrient cycling is influenced by climate, soil properties, organic matter content, land use, and biodiversity; it governs soil fertility and primary production and links terrestrial and aquatic systems through exchanges with water and the atmosphere.

In agriculture and forestry, managing ravinnekierron aims to sustain fertility while limiting losses, through practices such as balanced fertilization, crop rotations, cover crops, residue management, and composting. Excess nutrient losses can contribute to eutrophication, greenhouse gas emissions, and soil degradation. Researchers use field measurements, soil testing, and models to quantify pools and fluxes, support sustainable management, and predict responses to environmental change.