jordkemi

Jordkemi, or soil chemistry, is the branch of science that studies the chemical properties and processes of soils. It examines how minerals, organic matter, water, and gases interact to control the availability of nutrients to plants and the fate of contaminants. The discipline integrates aspects of inorganic chemistry, organic chemistry, and mineralogy to explain soil fertility, structure, and environmental behavior.

Key concepts include soil solution chemistry, pH and acidity, and cation exchange capacity (CEC) with base saturation. Adsorption and desorption processes control how nutrients and contaminants move between solid and liquid phases. Redox potential, temperature, and moisture influence chemical reactions. Soils contain minerals such as clays and iron/aluminum oxides that determine sorption characteristics, while organic matter modulates reactivity and nutrient holding capacity. Major nutrients (nitrogen, phosphorus, potassium) and micronutrients are studied in terms of their availability, mobility, and interactions.

Common methods involve soil sampling and laboratory analysis to determine pH, exchangeable cations, available phosphorus (via Olsen or Bray methods), potassium, base saturation, and total organic carbon. Spectroscopic and chromatographic techniques, as well as mineralogical analyses by X-ray diffraction or Mössbauer spectroscopy, help identify chemical forms and binding environments. Models of soil solution chemistry predict nutrient availability and contaminant behavior under changing pH, salinity, and moisture conditions.

Applications of jordkemi include guiding fertilizer recommendations, optimizing crop production, and assessing environmental risks such as groundwater contamination, leaching of nitrates, or heavy metal mobility. It also informs land management, remediation of polluted sites, and carbon cycling in soils through stabilization and mineralization processes.

Jordkemi intersects with soil science, agronomy, environmental science, and geochemistry. It is taught in universities as part of agronomy or geoscience programs and underpins soil health assessments and sustainable land use.