Soluble salts primarily originate from naturally occurring minerals and human-introduced materials within soil and growing media.
Soluble salts are chemical compounds that readily dissolve in water. While essential in small amounts for plant nutrition, their accumulation can lead to salinity issues, impacting plant growth and soil structure. Identifying the sources helps in managing salt levels effectively.
Key Sources of Soluble Salts
Based on common contributors in soils and soilless media, the primary sources of soluble salts include:
- Commercial Fertilizers: Many fertilizers contain essential nutrients in salt forms (e.g., potassium chloride, ammonium nitrate) designed to be soluble and available to plants. Over-application or improper use can lead to salt buildup.
- Animal Manures: Especially prevalent in enclosed growing environments like high tunnels, animal manures can contain significant levels of soluble salts depending on the animal's diet and bedding materials.
- Soil Organic Matter: The natural decomposition of organic matter in soil releases various soluble compounds, some of which are salts.
- Composts: Compost created from diverse organic materials can inherit and concentrate soluble salts present in the source materials.
- Runoff from Salt or Ice-Melt Areas: In colder climates, runoff from areas treated with road salt or other ice-melt products can carry high concentrations of salts into adjacent soils and waterways.
- Irrigation Water: Water sources containing high levels of dissolved minerals, such as ground water or recycled water, can introduce significant amounts of soluble salts over time, particularly in regions with high evaporation rates.
These diverse sources contribute to the overall salt concentration in the root zone, making monitoring and management important for healthy plant production, especially in controlled environments or areas with limited rainfall.
