The treatment of irrigation water is not yet mandatory in Poland. In many countries, irrigation water quality standards have been implemented, protecting crops from the negative effects of using hard or saline water.
The main effect of using untreated water is soil salinisation and chemical degradation. Too high a content of mineral salts, especially salts that are difficult to leach from the soil, e.g. calcium and iron compounds, causes the soil’s sorption complex to fill up to such an extent that its ability to absorb, accumulate and release compounds that are beneficial to plant growth decreases. Occasionally, toxic concentrations of accumulated salts may occur for plants, e.g. as a result of long-term irrigation with iron-rich water mostly from deep-sea springs.
Water treatment can be divided into three basic methods: mechanical, chemical and exchange. Depending on the chemical composition of the water used for irrigation, appropriate treatment methods should be used.