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Pros and cons of using wastewater for irrigation

reuse of wastewater for irrigation is touted as an environmentally sound practice. But little is known about its long-term effects. A recent study from Jordan says that the frequent use of treated wastewater can affect plant growth and crop yield. Researchers say the use of wastewater has to be continuously monitored to get optimal results.

While wastewater does contain nutrients and organic matter, the researchers say its effectiveness in irrigation depends on the match beween its composition and the ecology of the soil. The study was published in the journal Desalination (Vol 215, issues 1-3).

The study analysed soil irrigated with treated municipal wastewater for two, five and 10 years. At the first site the acid content was high and salinity and organic content in the soil were found to have increased with the duration of irrigation.

The soil irrigated for a longer duration had increased presence of macronutrients, phosphorus and potassium in the top layer. Micronutrients