Maximum Yield USA 2014 February | Page 145

•  Test source water and irrigation water for the three types of clogging causes •  Filter large particles or aggregates, such as sand and clay, before letting the water enter the emitters •  Eliminate micro-organisms by proper disinfection and water treatment •  Prevent sedimentation of chemicals in the irrigation system by adjusting pH levels, monitoring solubility limits of fertilizers and avoiding chemical interactions between fertilizers •  Maintain the irrigation lines and emitters by periodic flushing Consult the table below to assess the clogging potential of drip emitters. Constituent “Proper chlorination and disinfection procedures are the key to controlling biological clogging of drip irrigation systems.” Level of Concern LOW MED HIGH pH < 7.0 7.0 to 8.0 > 8.0 Iron (Fe) mg/L < 0.2 0.2 to 1.5 > 1.5 Manganese (Mn) mg/L < 0.1 0.2 to 1.5 > 1.5 Hydrogen Sulfide (H2S) mg/L < 0.2 0.2 to 1.5 > 2.0 Total Dissolved Solids (TDS) mg/L < 500 0.2 to 1.5 > 2,000 Total Suspended Solids (TSS) mg/L < 500 50 to 100 > 100 Bacteria Count (#/ml) < 500 10,000 to 50,000 > 50,000 In Summary Clogging of drip emitters is a common problem with significant production and cost consequences. Fortunately, the problem can be easily avoided by testing the raw water as well as the irrigation water (particularly after fertilizers are added). The analysis of the biological, chemical and particles content of the water plays a major role in choosing appropriate prevention measures. Guy Sela is an agronomist and a chemical engineer for his innovative software company Smart Fertilizer (smart-fertilizer.com) that provides fertilizer management solutions. Applying his background in water treatment, he has lead a variety of projects on reverse osmosis, water disinfection and water purification, providing high quality water for irrigation. Maximum Yield USA  |  February 2014 143