Water quality and distribution uniformity in drip/trickle irrigation systems

The clogging of emitters is a major problem encountered in drip/trickle irrigation systems, as partial or complete clogging reduces application uniformity. Clogging is closely related to the quality of the water used. Despite the quantity of research reported in literature concerning the quality treatment and distribution uniformity of irrigation water, the problem still remains of accurately foreseeing the clogging risk on the basis of the irrigation water quality and the corresponding effects on emitter flow rate in causing lack of uniformity in the field. The paper reports an investigation performed in the field on a number of irrigation systems in Southern Italy, with the aim of determining parameters expressing clogging and studying the relationships between the latter and water quality. The results obtained permitted identification of both some field performance indices which can be used to evaluate clogging and water quality factors which can be used to classify the clogging hazard rating of emitters. Indications can be drawn about the number of emitters to be tested in the field and also the relationships between clogging and emitter position in the lateral. (C) 1998 Silsoe Research Institute.