| Popis: |
To identify/assess the causes of emitter clogging and its relationship with microirrigation system management using wastewater, a drip irrigation experimental system was installed in a field located in central part of agricultural zone of Tohaku, Japan. The water quality analyses shown except of pH others chemical and composition factors of irrigation water are ranked slight. The pH of irrigation water was moderate in minimum values and ranked severe during the irrigation season. Total number of planktons in irrigation water was classified moderate in maximum concentration. The main planktons genera in irrigation water were Synedra and Asterionella with 40-350 µm length, which suggestion that the planktons even in low concentration are the main factor causes of emitter clogging in Tohaku area. The uniformity indices, Vpf, Uc, and Dra have been used to evaluate performance and to rank the emitters with respect to clogging. The values of uniformity index (Uc) indicated all emitters belong to high classification (>89%). The value of Dra indicated the emitters type 1, 2 and 7 were in the mean classification for a while during the irrigation season. The values of Vpf in most of emitter type were ranked in mean classification. The uniformity indexes and emitter’s specification shown that (i) the emitters type No. 1, 2, 3, 7, and 10 are more sensitive to kind of biological clogging for Tohaku area (ii) the filtration area in emitter’s structure is an affective factor to prevention of clogging (iii) water flow cross section and working pressure are not an affective factor to prevention of clogging in emitters solely. |
