Hydraulic performance experiment of an adaptive drip irrigation emitter

An adaptive drip irrigation emitter is a new type of emitter which uses the multi-use function of flow compensation and the flow adaptive. In order to examine the effect of self-adjustment automatically on an adaptive drip irrigation emitter, we studied the hydraulic performance of the type of AD-1 adaptive drip irrigation emitter under two different operating modes of the flow compensation and the flow adaptive according to the working mechanism of the adaptive drip irrigation emitter by using the negative pressure suction pump to simulate the soil suction. The tests examined the flow rate uniformity, the relation between the supply water pressure and drip flow, and the relation between simulated soil negative pressure and drip flow on the adaptive drip irrigation emitter which the simulated soil negative pressure was formed by suction pump. At the same time, we had analyzed the suitable supply water pressure. The results showed that: the adding of drip state control structure not only retained the general flow compensation characteristic of drip irrigation emitter, but also added in advantages including multi-use functions of soil moisture monitoring, intelligent controlling irrigation and automatic adjustment of drip flow. At the mode of flow compensation, the flow rate of emitter was 14.71 L/h, the coefficient of uniformity was higher, the coefficient of flow deviation was 9.79% when the supply water pressure was rated 100 kPa. At the mode of flow adaptive, the emitter can begin working normally when the two pressures were acting together, and when the supply water pressure was only 30 kPa and the minimum soil suction of 20 kPa. The coefficient of flow uniformity also stayed steady. Then we determined the minimum and the maximum suitable water supply pressure was 30 and 50 kPa respectively. Moreover, it can adjust the drip flow rate automatically and in a timely manner at the range of 0-11.22 L/h according to the actual soil moisture status at the range of suitable water supply pressure 30-50 kPa. Unlike conventional irrigation emitters, the adaptive drip irrigation emitter can better change the working mode of dripping water passively and the technology of the irrigation system was improved to the level of accurate and precision irrigation, and achieved the aim of fetching water initiatively according to the needs of the crop and soil. Therefore, all of above characteristics are not only ensuring the supply of the suitable soil moisture during the normal growth of a crop, but also promoting the further development of an irrigation system application mode in the direction of more intelligence and more automation.