This study was conducted to develop a precision automatic irrigation system in a nursery by considering the problems and improvements of manual and the conventional automatic irrigation system. The amount of irrigated water between the conventional automatic irrigation system and manual irrigation was 28.7 ± 4.4 g and 14.2 ± 4.3 g, respectively, and the coefficient of variation was less than 30%. However, the coefficient of variation of the conventional automatic irrigation system of 15%, was higher than that of manual irrigation of 30%. The irrigation test using the developed uniform irrigation system attached with the nozzle of a spray angle 80° and most highest uniformity was at height 600 mm. And coefficient of variation of the irrigation uniformity at the center part was within 20%, but irrigation amount of the edge part was lower 50% and over compared to the center part. As a result of a tomato grafting seedling cultivation test using the developed uniform irrigation system, the average plant height of seedling at the edge part was 28 mm but plant height at the center part was higher as 72 mm. Therefore, it was necessary to apply additional irrigation device at the edge part. The irrigation uniformity of the edge concentrated irrigation system was investigated that the irrigation amount of the edge part was irrigated by more than 50% compared with the center part, and coefficient of variation of the irrigation amount at the center part was less than 30%. As a result of a cucumber grafting seedling cultivation test using the edge concentrated irrigation system, the plant height of seedlings in the edge and central part of cultivation bed were 24% and 26%, respectively, so irrigation uniformity was higher then the uniform irrigation system. In order to improve the uniformity of seedlings, it is necessary to adjust the height of boom according to the growth of the seedling by installing a distance sensor in the overhead watering and boom irrigation system.