Abstract. Parachute rice transplanting is a simple and practical rice transplanting method. It
can be done manually or mechanically, with various possible designs of machines or tools.
This research aimed at quantitatively formulating related factors to the planting depth and
standing of rice seedling. Parachute seedlings of rice were grown at several sizes of parachute
soil bulb sizes. The trays were specially designed with a 3D printer having bulb sizes 7, 8, 9,
10 mm in square sides and 15 mm depth. At seedling ages of 8-12 days after sowing the
seedling bulbs were drops into puddled soil. Soil hardness was set at 3 levels of hardness,
measured in hardness index using golf ball test. Angle of dropping was set at 3 levels: 0o
, 30o
and 45o
from the vertical axis. The height of droppings was set at 100 cm, 75 cm, and 50 cm.
The relationship between bulb size, height of dropping, soil hardness, dropping angle and
planting depth was formulated with ANN. Most of input variables did not significantly affect
the planting depth, except that hard soil significantly differs from mild soil and soft soil. The
dropping also resulted in various positions of the planted seedlings: vertical standing, sloped,
and falling. However, at any position of the planted seedlings, the seedlings would recover
themselves into normally vertical position. With this result, the design of planting machinery,
as well as the manual planting operation, can be made easier.