Studies on the Shape of Porous Pipe under Cultivated Condition

Experimental studies on sub-irrigation method (VIII)

Abstract

This study was carried out to decide the optimum type of porous pipe which was used for the sub-irrigation method by use of the negat ive pressure difference under the crop cultivation. The three kinds of porous pipes, that is, torus porous pipes, cylindrical porous pipes, and pod porous pipes were used for the experiments and 10 plants of Melon (Cucumis melo L. cultivar ‘Andes’) were planted to one experimental plot. Also, the soil used in the experiments is called Fudai field surface soil, and its texture is of the loam type.
The results obtained are as follows.
1) Water supply which was necessary to grow melons could be insured by use of cylindrical porous and torus porous pipes.
2) Water which was excluded from cylindrical porous or torus porous pipes was clarified enough to spread sufficiently to the roots of the melons.
3) The merit by using torus porous pipe was clarified to be able to insure much water supply and spread sufficient water to the roots, but it was found that complete elimination of the air bubbles entrapped in torus porous pipes was pretty difficult.