MOISTURE CHARACTERISTICS OF THE ARTIFICIAL MEDIA
MOISTURE CHARACTERISTICS OF THE ARTIFICIAL MEDIA COMPOSED OF RICE HUSK AND DEMONSTRATION ON SWEET POTATO CULTIVATION
S.Yamanaka1, A.Tanaka2, K. Nakaji3
1Department of Bioproduction Environmental Science, Kyushu University, 6-10-1,
Hakozaki, Higashi-ku, Fukuoka 812-8581, Japan. firstname.lastname@example.org
2Coastal Bioenvironment Center, Saga University, 152-1, Shonan-cho, Karatsu 847-0021,
Saga, Japan. email@example.com
3University Farm, Kyushu University, Kasuya-cho, Kasuya-gun, Fukuoka 811-2307,
The amount of the rice husk reached 2 million tons and the rice husk of 710,000 tons was abandoned and incinerated in 2000. It is necessary to expand the use of rice husk from the viewpoint of a material cycle in ecosystem. The rice husk was investigated on the possibility as an artificial culture medium.
Moisture characteristics of the new culture media were measured and the proof examination was carried out for the sweet potato cultivation. The indexes of water retentivity ? and hydraulic conductivity ? of culture media were determined using the centrifugal method and the suction method. The values of 100% rice husk were the smallest in culture media respectively, and increased in order of 100% crushed rice husk and 100% rice husk charcoal. These values influence the water-supplying-power of rice husk to plant roots. Four kinds of cultivation bed filled with different type of rice husk were made, and sweet potato was grown for 142 days. The root grown in rice husk media penetrated into the soil under and side of the cultivation bed to supplement the lack of moisture. It was clarified that the growth of sweet potato was vigorous through the cultivation experiment and the rice husk was useful as a good culture media.
Keywords: Rice husk, Culture medium, Hydraulic conductivity, Water retentivity.