農業，畜産

A strong earthquake hit eastern Japan on March 11th, 2011 and it lasted for 6 minutes. It triggered huge tsunami and the tsunami damaged not only houses and residents but also farmlands. There are several types of interactions between the tsunami and the farmlands. If there was a muddy (sometimes contains sulfidic materials) and/or sandy deposit under the shallow seawater or in the nearshore zone, it was transported inland. Pyrite was found in the sulfur-rich muddy deposits. There are narrowly eroded places along a road and a ridge where tsunami fell down from these micro-high sites. Moreover, the plow layer soil was lost at least partly. Thus, the deposits on the farmlands are the mixtures of the eroded plow layer soil and transported materials from the nearshore zone. The chemical interactions include the exchange reaction between Na+ in seawater and exchangeable cations in the plow layer soil, and precipitation of gypsum (CaSO4 .2H2O) as well as halite (NaCl) when the soils dry. Debris of various materials and halite, at least, must be removed to restore the damaged farmlands.

The program of research and development on the reconstruction support from the Great East Japan Earthquake on the base of the collaboration of college of technology was conducted using micro bubble technology for the water purification and the recovery of oyster culture in Ofunato Bay. The compact, lightweight and energy-saving devices having instrumentation system of 104 micro bubble generators were developed to carry out the purification and the culture. The micro bubbles in Takonoura water area of Ofunato Bay were supplied continuously during 8 months. Oyster growth-promoting was achieved by the supply of micro bubbles in Ofunato Bay and a new cultivation method of the oyster using micro bubble technology was found by the growth.

High-voltage and plasma applications for agriculture, fishery and food processing are described in this paper. Repetitive operated compact pulsed power generators with a moderate peak power were developed for the applications in several stages of agriculture and food processing. Pulsed high-voltage produces intense high-electric field which can cause some biological effects such as stress response (stimulation) and electroporation. Types of pulsed power that also have biological effects are caused with gas and water discharges which include reactive species such as ROS and RNS. The repetitive pulse discharge was used for promoting growth of the vegetables and fruits. The growth rate of the vegetables and sugar content in the strawberry harvested after the cultivation increased by the plasma irradiation to the hydroponic solution. The leaf size of the plants increased with plasma treatment time. Number of colony forming units (CFU) of R. solanacearum in the liquid fertilizer decreased from 107 to 102 CFU/mL by the plasma treatment. Seedlings with the plasma treatment were relatively healthy; in contrast, all seedlings in the positive control wilted and died from infection of R. solanacearum. The yielding rate of Shiitake mushroom (L. edodes) was improved with the high-voltage stimulation in fruit-body formation phase. The AC high-voltage keeping freshness for a relatively longer period of agricultural. The electrostatic effects can contribute to remove airborne bacteria and fungi spore from the storage house and container. This removal contributed to reduce the infection risk with fungi and bacteria. These applications can contribute a food supply chain in the world.