Team:Kyoto/Environment
1) Dr. Kumiko Ochiai (Kyoto University, Graduate school of agriculture)
In thinking about applying our device to salt damage, we first had to know about what is salt damage. We asked Dr. Ochiai, who is familiar with a salt tolerance of plants, what is salt damage and what is the cause and effect of the problem.
・There are differences depending on the plant type, but general plants can grow up to 40 mmol. Some plants, such as an ice plant, can grow even in an environment where salt concentration exceeds 100 mmol.
・Other ions that affect physical and chemical properties of soil include calcium ions and sulfide ions.
・There are three major causes of salt damage. The first is salt accumulation in the soil surface layer due to capillary phenomena by irrigated agriculture. The second is salt accumulation in the lowland due to cultivation. The third is the invasion by storm surge or tsunami.
・In order to solve the problem of salt damage of plants, there are ways to exclude Na + and raise the osmotic pressure in the living body.
Until now, we were thinking that salt damage is an independent problem, but it turned out that it is necessary to consider various things in order to think about factors causing salt damage and solutions. This will be helpful for preparing salt - resistant yeast for this year’s project
2) Prof. Norio Ishida(People's Institute of Environment)
By reading a literature and interviewing people studying in the lab, we were able to know enough fact about salt damage. However, in order for us to apply the device to the actual field, we also need to pay attention to local inputs of salt damage. This time, we asked Professor Ishida of People's Institute of Environment, who has been studying about desertification and salt damage of the Aral Sea for many years in order to hear the situation on-the-spot.
・The Middle Eastern region is a salty damage-prone area.
・Attempts to green the desert and salt damage areas have been made by planting Haloxylon which is tolerant of aridity and salt.
・In the dry area, salt accumulates around 2 mm in the soil. This is blown off by the wind, causing children to become asthma, and agricultural land becomes damaged. Will it be possible to prevent this by growing salt-resistant plants?
・In the Middle East region, they have pulled a lot of water from rivers to grow cotton in large quantities. For that reason, the river withered and the Aral Sea, which is also downstream, is drying up.
From the story of Professor Ishida, the salt damage was found to be a serious problem than we had thought until now. Especially, it was shocking to know that salt gives direct damage to human body. In addition, we found that many people are working hard on solving the problem of salt damage. I felt the necessity to aggressively communicate with these people and share information in order to impact the problem of salt damage.
3) Prof. Shinya Funakawa(Kyoto University, Graduate School of Global Environmrntal Studies)
Professor Funakawa(He is an expert on soil science and has extensively studied the circulation of elements contained in the soil)
In order to tackle salt damage, we also need to learn soil science and interactions between ions in soill. So we asked Mr. Funekawa, who is familiar with the movement of elements in the soi, and heard opinions on our project.
・Among the various kinds of ions causing salt damage,sodium ion is the worst one.
・In the place where salt damage has occurred completely, amount of salt is too much for yeast to suck up; about 1t/ha
・In areas where salt is easy to accumulate, drainage facilities (such as underdrains, etc.)
are in place, so it is possible to recover agricultural drainage.
・Some farmers recover wastewater with high salt concentration, dilute it with fresh water and reuse it again.
It was found that introduction of yeasts which absorb sodium ion is very meaningful in solving salt damage. Although it may be difficult to adapt to a serious salt damage field, we thought that there may be situation in which our device can be helpful if we take advantage of drainage facilities.
4) Kinki Regional Agricultural Administration Office
As we investigated about salt damage, I found that salt damage occurred in Tohoku region in Japan. Many agricultural lands in Tohoku region have been soaked by tsunami in the 2011 earthquake off the Pacific coast of Tohoku. So, we thought that we could apply the device to salt damage in the Tohoku region, and asked Kinki Regional Agricultural Administration Office about salt damage in Japan.
・Salt damage is not occurring too much in Japan. In Japan, salt damage occurs due to storm surge or tsunami, but salt damage is often solved naturally due to high precipitation and sufficient water from rivers
・In the Tohoku region, there are still many fields where it is difficult to resume agriculture. The reason for this is that it takes time to repair ground subsidence, improve drainage facilities, build levees, etc. In Tohoku region, salt damage is not a serious problem because it is solved together in the opportunities to repair such devastated agricultural land.
・It seems that there are not much demand in Japan, but our idea of reusing drainage water may be required for salt damage in dry areas.
Unfortunately, we found that our devices and systems are not in demand in Japan. However, in dry overseas areas there seems to be areas where our devices are needed. We decided to research overseas salt damage.
5) Prof. Haruyuki Fujimaki(Tottori University, Arid Land research center)
Prof. Haruyuki Fujimaki（Arid Land Reserch Center, Tottori University：He studies optimization of irrigation.）
As for the location of application,our devise will be in demand in overseas dry areas rather than in Japan. Our desalination system was supposed to recover the wastewater with drainage facilities, so we had to confirm that drainage facilities existed also in that area. So we asked Professor Fujimaki who is familiar with dry land irrigation agriculture by e-mail.
It was confirmed that drainage facilities exist even in dry lands in overseas. If we can combine our devise with drainage facilities well, we can apply our device to salt damage.
・In the plains of Iraq and Egypt which have been facing salt damage from old days, drainage facilities are pretty popular.
・Almost 100% of wastewater can be recovered unless it rains heavily.
・It is important how cheap we can desalinate water or soil by our yeast device.
・Research on a method of absorbing salt into halophilic plants is also being conducted. However, in order to popularize halophilic plants,
great advantage is required, and a halophilic plants which can sell in high quantity have not been found yet.
Opinion: It was confirmed that drainage facilities exist even in dry lands in overseas. If we can combine our devise with drainage facilities well, we can apply our device to salt damage.
6) Mr. Junya Onishi (JIRCAS)
In considering the introduction of the system to the dry land, it was necessary to know how agriculture and desalination are currently carried out in dry lands. So we asked Mr. Onishi of JIRCAS who is familiar with dry land, Uzbekistan, where irrigated agriculture is conducted.We heard about the present situation and problems of saline agricultural land and desalination work.
1. Since a lot of water is used for irrigation, water is apt to lack.
2. Because Fermer, which is major producer of agriculture in Uzbekistan, is be chronically short of capital. So it is very difficult to make initial investment for desalination.
3.Salt discharged by leaching in the upstream area flows out and accumulates in the downstream area.
4. Because of labor scarcities, sufficient maintenance can not be done even if the systems are introduced.
As for the salt damage in the dry area, the problem of water is the biggest factor which hinders quick solution of salt damage. However, various other obstacles are occurring, and further improvement is required for our device.