Study of characteristic environments and increasing productivity of the field crops in sand dunes and arid lands

在墨西哥下加利福尼亚沿海沙丘，在极高温度和极低湿度条件下，进行了蔬菜增产研究的基础研究：欧洲油菜f.et. var.komatuna Makino），萝卜（萝卜L.），Bekana、小白菜（Brassica chinensis L.）、结球莴苣（lactuca sativa L.）var capitata L.），还有格林德比在栽培过程中，试验了滴灌、渗灌、保水剂、控水控灌等节水栽培技术。同时，我们调查了播种床中植物生长的优质水，这是通过除湿机从空气湿度中获得的。在下加利福尼亚，地下水的E. C.值，1442 us/cm，但除湿水很好，E.C.，266us/cm。除湿水处理的植株生长显著优于地下水处理，叶片重分别是清水处理的1.9倍和小白菜的1.6倍。在9种保水物质中，小白菜的叶重均有所增加，其中最大效果增加了60%左右。他们在墨西哥的成绩大多数都比在日本的成绩低。由于灌溉水含盐量高，阻碍了植物的生长，因此，要想在沙漠中植树造林，就必须尽快开发新的耐盐保水物质。在相同的灌溉水条件下，灌溉频率越高，叶重和小白菜的产量越高。

In coastal sand dunes of Baja California, Mexico under very high temperature and very low humidity, we performed the basic research for the study with increasing productivity of vegetables: (Brassica campestris L. subsp.napus Hook. f.et Thoms. var.komatuna Makino), radish(Raphanus sativus L.), Bekana, Pak-choi (Brassica chinensis L.), head lettuce(lactuca sativa L. var capitata L.), and Greendebut. When we cultivated them, we tested many kinds of cultivation techniques for spending the less amount of water: the drip irrigation, the perforated irrigation, the use of water holding substances and controlling the irrihation with the frequency and the amount of water. At the same time we investigated the plants growth in seeding beds by the water of good quality, which was given from air humidity by dehumidifying machine.In Baja California the underground water had the value of E.C.,1442us/cm, but dehumidifying water was very good,E.C.,266us/cm. The plants growth by dehumidifying water was shown to be signifficantly better than that by underground water, with leaf weight by lettuse, 1.9 times and Pak-choi, 1.6 times. In 9 kinds of water holding substances the increase of the leaf weight, Pak-choi, arised and the greatest effect of them increased about 60%. Their result in Mexico mostly got the values less than the result in Japan. Because high salinity into irrigation water prevented plants growth.Then if we hope to plant trees in desert, we should quikly develop a new salt-tolerant water holding substances. When we gave the same irrigation water, we got more frequent irrigation, we got leaf weight, Pak-choi, more increasingly.