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州沿海沙丘上，在极高温度和极低湿度下，我们进行了基础研究，以提高蔬菜的产量：(Brassica campestris L.subsp.napus Hook)。F.et Thoms.、萝卜(Raphanus Sativus L.)、贝卡纳(Bekana)、小白菜(Pak-Choi)、结球生菜(Lactuca sativa L.var Capitata L.)和绿头菜(GreendeBut)。在栽培时，我们试验了多种节水栽培技术：滴灌、穿孔灌溉、保水剂的使用以及用水的频率和水量来控制暴发。同时，用除湿机从空气湿度中获得的优质水对苗床内植物的生长进行了调查，在下加利福尼亚州，地下水的E.C.值为1442us/cm，但除湿水的E.C.值很好，为266us/cm。除湿水处理的植株生长明显好于地下水处理，叶重分别是生菜的1.9倍和白菜的1.6倍。在9种保水剂中，白菜叶重增加幅度最大，增加幅度约为60%。他们在墨西哥的结果大多低于在日本的结果。因为灌溉水中的高盐度阻碍了植物的生长。那么，如果我们希望在沙漠中植树，我们应该迅速开发一种新的耐盐性保水物质。在灌水量相同的情况下，灌水次数越频繁，叶重、白菜数越大。

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.