On the windbreaks on wheat and barley fields.

[摘要] In wheat or barley cultivating villages in Kanto district where violent north winds are frequent in winter, the use of windbreak is badly nedded. Formerly forest plantings were used, but recently they have often been to cut down to bring land under cultivation. So Farmers in the district use a few kind of windbreaks. They are: 1. Hedges of azalea or tea plants, running from west to east with a distance of sixty feet or less, between them. 2. Stubbles of upland rice digged up and arranged in a ridge at tbe back of wheat or barley. 3. Rows of wheat or barley straw inserted into earth at a distance of 20 feet or less. The author examined the efficiency of the three above-mentioned windbreaks at Tokyo University Farm from January to March in 1948. He conducted experiments on it on windy days, using several Birum anemometers in order to know the force of wind. The Results of Experiments: As a windbreak a hedge of dwarf plants like azalea or tea plants is not at all inferior to wood planting. Too dense a windbreak as a board fence in not good, because large and strong vortex is provoked in field which is from 1.5 to 6.5 times of the fence apart from it, which is not desirable for wheat cultivation. It is desirable that a windbreak is full of crevices as a hedge of azalea or tea plants. Two other windbreaks (No. 2 and No. 3) also were very effective although they did not look so. It was because ridges of stubble of upland rice plants shelter enough wheat or barley for violent wind, and rows of wheat or barley straw inserted into earth reduced to half of the force of wind in the fields where no windbreak was erected.

[学科分类] 农业科学（综合）