On the Windbreak in the Field (IV) : ON the Influence of Various Windbreaks upon the Micro-Meteorological Condition in the Farm Field

Abstract

The writer investigated the micro-meteorological conditions in the fields using 3 kinds of windbreaks: they were the board fence, the lattice fence, and the reed fence. The outlines of the results obtained were as follows: 1. The velocity of wind. On the leewardsides of the lattice fence and of the reed fence, the velocity of wind was very small. On the contrary, on the leewardsides of the board fence, the vortex provoked there and adverse wind was severe. 2. The temperature neat the surface of earth. In the daytime, on fine weather, on such wind-weakened field as the leesardsides of the lattice fence and the reed fence, the temperature near the surface of earth is higher than the air temperature. On the open field the temperature near the surface of earth is higher than the air temperature. On the open field the temperature near the surface of earth is between both, and resembles to it which on the seewardside of the board fence. The difference above mentioned was most clearly observed on fine weather and became vague on cloudy weather. In the night the order was opposite. 3. The relative humidity. The relative humidity was compared between on the seewardside of the reed fence and on the open field. The former is higher than the latter every time except a few hours near the noon. 4. The moisture of surface soil. Evaporation on the open field where the wind is severe is larger than that on the field where the wind is weakened. Accordingly the moisture of surface soil decrease according to the force of wind. 5. The others. The author also observed great differences among them on the flying soil, the frost, and the accumulated snow.