Micro-Meteorological Conditions and Growth of Crop Plants on a Slope Ground as Influenced by Windbreaks

[摘要] In the previous paper the author reported of the high efficacy of the method of deflecting wind direction artificially by means of setting windbreaks at suitable places for protecting field crops from wind damages on a hilly land. In the present report he deals with some results of the experiments on the micro-meteorological conditions and the plant growth on a field protected with such a method from severe winds on a slope. 1) The slope where he carried out the experiment was a southern slope of an isolated hill (58m above the sea-level) as shown in Fig 1. There stood an embankment having been built at the protrusion of the slope. It served to change the direction of prevailing westerlies consequently producing large calm areas at the leeward of it. 2) In the day time the above-mentioned calm areas (2, 3, 4, 5 and 6 in Fig. 1) were found higher than the windy fields (1, 7, 8 and 9 in Fig. 1) in their air temperatures near the ground and more remarkably so in the ground surface temperatures. 3) In the night, at the level land, the protected fields were usually lower than the windy fields in air temperature near the ground. However, at the slope, such a phenomenon could not found in the diurnal changes of air temperature near the ground and in the daily minimum air be temperature during the long period of observation. (See Fig. 2.) 4) The growth of pea plants and horse-bean plants raised on the protected and non-protected fields respectively on the slope and on the level ground were investigated comparatively. It was elucidated that both on the slope and on the level land the plant growth was always better at the protected fields than at the non-protected windy fields. The difference due to the protection was larger on the slope than on the level land. (See Fig. 3.)

[学科分类] 农业科学（综合）