Effects of Row Directions and Row Spacing on Soil Temperature, Soil Moisture, Illumination and Growth of Flue-cured Tobacco

The objectives of this investigation were to study the effects of row directions and row spacing on field environment (soil temperature, soil moisture, illumination) and growth of flue-cured tobacco (cv. Yunyan 87). The experiment was a split plot design with row direction as main plot and row spacing as subplot. The results showed that the soil temperature of ridge of S-N direction was higher than that of E-W direction, but the soil moisture was lower than S-N direction. Between the different lines, the illumination of E-W direction was better than S-N direction, while among plants of same line in S-N direction was better than E-W direction. Meanwhile, tobacco in S-N direction developed earlier, grew better than E-W direction, and the net photosynthetic rate was slightly higher than E-W direction. Row spacing had no significant effect on soil temperature and net photosynthetic rate, but when row spacing was 1.1-1.4×0.5 m, it was better in keeping soil moisture. And when row spacing was 1.2 m, the illumination was poor. The study indicates that planting flue-cured tobacco by S-N direction was better than E-W direction in the middle latitude area of South Anhui.