Effects of soil water content on growth, biomass partition and nutrient uptake of tobacco

Effects of different soil water contents on the nutrient uptake and growth of flue-cured tobacco were studied under the pot cultivation. The results show that with the increase of soil moisture, the height and biomass of tobacco are increased, and the amplitude increments are leafstemroot, while the root to shoot ratios are inversely proportional to the water content, which reflects the characteristics of the responses of tobacco growing to various soil moisture contents. Chlorophyll has different responses to soil moisture content in different growing periods, and the most optimum soil moisture for Chlorophyll at different growing periods are 70%75%, 80%85% and 50%55%, respectively. The uptakes of N and K are all significantly greater than that of P in the five treatments, with the decrease of soil water content, the nutrient uptakes of roots and stems are increased in varying degrees when the moisture content is less than the optimum level that required by tobacco, while the uptakes of leaves are declined. While in the case of excessive soil moisture content, the nutrients uptakes (N, P, K) of roots, stems and leaves are significantly reduced in each period.