Time filter

Source Type

Hou M.,Hohai University | Shao X.,Hohai University | Chen J.,Hohai University | Wang Y.,China Tobacco Hunan Industrial Corporation in Hunan Province | And 3 more authors.
Journal of Food, Agriculture and Environment | Year: 2013

Leaves are the main harvest of the flue-cured tobaccos, thus it was more meaningful to study the leaf area index of tobaccos than that of other crops, and because the great water consumption of tobaccos, it was also important to study the water-saving and precision irrigation, in this study, we integrate them by several simulation models, a simple method to estimate tobacco LAI and soil evaporation was exploited. We study it from a two- year experiment, and the experimental design of the two years was identical, the experiment of 2010 was used to develop the calculation system, and which of 2011 was applied to examine the accuracy of the calculation system, it was found that there was an exponential relationship between LAI and the days after transplanted, also between LAI and Ea/ET, the related simulation models was established based on the relationship, the correlation coefficient of which was above 0.9, showing a favorable simulation effect. Then the calculation system based on these models was developed, the data of 2011 was plug into the system for verification, results showed that the correlation coefficient (0.993, 0.869) of the estimated value and the measured value was in a high level, and relative error was in a satisfactory extent, demonstrating that the system could well estimate the LAI and the soil evaporation, and forecast their variation tendency. In consideration of the various impact factors (mainly the meteorological factors) of the soil evaporation, it was believed that the calculation system was more applicable in the greenhouse cultivation of flue-cured tobacco. The study conclusions can provide theoretical and practical basis for the precision irrigation and yield evaluation of flue-cured tobacco. Source

Shao X.-H.,Hohai University | Wang Q.,Hohai University | Yuan Y.-B.,Research Institute of Tobacco Science in Guizhou province | Ding F.-Z.,Research Institute of Tobacco Science in Guizhou province
Applied Mechanics and Materials | Year: 2014

The experiments were carried out in lysimeters to study water consumption characteristics and water use efficiency of flue-cured tobacco under different conditions of irrigation. By comparing the T and the invalid E of the tobacco K326, it is concluded that in the period of root extending most of the irrigation water is used for the E, in the early vigorous period, plants with all of the treatments show a T higher than the E, in the late vigorous period and the maturity, this ratio remains at 50%. Based on measured data, it was shown that the amount of irrigation water in the vigorous period had the most important influence on the yield of the tobacco.The nonlinear equation of the yield and WUE is Y=-2531.3X2+6113.8X-624.49, R2=0.7324; the equation of the yield and ET is Y=4E-0.7X3-0.0032X2+8.8458X-4806.7, suggesting that the WUE is not maximized at the highest yield of flue-cured tobacco. In the highyield range, reducing irrigation appropriately could reach the harmonization of high production and water saving. © (2014) Trans Tech Publications, Switzerland. Source

Shao X.-H.,China Tobacco Hunan Industrial Corporation in Hunan Province | Shao X.-H.,Hohai University | Chen J.-N.,Hohai University | Hou M.-M.,Hohai University | And 3 more authors.
Journal of Food, Agriculture and Environment | Year: 2013

The fate of water and fertilizer N in tobacco fields was observed and analyzed under the condition of lysimeter experiments. Results showed that the proportion of plant transpiration (y1), soil evaporation (y2) and soil water storage variation (y3) accounted for the total water consumption was 60.29%-77.63%, 20.25%-37.83% and 1.49%-2.33% respectively, presenting an exponential relationship with the irrigation amount by the formula of y1= 26.55 exp (0.0026x), y2= 305.73 exp (0.0007x) and y3= 4.53 exp (0.0015x). The average fertilizer N uptake proportion of upper leaf, middle leaf and lower leaf of tobacco plant was 21.96%, 24.07% and 30.09% separately. Fertilizer N remained in soil accounted for more than 60% of the total fertilizer N application in season, which was decreased with the depth of soil layer. N loss was relatively less and significantly related to amount of N fertilizer application, with highest of T6 recorded as 24.6 kg hm-2, it seemed that both the highest irrigation amount and N application amount could lead to an easy leaching of fertilizer N. Source

Discover hidden collaborations