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Hou M.M.,Key Laboratory of Efficient Irrigation Drainage and Agricultural Soil Water Environment in Southern China | Hou M.M.,Hohai University | Shao X.H.,Key Laboratory of Efficient Irrigation Drainage and Agricultural Soil Water Environment in Southern China | Shao X.H.,Hohai University | And 7 more authors.
Advanced Materials Research | Year: 2012

Raising nitrogen utilization efficiency could not only cut the fertilizer costs, but also reduce the N loss and residual, which benefits a lot to agricultural production and environmental protection. In this experiment, the 15N tracing technique was employed in order to clear the accumulation and whereabouts of fertilizer N in flue-cured tobacco plants, besides, the tobaccos were treated by six different water-nitrogen modes, for the sake of finding out the best design with the highest nitrogen utilization efficiency. The results showed that more N application contributed to more fertilizer N accumulation, also increased the content of total N; Excess irrigation restrained the tobacco plants' absorption of fertilizer N, ultimately leading to the low utilization efficiency of nitrogen fertilizer; After apex pruning, the N offering ability of the soil was much stronger than that of nitrogen fertilizer, and the fertilizer N accounts a relatively small part for the total N in tobacco plants, the highest nitrogen utilization efficiency was 24.16%, recorded in the design of 800mm irrigation amount and 6g/plant pure N application(T2), Meanwhile, the agronomic characters and crop yield was observed, tobaccos in T2 design performed better than the average level of fieldcultivated tobaccos, the conclusions could be obtained that T2 design was preferable, which achieved the highest nitrogen utilization efficiency when ensured the normal growth and good harvest of flue-cured tobacco. © (2012) Trans Tech Publications, Switzerland. Source

Xiaohou S.,Hohai University | Chantal K.,Hohai University | Hou M.M.,Hohai University | Chen L.H.,Hohai University | Wang Y.F.,China Tobacco Hunan Industrial Corporation in Hunan Province
Journal of Food, Agriculture and Environment | Year: 2012

Lysimeter experiments were conducted to study the growth and yield quality of flue-cured tobacco plant treated by different rates of nitrogen fertilizers and irrigation water coupling. Three control treatments were set as check. The results showed that chemical fertilizers had a significant effect on the growth characteristics and yield quality of flue-cured tobacco compared to the control treatment. The nitrogen fertilizers at 120 kg hm-2 combined with 800 mm irrigation water enhanced significantly the plant height and stem girth per plant. Also, it increased the dry matter accumulation and remarkably improved the overall quality and quantity of flue-cured tobacco yield. Likewise, nitrogen fertilizers and water coupling increased chlorophyll content significantly, with better effect at 120 kg hm-2 with 800 mm irrigation water. This suggested T8 (nitrogen fertilizers at 120 kg hm-2 combined with 800 mm irrigation water) as the best one in improving plant growth and yield quality of flue-cured tobacco. Source

Hou M.M.,Hohai University | Shao X.H.,Hohai University | Chen L.H.,Hohai University | Chang T.T.,Hohai University | And 2 more authors.
Journal of Food, Agriculture and Environment | Year: 2012

To reveal the amount and distribution of fertilizer N, a self-made observation device was developed, and the 15N tracing technique was adopted. Leaching of N accounted a fairly small part for the fertilizer N gross during the growth period of tobacco, while a considerable large proportion of fertilizer N remained in soil, forming a potential threat to the surrounding environment. It was also found that 26.43% of the leaching of N was brought by runoffs, 38.12% infiltrated with the seepage water and 35.46% was in the sediment brought by seepages. The amount of N leaching had significant difference (p≤0.05) among treatments, proving that there was marked interrelationship between N leaching and N application. The analysis of fertilizer N accumulation in tobacco plants confirmed the average proportion of fertilizer N in leaf, lateral bud+ blossom, stem and root: 45.37%, 22.26%, 22.19% and 10.18%, respectively. The absorption of fertilizer N among treatments was significantly different (p≤0.05). Moreover, to select a preferable fertilizer regime and ensure the practicality of the experimental results, the tobacco was treated by five different fertilizer regimes, and the projection pursuit model was built for the selection. Based on the model calculations, 90 kg hm-2 of fertilizer was appropriate, it would brought both economic and environmental benefits for the tobacco cultivation in Hunan province. Source

Deng B.-J.,Hohai University | Shao X.-H.,Hohai University | Chen L.-H.,Hohai University | Wang W.-N.,Hohai University | And 2 more authors.
Journal of Food, Agriculture and Environment | Year: 2013

The 15N-labeled method was used to study the nitrogen balance in flue-cured tobacco field. The results showed that although the production of flue- cured tobacco was increased with the addition of the nitrogen fertilizer, the utilization rate of nitrogen fertilizer was decreased gradually. Nitrogen was mainly distributed in the stems and leaves of the flue-cured tobacco, and went up gradually with the increase of nitrogen fertilizer. Generally, with the increase of nitrogen fertilizer, the proportion of fertilizer-N in roots, stems, buds and terminal buds first increased and then decreased, however, it basically showed the increasing trend in leaves. The loss of nitrogen (runoff, seepage and sediment) and wastage nitrogen (other ways) mainly came from soil-N with the increase of nitrogen fertilizer rate. The increase of nitrogen fertilizer rate aggravated the loss of nitrogen, increased the surplus of soil nitrogen, and reduced the recycling rate of nitrogen. Considering the yield, quality and nitrogen utilization rate comprehensively, T8 (120 kg/ hm2) showed the best nitrogen fertilizer rate in this experiment. Source

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

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