【作者】 袁仕豪；

【导师】 韩锦峰； 汪耀富；

【作者基本信息】 河南农业大学 ， 作物栽培学与耕作学， 2008， 博士

【摘要】 采用控水盆栽、模拟不同降雨年型灌溉和大田试验研究了水氮互作对烟田土壤供肥特性、烟株养分吸收、烤烟水分和肥料利用率及烟叶产量与品质的影响。主要结果如下:1.烟田土壤氮素矿化形态以硝态氮为主,在烤烟生长前期土壤氮素矿化量较小,中后期矿化量较大。植烟土壤硝态氮和铵态氮浓度受施氮量和土壤水分含量的双重影响,随施氮量和土壤水分含量增加,植烟土壤有效供氮量增大,而且施氮对提高土壤供氮能力的效应大于灌水,二者存在显著的互作效应。施用氮肥后,烟田土壤氮素供应主要集中在0～20cm土层,供氮形态以硝态氮为主,供氮时期主要在烤烟生长的前中期,且施氮量越高,土壤供氮能力越强。2.随氮用量增加,烤烟对氮、磷、钾的吸收量都增大,施氮和灌水对烤烟养分吸收都有显著的促进作用,但氮用量的效应大于灌水的作用,水氮互作可以显著促进烤烟对养分的吸收。烤烟吸收的氮素主要分配在叶片中,以中部叶和上部叶氮素积累量较多,下部叶较少。烤烟不同生育期对土壤氮和肥料氮的吸收比例不同,在大田试验条件下,烤烟生长前中期以吸收肥料氮为主,而成熟期则以吸收土壤氮为主。在盆栽条件下,烤烟各生育期都以吸收肥料氮为主。灌水可以促进烤烟对肥料氮的吸收,水氮互作对烤烟吸收肥料氮有显著的耦合效应。施氮还可以加速土壤有机氮的分解释放,对烤烟吸收土壤氮产生显著的激发效应。3.烤烟不同生育期土壤氮和肥料氮对烟株氮素积累的贡献率不同。在大田条件下成熟期土壤氮对烟株氮素积累的贡献率大于肥料氮,且对上部叶氮素积累的贡献率大于中部叶和下部叶。在盆栽条件下烤烟各生育期肥料氮对烟株体内氮素积累的贡献率都大于土壤氮,且随施氮量和土壤水分含量增加,肥料氮对烤烟根、茎、叶中氮素积累的贡献率逐渐升高,而土壤氮的贡献率逐渐降低。不同部位叶片相比较,肥料氮对下部叶氮素积累的贡献率较大,对上部叶氮素积累的贡献率较小。4.水氮互作可以显著提高烤烟水分利用效率。在大田条件下烤烟的耗水量较大,对水分的利用效率较低。在盆栽条件下烤烟的耗水量较小,水分利用效率较高。在模拟不同降雨年型灌溉试验条件下,平水年和丰水年烤烟水分利用效率较低,欠水年水分利用效率较高。随施氮量增加,烤烟水分利用效率有增大的趋势。施氮和灌水对提高烤烟水分利用率存在显著的互作效应,在土壤水分含量不足的条件下,施氮具有以肥调水的作用,促进烤烟对水分的利用;在施氮量较大的情况下,灌水则有以水促肥的效果,促进烤烟对肥料的吸收。5.采用¹⁵N同位素示踪技术对不同水氮处理烤烟氮肥利用率的研究结果表明,在大田条件下烤烟的氮素利用率较低,而在盆栽条件下的利用率较高。在模拟不同降雨年型灌溉条件下,欠水年烤烟对氮肥的利用率较低,丰水年利用率较高,水氮互作可以显著提高烤烟氮肥利用率。随氮用量增加,大田烤烟氮肥表观利用率呈上升趋势,而氮肥的农艺利用率、生理利用率和氮肥的偏生产力呈下降趋势,烤烟对土壤氮的依赖性逐渐减弱,对肥料氮的依赖性逐渐增强。在施氮量127.5 kg/hm²条件下,烤烟的氮肥利用率只有23.1～31.8%。烟叶采收结束,肥料氮在土壤中的残留量占施氮量的29%以上,氮肥的损失率在35%以上。烟田肥料氮的残留主要集中在0～20 cm土层,随氮用量和灌水量增加,肥料氮向深层土壤中的淋溶量增大。6.在相同施氮量条件下,随追肥比例增大,烤烟对基肥氮的吸收量明显减少,对追肥氮的吸收量显著增加,烟株总吸氮量及其对肥料氮的吸收比例增大,对土壤氮的吸收比例减小。随追肥用量增加,烤烟对基肥氮的利用率升高,对追肥氮的利用率降低,但各生育期不同基肥与追肥比例处理烤烟对追肥的利用率都显著高于基肥,烤烟对氮肥（基肥+追肥）的利用率增大。烟叶采收结束,基肥氮和追肥氮在烟田土壤中都有不同程度的残留,随追肥比例增大,基肥氮的残留量降低,追肥氮的残留量增加,但肥料氮的总残留量和损失量减少。因此,在施氮量一定的条件下,适当增大追肥比例可以提高多雨地区烤烟氮肥利用率。7.随氮用量和土壤含水量增大,烤烟的株高、茎围、平均叶长、平均叶宽和平均单叶面积都有不同程度增加,水氮互作对烤烟生长具有显著的促进作用,而且株高、叶长和叶面积的增长对土壤水分的反应较叶宽和茎围敏感。从不同水氮处理烤烟干物质积累和分配情况看,随氮用量增加,烤烟根、茎、叶中干物质积累量都显著增大,干物质在烟株体内的分配以叶中最高,茎中次之,根中最低;随生育期延伸,干物质在叶中的分配比例有降低的趋势,而在根和茎中的分配比例有增加的趋势。水氮互作对烤烟干物质积累有显著的促进作用,而且施氮对烤烟干物质积累的作用大于灌水,水氮之间存在显著的耦合效应。8.盆栽试验结果表明,施氮对烟叶的增产效应大于灌水,水氮互作可以显著提高烟叶产量。烤烟不同生育期干旱对烟叶产量和品质的影响效应不同,以旺长期干旱对烟叶产量的影响较大,而成熟期干旱对烟叶品质的影响较为显著。大田试验结果表明,在一定范围内随氮用量增加,烟叶产量、产值和上等烟比例都显著增大,烟叶中总糖和还原糖含量下降,烟碱和总氮含量升高。施氮和灌水都可以提高烟叶的产量、产值和上等烟比例,但施氮的效应大于灌水,灌水和施氮量之间存在不同程度的的互作效应。从不同氮用量处理烟叶经济性状、化学成分和评吸质量综合分析,浏阳试点氮用量以127.5 kg/hm²左右较好,湘西试点施氮量以112.5 kg/hm²左右较为适宜。9.根据控水盆栽和模拟不同降雨年型灌溉试验结果,建立了烤烟生长、干物质积累和烟叶产量的水氮互作效应模型。结果表明,在不同施氮水平下,烤烟株高和干物质积累量与土壤水分呈线性相关,单叶面积与土壤水分呈二次曲线相关;在不同土壤水分条件下,烤烟株高、单叶面积和干物质积累量与施氮量均呈二次曲线相关。说明随氮用量和土壤水分含量增大,烟叶产量、产值和上等烟比例增加,但在氮用量和土壤水分含量较高时,水氮的增产效应都趋于降低。根据所建烤烟水氮互作模型分析,充足的水氮供应能促进烤烟生长和干物质积累,提高烟叶产量。更多还原

【Abstract】 Water controlled pot experiment,simulated experiment and field experiments were employed to study the effects of water and nitrogen interaction on nitrogen supply characteristics of tobacco field,nutrients uptake of tobacco plant,water and fertilizer use efficiency,and yield and quality of flue-cured tobacco.The results were as follows:1.The main form of mineralization nitrogen intobacco field was nitrate,and the amount of mineralized nitrogen in early growth stage of flue-cured tobacco was less than that in middle and later stage.The concentration of nitrate and ammonium in tobacco field were affected by nitrogen rate and soil moisture.With the increase of nitrogen rate and soil moisture,the available nitrogen in tobacco field increased.Moreover,the effect of nitrogen rate on improving soil nitrogen supply was greater than that of soil moisture,and significant interaction effects of water and fertilizer coupling were observed.After fertilization,the available nitrogen in tobacco field was mainly centralized in 0～20 cm soil layer depth,the main nitrogen form was nitrate and the main supply stage of nitrogen was at the early and middle growing stage of flue-cured tobacco.The more the nitrogen rate,the greater the nitrogen supply of the soil.2.With the increasing of nitrogen rate,the uptake amount of nitrogen,phosphorus and potassium of flue-cured tobacco increased.Both nitrogen fertilization and irrigation could significantly improve nutrients absorption of tobacco plant,but the effect of nitrogen rate was greater than that of irrigation,and significant interaction effect was found in water and nitrogen coupling.The nitrogen absorbed by tobacco plant was mainly distributed in the leaves,and the accumulation of nitrogen in cutters and upper leaves were more than that of lower leaves.The absorption proportion of soil nitrogen and fertilizer nitrogen changed with the different growth period of flue-cured tobacco.In the condition of field experiment,nitrogen absorbed by tobacco plant was mainly from fertilizers in the early and middle growth stage,and that was mainly from soil nitrogen sources at mature stage.However,in the condition of pot experiment,the nitrogen accumulated in the plant was mainly from fertilizers in all growth period of flue-cured tobacco. Irrigation could promote tobacco plant to absorb nitrogen from fertilizers,and there was significant positive interaction effect between water and nitrogen coupling on uptake of fertilizer nitrogen.The application of nitrogen could speedup the decomposition of soil organic matter, which could produce significant priming effect on flue-cured tobacco to absorb soil nitrogen.3.The contribution rate of soil and fertilizer nitrogen to accumulation of nitrogen in the plant was different at different growth period of flue-cured tobacco.Under field experiment,the contribution rate of soil nitrogen to nitrogen accumulation of tobacco plant was greater than that of fertilizers,especially in the upper leaves in mature stage.Under pot experiment,the contribution rate of fertilizer nitrogen to the accumulation of nitrogen in tobacco plant was greater than that of soil nitrogen in all growth period of flue-cured tobacco,and which was increased with the increase of nitrogen rate and soil moisture,while the contribution rate of soil nitrogen was decreased. Furthermore,the contribution rate of fertilizer nitrogen to lower leaves was greater than that of upper leaves.4.Water and nitrogen interaction could increase water use efficiency of flue-cured tobacco significantly.Compared with pot experiment,water consumption of tobacco plant was more and water use efficiency was lower in field experiment.In the year of different precipitations,water use efficiency of flue-cured tobacco in normal year and the year with high water was lower than that in the year with low water,and it tended to increase with the increasing of nitrogen rate.There was significant effect of interaction between irrigation and nitrogen rate on improving water use efficiency of flue-cured tobacco.Under the condition of low soil moisture,the application of nitrogen could enlarge soil water utilization which showed the effect in raising water use efficiency by increasing fertilization.Under the condition of high nitrogen rate,irrigation could increase the uptake of fertilizers which showed the effect in raising fertilizer use efficiency by irrigation.5.The nitrogen use efficiency of flue-cured tobacco investigated in field experiment was lower than that in pot experiment.In the year of different precipitations,nitrogen use efficiency of tobacco plant in the year with low water was lower than that in the year with high water,and water and nitrogen coupling could increase nitrogen use efficiency significantly.With the increasing of nitrogen rate,the apparent recovery efficiency of nitrogen tended to increase,the agronomic nitrogen efficiency,physiologic nitrogen efficiency and partial factor productivity for applied nitrogen tended to decrease,and the soil nitrogen dependency of flue-cured tobacco reduced,while the fertilizer nitrogen dependency increased.Under the condition of nitrogen rate at 127.5kg/hm~2, the nitrogen use efficiency of flue-cured tobacco was 23.1～31.8%.After harvest of tobacco leaves,the residual ratio of fertilizer nitrogen in the field was more than 29%,and the loss rate was beyond 35%.The residue of fertilizer nitrogen was mainly centralized at 0～20 cm soil layer depth, and the eluviations of fertilizer nitrogen in tobacco field increased with the increasing of nitrogen rate and irrigation.6.Under the same application rate of nitrogen,the nitrogen uptake amount of flue-cured tobacco derived from base fertilizer decreased,and increased significantly from top dressing with the increasing proportion of top dressing.The total nitrogen uptake amount of tobacco plant and the ratio of nitrogen absorbed from fertilizers raised,while the ratio of nitrogen absorbed from soil nitrogen sources reduced.With the increasing proportion of top dressing,the nitrogen use efficiency(NUE) of the plant to base fertilizer increased and that of top dressing decreased significantly.However,the NUE to top dressing was significantly higher than that of base fertilizer in all treatments at different growth period of flue-cured tobacco,which resulted in the NUE(base fertilizer+top dressing) of flue-cured tobacco increased.After harvesting of all the leaves of tobacco plant,both base fertilizer and top dressing remained in the soil of tobacco field in various degrees.With the increment of top dressing,the residual ratio of base fertilizer decreased and that of top dressing increased,whereas the total residual nitrogen and the nitrogen loss rate of fertilizers reduced significantly.So,under the determinate application rate of nitrogen,increasing the proportion of top dressing reasonably could enhance NUE of flue-cured tobacco in rainy regions.7.With the increase of nitrogen rate and soil water content,the plant height,stalk circumference,average length and width of leaves and leaf area increased in different degree. Water and nitrogen coupling could promote the growth and development of flue-cured tobacco significantly,and the responses of plant height,leaf length and leaf area to soil moisture were more sensitive than that of leaf width and stalk circumference.With the increase of nitrogen rate,dry matter accumulation in root,stalk,and leaf of the plant increased significantly,and the distribution ratio of dry matter in the leaf was the highest,stalk took the second place,and root was the lowest. With the growth and development of tobacco plant,dry matter distribution ratio in the leaf tended to decrease,and that in root and stalk tended to increase.Water and nitrogen coupling could significantly promote dry matter accumulation of flue-cured tobacco,and the effect of nitrogen was greater than that of watering.There was significant interaction effect of water and nitrogen on dry matter accumulation of the plant.8.The results of pot experiment showed that the effect of nitrogen fertilization on increase production of flue-cured tobacco was greater than that of irrigation,and water and nitrogen coupling could improve yield of the leaves significantly.The effect of drought at different growth period of flue-cured tobacco on yield and quality of the leaves was different.The effect of drought stress on yield was relatively obvious at vigorous growing stage and that on quality of the leaves was more significant at mature stage.The results of field experiment indicated that yield,output value and ratio of superior leaves of flue-cured tobacco increased significantly,the content of total sugar and reducing sugar in the leaves decreased,and the content of nicotine and total nitrogen increased with the increment of nitrogen in a certain range.Both application of nitrogen and irrigation could improve yield,output value and ratio of high class leaves of flue-cured tobacco, and the effect of nitrogen was greater than that of irrigation,and different degrees of water and nitrogen coupling effects were also observed.On the comprehensive analysis of the economic characteristics,chemical components and smoking quality of flue-cured tobacco with different treatments of nitrogen rate,the appropriate nitrogen rate of flue-cured tobacco in Liuyang and Xiangxi was about 127.5 kg/hm~2 and 112.5 kg/hm~2 respectively.9.Based on the results of pot and simulation experiments,the models of water and fertilizers for growth,dry matter accumulation and yield of flue-cured tobacco were put forward.The results showed that there was a linear correlation between soil moisture and plant height and dry matter accumulation of flue-cured tobacco,whereas a conic correlation was found between soil water content and single leaf area under different nitrogen rate.However,a conic correlation was observed between nitrogen rate and plant height,single leaf area and dry matter accumulation respectively under different soil moisture.In different irrigation conditions,the models of the effect of nitrogen and potassium fertilizer for yield,output value and ratio of high class leaf of flue-cured tobacco were all conic,which indicated that with the increment of soil moisture and rate of nitrogen and potassium,the yield,output value and ratio of superior leaf increased,but the effect of water and fertilizers for increasing the yield of flue-cured tobacco tended to decrease in higher application level of nitrogen and potassium.According to the coupling models of water and nitrogen established in the experiment,sufficient supply of water and nitrogen could promote growth and dry matter accumulation of flue-cured tobacco,which resulted in the increase of the yield.更多还原