| 摘要: |
| 【目的】研究干旱胁迫和施肥对巨能草生物量及C、N、P积累与分配的影响，为巨能草栽培中的水肥管理提供理论依据。【方法】以巨能草为研究对象，采用盆栽试验，利用控水、控肥的试验方法，设计干旱（田间持水量的25%）和正常水分（田间持水量的75%）2个水分梯度以及低肥（复合肥施肥量为2 g/盆）、中肥（复合肥施肥量为4 g/盆）、高肥（复合肥施肥量为8 g/盆）3个养分水平，进行完全随机组合试验，共计6个处理，研究不同处理下巨能草生物量及其分配比例，C、N、P积累与分配特征，N、P吸收和利用效率，以及C∶N、C∶P、N∶P的变化。【结果】在正常水分条件下，随着施肥量的增加，巨能草的地上、地下生物量和总生物量都显著增加；干旱胁迫后，巨能草地上和地下生物量的积累显著降低，施肥对巨能草的地上、地下生物量和总生物量也有显著影响。在正常水分条件下，施肥对巨能草地上和地下生物量的分配比例没有显著影响；在干旱条件下，除低肥处理外，中施肥量和高施肥量均能显著提高巨能草地下生物量的分配比例。施肥和干旱胁迫处理对C、N、P积累量及分配比例也有一定的影响，与正常水分条件相比，干旱胁迫后巨能草的C、N、P积累总量均降低。在正常水分条件下，尽管低肥处理的N、P吸收效率显著低于中、高肥处理，但其N、P利用效率却显著高于中、高肥处理；干旱条件下，不同施肥处理的N、P吸收效率和P利用效率并无显著差异，但N的利用效率随着施肥量的增加而降低。正常水分条件下，施肥处理对地上部分的C∶P、N∶P无显著影响，但高肥处理显著降低了地下部分的N∶P，中、高肥处理显著降低了地上部分的C∶N和地下部分的 C∶P；干旱条件下，施肥处理对地上和地下部分的C∶P及N∶P的影响都不显著，但高肥处理显著降低了地上和地下部分的C∶N。【结论】干旱胁迫处理减少了巨能草的生物量及其对C、N、P的积累，影响了C、N、P的分配，施肥在一定程度上降低了干旱胁迫对植物生长的影响，在巨能草的施肥管理中，应更多地注重对N素的管理。 |
| 关键词: 干旱胁迫 施肥 巨能草 生物量 养分积累和分配 |
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| 基金项目:国家科技支撑计划项目“长江上游低山丘陵区生态综合整治技术及示范”(2011BAC09B05) |
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| Effect of drought stress and fertilization on accumulation and partitioning of biomass,C,N and P of Puelia sinese Roxb |
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ZHANG Mingjin,CHEN Lianghua,ZHANG Jian,et al
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| Abstract: |
| 【Objective】A controlled pot-culture experiment was conducted to investigate effects of drought stress and fertilization on accumulation and partitioning of biomass,C,N and P of Puelia sinese Roxb.【Method】The experiment was a completely randomized design with 6 factorial combinations of 2 moisture gradients (drought,25% field capacity and control,75% field capacity) and 3 levels of fertilization (low,2 g/pot;moderate,4 g/pot;and high,8 g/pot).【Result】Under controlled condition,with the increase of fertilization amount,the below-ground biomass,above-ground biomass and total biomass of Puelia sinese Roxb increased significantly.Under drought stress,the below-ground biomass and above-ground biomass of Puelia sinese Roxb decreased significantly,indicating that fertilization had significantly positive effect on the below-ground biomass,above-ground biomass and total biomass.Under controlled condition,the effects of fertilization on the allocation proportion of the below ground and above-ground biomass were not significant.Under drought stress,both moderate and high fertilizations could significantly improve the allocation proportion of the below-ground biomass,except for low fertilization.Fertilization and drought stress also had certain influences on the accumulation and distribution of C,N and P.Compared with controlled condition,the accumulation quantities of C,N and P decreased after drought stress.Under controlled condition,the absorption efficiencies of N and P under low fertilization treatment were lower than moderate and high fertilizations,while the use efficiencies of N and P were higher under low fertilization treatment than moderate and high fertilizations.Under drought stress,the absorption efficiencies of N and P and the use efficiency of P among different fertilization treatments had no significant difference,but the use efficiency of N decreased with the increase of fertilization amount. Under controlled condition,fertilization had no significant effect on the C∶P and N∶P of above-ground part,but high fertilization significantly reduced the N∶P of underground part,while medium and high fertilizations significantly reduced the C∶N of above-ground part and the C∶P of underground part.Under drought stress,fertilization had no significant effect on the C∶P and N∶P of above-ground and underground part,but high fertilization significantly reduced the C∶N of above-ground and underground part.【Conclusion】Drought stress decreased biomass,C,N and P accumulation,and affected the allocation of biomass,C,N and P.Fertilization could mitigate the effects of drought stress on plant growth and maintain a higher accumulation of biomass,C,N and P.More attention should be paid to the N fertilization management of Puelia sinese Roxb. |
| Key words: drought stress fertilization Puelia sinese Roxb biomass nutrient accumulation and partitioning |
