不同氮磷比施肥对雷竹笋用林笋末期碳氮磷生态化学计量的影响

Effects of Different Nitrogen and Phosphorus Ratios on Ecological Stoichiometry of Carbon,Nitrogen and Phosphorus at the End of Shoot Growth in Phyllostachys violascens Stand

【目的】探究不同氮磷比施肥对雷竹笋用林笋末期碳氮磷生态化学计量和笋产量的影响,得到适宜雷竹生长和生产的生态化学计量比,为雷竹笋用林经济效益提升提供理论依据。【方法】以雨城区中里镇1~5 a生雷竹笋用林为研究对象,研究不同氮磷比施肥下(NP_(3)=3∶1、NP9=9∶1、NP_(15)=15∶1、NP_(21)=21∶1)雷竹碳氮磷养分变化规律和化学计量特征,通过笋产量和各器官养分、土壤因子间的相互关系揭示不同氮磷比施肥处理的雷竹营养生长规律。【结果】(1)氮磷施肥可以显著影响雷竹各器官的C、N、P含量及化学计量比随着施肥氮磷比例的增大,各器官的全C含量、C∶N和C∶P总体上呈先增后减的趋势,全C和全P含量呈先减后增的趋势,N∶P则逐渐减小。(2)氮磷施肥对各器官间C、N、P含量及化学计量比的大小关系影响较小。(3)氮磷施肥显著提高了雷竹鲜笋产量,笋产量随施肥氮磷比例的增大而呈现先增后稳的趋势,雷竹笋产量与土壤p H、全N含量和碱解氮(AN)含量在显著相关关系。(4)土壤p H与雷竹各器官C∶P均有显著相关关系,土壤AN含量与雷竹各器官养分含量和化学计量均有显著相关关系。【结论】研究表明雷竹林地主要受N限制,不同氮磷比施肥处理对其有一定缓解作用,氮磷施肥显著提高了雷竹鲜笋产量,从经济效益和绿色可持续发展的角度考虑,NP_(15)是较合适的氮磷施肥比例,该处理下各器官生态化学计量比可以指导笋用林生产中施肥比例的选择,枝全C含量和细根全N含量一定程度上可以表征雷竹营养生长情况。

【Objective】The current study aimed to explore the effects of nitrogen and phosphorus fertilizer at different ratios on the ecological stoichiometry of carbon,nitrogen and phosphorus and shoot yield at the end of shoot use of Phyllostachys violascens.The ecostoichiometric ratio suitable for the growth and production of P.violascens was obtained,which provided a theoretical basis for improving the economic benefit of bamboo shoot forest.【Method】Taking 1-5 years old bamboo shoot forest in Zhongli town of Yucheng district as the research object,the changes and stoichiometric characteristics of carbon,nitrogen and phosphorus nutrients of P.violascens under different nitrogen-phosphorus ratios(NP_(3)=3∶1,NP9=9∶1,NP_(15)=15∶1 and NP_(21)=21∶1)were studied.The vegetative growth characteristics of P.violascens under different nitrogen-phosphorus ratios was revealed through the relationship among shoot yield,nutrients of different organs and soil factors.【Result】The main results were as follows:(1)Nitrogen and phosphorus fertilization could significantly affect the contents of C,N,P and corresponding stoichiometric ratio of different P.violascens organs.With the increase of the ratio of nitrogen/phosphorus,the content of total C,C∶N,and C∶P in all organs increased at first and then decreased,while the content of total C and total P decreased at first and then increased,and N∶P decreased gradually.(2)Nitrogen and phosphorus fertilization had little effect on the relationship between C,N,P content and stoichiometric characteristics among organs.(3)Nitrogen and phosphorus fertilization significantly increased the fresh shoot yield of P.violascens,and the shoot yield increased at first and then kept stable with the increase of the ratio of nitrogen and phosphorus.There was a significant correlation between bamboo shoot yield and soil p H,total N and available nitrogen(AN)content.(4)There was a significant correlation between soil p H and CIRP in all organs of P.violascens,and there was a significant correlation between soil AN content and nutrient content and stoichiometry in all organs of P.violascens.【Conclusion】The forest land of P.violascens is mainly restricted by N,which can be alleviated by different N/P ratio fertilization treatments to a certain extent.Nitrogen and phosphorus fertilization significantly increased the fresh shoot yield of P.violascens.Considering both economic benefit and green sustainable development,NP_(15)is a suitable ratio of nitrogen and phosphorus fertilization.The eco-stoichiometric ratio of each organ can guide the selection of fertilization ratio in the production of shoot forest under the NP_(15)treatment,where the total C content in branches and total N content in fine roots is characteristic of the vegetative growth of P.violascens to some extent.