基于稳定氢氧同位素的黄土高原不同生长年限油用牡丹水分来源研究

Analysis on Sources of Soil Water Absorbed by Oil Peonies of Different Ages Based on Stable Isotopes of Hydrogen and Oxygen Found on Loess Plateau

[目的]探究油用牡丹的水分来源与用水策略,为合理种植、推广发展油用牡丹,提高牡丹成活率提供科学依据.[方法]以不同生长年份的2种油用牡丹为研究材料,利用稳定氢氧同位素探究其在春秋2个季节的水分来源.[结果]①由于根系更加发达,成年期油用牡丹的用水策略比幼年期有更强的自主选择性.春(旱)季,2种年龄油用牡丹都主要利用0-20 cm表层土壤水,但成年期(70.7%)比幼年期(61.8%)对水分的利用率更高.秋(雨)季,表层土壤含水量过高,成年期油用牡丹较幼年期则更趋向吸收深层土壤水分;②通过分析土壤含水率、油用牡丹吸收的不同来源水分的贡献率及它们之间的关系,可知贡献率越高的土层含水量越低.[结论]在黄土高原春秋2个季节,油用牡丹均倾向于吸收含水量较低土层水分,证明了其耐旱不耐涝的特性.

[Objective]The sources and use strategies of soil water absorbed by an oil peony were explored in order to provide a basis for the improvement of the survival rates in rational plantations of the plants and the development of the oil peony industry.[Methods]Two kinds of oil peonies of different ages were used as materials.The ratios of stable hydrogen and oxygen isotopes in the plant and soil water were tested to analyze the sources of soil water absorbed by oil peonies in spring and autumn.[Results]①Mature individuals of oil peonies developed strong root systems and consequently more optimal strategies of water use than young individuals did.In spring(or dry season),oil peonies with two ages mainly absorbed water from surface soil(0—20 cm).However,mature oil peonies used more water(70.7%)from the surface soil than young ones did(61.8%),comparatively.In autumn(or relatively humid season),there was high water content in the surface soil.Mature oil peonies conversely tended to absorb soil water from deeper layers of soil compared with young peonies.②On the basis of the analysis of soil water content,the contribution rates of different sources of soil water to the growth of peonies,and their relationships,it was found that the soil layers with high contribution rates of water to the growth of oil peonies had low soil water content.[Conclusion]An oil peony tends to absorb water from soil layers with low water content during spring and autumn.This verifies both the tolerance of an oil peony to drought and its intolerance to waterlogging.