摘要
为探讨土壤养分空间异质性对油松(Pinus tabulaeformis)根系的影响,弄清油松根系获取土壤养分资源的特性,在有机玻璃板制成的栽培容器中,设置3个施肥深度处理(0<h≤20 cm、20 cm<h≤40 cm、40 cm<h≤60 cm),施肥量为1 kg干土施用0.2 g氮(尿素),形成土壤氮养分的空间异质性。将发芽的油松种子播种到栽培容器中培养,测定生物量、根系特性、氮质量分数和单位根长氮养分吸收质量。结果表明:施肥深度0<h≤20 cm,油松株高和根系干质量最高,根系干质量显著高于施肥深度40 cm<h≤60 cm(P<0.05);根系总长度、总表面积和总体积最高,显著高于其他2个施肥深度(P<0.05),而施肥深度40 cm<h≤60 cm的油松根系总长度、总表面积和总体积最低。比较施肥深度对各土层中根系特性的影响,0<土层深度≤20 cm土层中,施肥深度0<h≤20 cm的油松根系干质量显著高于施肥深度40 cm<h≤60 cm(P<0.05);施肥深度0<h≤20 cm和施肥深度20 cm<h≤40 cm的根系长度均显著高于施肥深度40 cm<h≤60 cm(P<0.05);施肥深度40 cm<h≤60 cm的根系直径最粗,显著高于施肥深度20 cm<h≤40cm(P<0.05)。20 cm<土层深度≤40 cm土层中,根系各指标变化趋势与0<土层深度≤20 cm土层一致。施肥深度40 cm<h≤60 cm的根系氮质量分数显著高于施肥深度0<h≤20 cm(P<0.05)。施肥深度40 cm<h≤60 cm的油松单位根长氮养分吸收质量显著高于施肥深度20 cm<h≤40 cm(P<0.05)。因此,油松根系对土壤养分空间异质性具有敏感性,土壤养分丰富区域,根系长度和表面积增加;养分贫瘠区域,单位根长养分吸收质量增加。土壤养分空间异质性改变了油松根系的形态和功能,促进养分吸收。
The effects of the spatial heterogeneity of soil nutrients on the root of Pinus tabulaeformis was conducted to get the characteristics of P.tabulaeformis roots absorbing soil nutrients.Nitrogen fertilizer(urea,0.2 g·kg-1 dry soil)was applied in the different soil layers of the cultivation container,respectively,i.e.,0<h≤20 cm,20 cm<h≤40 cm,and 40 cm<h≤60 cm.The spatial heterogeneity of soil nutrients was formed by fertilization.The sprouted seeds of P.tabulaeformis were sowed into the cultivation container and the biomass,root characteristics,nitrogen content,and nitrogen nutrient absorption per unit root length were tested and analyzed.The plant height and the biomass of P.tabulaeformis in the treatment of 0<h≤20 cm were the highest,and the root dry weight was significantly higher than that of the treatment of 40 cm<h≤60 cm(P<0.05).The total root length,the root surface area,and the root volume in the treatment of 0<h≤20 cm were the highest,and it was the lowest for 40 cm<h≤60 cm,which was significantly higher than those of 20 cm<h≤40 cm and 40 cm<h≤60 cm(P<0.05).The effects of fertilization depth on root characteristics in different soil layer were compared.In 0-20 cm soil layer,the root dry weight of the treatment of 0<h≤20 cm was significantly higher than that of the treatment of 40 cm<h≤60 cm(P<0.05);the root lengths of the treatments of 0<h≤20 cm and 20 cm<h≤40 cm were significantly higher than that of the treatment of 40 cm<h≤60 cm(P<0.05).The root diameter of the treatment of 40 cm<h≤60 cm was the maximum,which was significantly higher than that of the treatment of 20 cm<h≤40 cm(P<0.05).In 20-40 cm soil layer,the change trend of various parameters of root in the treatment of 20 cm<h≤40 cm were consistent with that in the treatment of 0<h≤20 cm.The nitrogen concentration in root of the treatment of 40 cm<h≤60 cm was significantly higher than that of the treatment of 0<h≤20 cm(P<0.05).The absorption of nitrogen per unit root length in the treatment of 40 cm<h≤60 cm was higher than that of the treatment of 20 cm<h≤40 cm(P<0.05).The results showed that P.tabulaeformis root was sensitive to the spatial heterogeneity of soil nutrients.The root length and surface area increased in the nutrient enrichment area.In the nutrient poor area,nutrient uptake per unit root length increased.Soil nutrient spatial heterogeneity changed root morphology and functionof P.tabulaeformis,which promoted nutrient uptake by roots.
作者
李芳
张西西
吴建芝
刘倩
Li Fang;Zhang Xixi;Wu Jianzhi;Liu Qian;Jin Yingshan(Beijing Institute of Landscape Architecture,Beijing 100102,P.R.China)
出处
《东北林业大学学报》
CAS
CSCD
北大核心
2023年第5期79-83,共5页
Journal of Northeast Forestry University
基金
北京市科技计划项目(D171100001817001)
北京市公园管理中心科技项目(ZX2020021)
关键词
油松
根系特性
土壤养分异质性
氮肥
养分吸收
Pinus tabulaeformis
Root characteristic
Soil nutrient heterogeneity
Nitrogen fertilizer
Nutrient absorption
