氮素不同用量对核桃幼苗生长及光合特性的影响  

Effects of Different Application Rates of Nitrogen on Walnut Seedling Growth and Photosynthetic Characteristics

作　　者：苗庆选 怀婷婷 刘春晓[1] 马海林[2] 李海云 司东霞[1] Miao Qingxuan;Huai Tingting;Liu Chunxiao;Ma Hailin;Li Haiyun;Si Dongxia(College of Agronomy and Agricultural Engineering,Liaocheng University,Liaocheng 252059,China;Institute of Resources and Environment,Shandong Academy of Forestry,Jinan 250014,China)

机构地区：[1]聊城大学农学与农业工程学院,山东聊城252059 [2]山东省林业科学研究院资源与环境研究所,山东济南250014

出　　处：《山东农业科学》2023年第1期106-111,共6页Shandong Agricultural Sciences

基　　金：山东省林业科技创新项目(LYCX08-2018-43);济南市十大农业特色产业科技创新项目“南山核桃优质安全高效生产关键技术集成与示范”。

摘　　要：为明确氮肥施用对核桃幼苗生长的影响,确定适宜的氮肥用量,本研究采用盆栽试验法,设置5个氮素(N)水平(0、75、150、225、300 mg/kg),研究不同氮素用量对核桃幼苗生长和光合特性的影响。结果表明,施氮量显著影响移栽后90 d核桃幼苗干物质累积量,植株地上部和地下部干物质积累量均随氮素用量的增加呈先升后降的变化趋势。不同生长阶段各氮素处理根长差异显著,移栽初期(45 d),适量氮素供应(150 mg/kg)可促进根系生长,移栽后135 d,不施氮处理根长最大,过量施氮(≥225 mg/kg)抑制根系生长,总根长降低。施氮显著影响核桃幼苗功能叶片的光合特性和氮素吸收,叶片的蒸腾速率、净光合速率、气孔导度、胞间CO_(2)浓度和氮素吸收量均在氮素用量150 mg/kg时达到最大。由地上部干物质积累量与氮素用量的拟合方程得出,本试验条件下核桃幼苗适宜施氮量为6.5~157.5 mg/kg。In order to clarify the effects of nitrogen(N) application on growth of walnut seedlings and determine appropriate N application rate, five N levels(0, 75, 150, 225, and 300 mg/kg) were set to study their effects on the growth and photosynthetic characteristics of walnut seedlings through pot experiment method. The results showed that N application significantly affected the dry matter accumulation of walnut seedlings at 90 days after transplanting, and the dry matter accumulation in both above-ground and underground parts of the plants increased first and then decreased with the increase of N application rate. There were significant differences in root length between N treatments at different growth stages. At the early stage of transplanting, appropriate amount of N supply(150 mg/kg) could promote root growth, however, after 135 days of transplanting, the control treatment had the maximum root length. Excessive N application(≥225 mg/kg) inhibited root growth and reduced root length. Nitrogen application significantly affected the photosynthetic characteristics and N absorption of functional leaves of walnut seedlings. All the transpiration rate, net photosynthetic rate, stomatal conductance, intercellular CO_(2)concentration and N absorption of leaves reached the maximum when N rate was 150 mg/kg. According to the fitting equation of above-ground dry matter accumulation and nitrogen rate, the optimum N application rate for walnut seedlings under these experiment conditions was 6.5~157.5 mg/kg.

关 键 词：氮素 核桃幼苗 地上部 根系 干物质积累量 光合特性 

分 类 号：S664.106[农业科学—果树学]