摘要
选用龙井43、乌牛早、迎霜和浙农139等4个茶树品种,在盆栽条件下研究不同形态比例的无机氮肥对苗高和地径的影响,并通过对茶树硝态氮和铵态氮吸收过程的Michaelis-Menten动力学方程比较,探索氮素形态对茶树吸收氮的影响机制。结果表明,氮素形态对苗高影响极显著,对地径影响较小,NO3--N:NH4+-N为5∶5处理的苗高增量最大,每年达15.45cm,纯铵处理最小,每年仅7.03cm。品种间的苗高增量以乌牛早最大,地径增量以龙井43最小。铵态氮比例增加后,茶树根系对硝态氮吸收的最大速率(Vmax)下降,而亲和力先变强,后变弱;铵态氮Vmax随铵态氮比例的增加快速上升,然后下降,而亲和能力会逐渐变弱,但铵态氮比例较低时,亲和力变化较缓。NO3--N:NH4+-N为5∶5处理时,各品种茶树对硝态氮和铵态氮的Vmax分别在0.24～0.35和0.19～0.30mmol FWg-1d-1之间,根系亲和力(Km)在0.65～0.74和0.63～0.80mmolL-1之间,对氮素的整体吸收生理特征优于其他处理。在盆栽条件下,不同氮素形态处理会使茶树对两种氮素的Vmax和Km均发生改变,表明茶树体内具备对土壤环境养分变化的适应机制。
The ammonium and nitrate nitrogen are the main inorganic nitrogen in crop cultivation, the rational application of chemical N fertilizer and improvement of N use efficiency in tea plant are important for tea cultivation. There was little research on the relationship between inorganic nitrogen form and root absorption properties of perennial woody plants. In this study, four tea plant cultivars （Wuniuzao, Longjing 43, Yingshuang, and Zhenong 139） were selected for a pot experiment, and the influences of different N fertilizers with different ratio of NO3-N ： NHa＋-N on height growth and girth growth of tea were studied. In order to explore the absorption mechanism of different inorganic N forms, Michaelis-Menten equations of different N forms were established and compared. The results showed that the chemical nitrogen form of the fertilizer had a very significant effect on the height growth of the tea, but no significant effect on girth growth. The tea height significantly increased, and the increasing amount reached 15.45 cm per year at 5：5 ofNO3-N ： NH4-N ratio, while at the pure NH4＋-N treatment, the increasing amount was only 7.03. Compared with other tea cultivars, the increasing amount in height of Wuniuzao was the most, and in girth of Longjing 43 was the least. The maximum uptake rate （Vmax） for nitrate nitrogen （NO3-N） absorption decreased when the proportion of ammonium nitrogen （NH4＋-N） increased. The affinity to NO3-N was enhanced gradually, but weakened when the proportion of NHa＋-N was over 50%. The Vmax for NI-L＋-N absorption increased quickly until the proportion of NHa＋-N was over 50%, and then decreased slowly. The affinity to NH4＋-N weakened slowly until the NH4＋-N proportion was over 50%, and quickly when the ammonium proportion was too high. When the NO3- ： NH4＋ was 5：5, the Vmax values for NO3-N and NH4＋-N were 0.24-0.35 and 0.19-0.30 mmol FW g^-1 d^-1, respectively, and the Km values were 0.65-0.74 and 0.63-0.80 mmol L-1, respectively, indicating
出处
《作物学报》
CAS
CSCD
北大核心
2010年第2期327-334,共8页
Acta Agronomica Sinica
基金
国家自然科学基金项目(30872055)
江苏省农业科技攻关项目(BE2005368)资助
关键词
茶树
氮素形态
苗高生长
地径生长
吸收动力学特征
Camellia sinensis L.
Nitrogen form
Seedling height growth
Girth growth
Kinetics of inorganic nitrogen absorption
