摘要
采用水培法研究了NO3--N和高浓度NH4+-N对莴笋生长及其体内营养元素含量的影响。结果表明:1) 生长在用自来水配制的高浓度NH4+-N营养液中的莴笋后期才受到铵胁迫的影响,同时NH4+-N处理下莴笋对介质中原有的少量NO3--N的吸收率均高于NH4+-N;2) 在NH4+-N的供给量高于植株的需氮量时,莴笋吸收的NH4+-N并不随介质中NH4+-N浓度的升高而增加;3)供给NO3--N 增加了植株对磷、钾、铁、锰的累积量,减少了对氮、钙的吸收量。吸氮量下降与光照较弱、气温较低有关,钙累积量下降可能与自来水含有较多的HCO3-有关;4) 莴笋根、茎、叶柄、叶片4个器官中养分含量基本上不受NH4+-N 浓度的影响,但与氮素形态关系密切。
Solution culture experiment was conducted to study the effect of nitrate and high concentration of ammonium on the growth and nutrients content of asparagus lettuce. The results show that:(1) Asparagus lettuce is subject to ammonium toxicity in later stage of growth. Nitrate is taken up in preference to ammonium when nutrient solution contains 0.5mmol/L NO3--N. (2) With an excess of NH4+-N supply over N demand, the absorption of NH4+-N doesn抰 elevate as the NH4+-N apply increases. (3) NO3--N grown plants have a higher accumulation of P, K, Fe and Mn, and a lower accumulation of N, and Ca. The decrease of N uptake may be related to low light intensity and temperature, whereas the decrease of Ca accumulation may be due to more HCO3- in tap water. (4) NH4+ concentration don抰 influence nutrients distribution in different organs of asparagus lettuce, while the N form is closely related to the nutrients distribution.
出处
《甘肃农业大学学报》
CAS
CSCD
2001年第3期259-267,共9页
Journal of Gansu Agricultural University
基金
甘肃省自然科学基金资助项目(编号:ZS991-A21-046-N)
