作 者：
徐子先;秦璐;李银水;韩配配;廖祥生;胡小加;谢立华;余常兵;张秀荣;廖星
单 位：
中国农业科学院油料作物研究所/农业部油料作物生物学与遗传育种重点实验室
关键词：
芝麻(Sesamum indicum L.);铵硝配比;生物量;根系形态;养分吸收
摘 要：
为了解芝麻苗期生长对氮素形态和配比的要求,明确芝麻氮肥施用适宜的铵硝比,以长江流域主栽芝麻品种中芝13和黄淮流域主栽芝麻品种漯12为材料,采用室外营养液培养方式,根据铵态氮(NH_4~+-N)和硝态氮(NO_3~--N)摩尔浓度比例的不同设置7个处理(10∶0、9∶1、3∶1、1∶1、1∶3、1∶9、0∶10),定期测定和分析营养液p H值、植株生物量、根系形态参数、地上部和根部养分(N、P、K、Ca、Mg)浓度、游离NH_4~+-N和NO_3~--N浓度等。结果表明:高比例NH_4~+-N处理(10∶0、9∶1和3∶1)显著抑制了芝麻苗期生长,主要表现为植株矮小、叶片枯焦、根系粗短,甚至死亡,随着NH_4~+-N比例的增加,抑制程度越明显。两个芝麻品种对NH_4~+毒害的耐受能力不同,中芝13更耐受NH_4~+毒害。铵硝配比1∶9时,两个芝麻品种植株生物量达到最大值,根系最为发达,根际p H值维持在适宜的范围内;其中,中芝13整株干重、总根长和根系总表面积较完全NO_3~--N处理(0∶10)分别显著增加了47%、29%和15%,植株地上部和根系N、P、K浓度较完全NO_3~--N处理分别增加了5%、17%、9%和10%、32%、13%;铵硝配比1∶9对漯12的生物量及养分吸收利用与完全NO_3~--N处理相比没有显著差异。因此,适当加入铵态氮可以提高芝麻苗期生物量,促进根系的生长,铵硝比为1∶9较适合芝麻幼苗的生长及养分的吸收。在芝麻田间氮素施肥中,建议以NO_3~--N为主,同时根据芝麻品种特性及土壤供氮等条件合理配施NH_4~+-N。
译 名：
Effects of different nitrogen form and ratio on growth and nutrient uptake of different sesame cultivars
作 者：
XU Zi-xian;QIN Lu;LI Yin-shui;HAN Pei-pei;LIAO Xiang-sheng;HU Xiao-jia;XIE Li-hua;YU Chang-bing;ZHANG Xiu-rong;LIAO Xing;Oil Crops Research Institute of the Chinese Academy of Agricultural Sciences/Key Laboratory of Biology and Genetic Improvement of Oil Crops,Ministry of Agriculture;
关键词：
sesame(Sesamum indicum L.);;ammonium/nitrate ratio(NH4+-N/NO3--N ratio);;biomass;;root morphology;;nutrient uptake
摘 要：
To explore the effects of nitrogen form and ammonium/nitrate ratio( NH_4~+-N/NO_3~--N ratio) on growth and nutrient uptake of sesame seedlings,2 sesame cultivars Zhongzhi 13 and Luo 12 were employed in hydroponics with 7 NH_4~+-N/NO_3~--N ratio treatments( 10∶ 0,9∶ 1,3∶ 1,1∶ 1,1∶ 3,1∶ 9,0∶ 10). p H values of nutrient solution and plant phenotype were regularly measured. Plant biomass,root morphological parameters,and N,P,K,Ca,Mg,free NH_4~+-N and NO_3~--N concentration of leaf and root were determined at the 28 th day treatments. Results showed that high NH_4~+/NO_3~-ratios( 10 ∶ 0,9 ∶ 1,3 ∶ 1) inhibited seedling growth with dwarf plants,scorched leaves and stubby roots,and the inhibition increased with NH_4~+-N. Cultivar Zhongzhi 13 showed more tolerance to NH_4~+toxicity. Under NH_4~+-N/NO_3~--N ratio at 1∶ 9,seedlings exhibited the greatest plant biomass,and p H of nutrient solution maintained suitable especially for Zhongzhi 13. Compared with total NO_3~--N treatment( 0∶ 10),plant dry weigh,total root length and root surface area of Zhongzhi 13 were significantly increased 47%,29% and 15% respectively. Moreover,appropriate NH_4~+-N/NO_3~--N ratio promoted the absorption and utilization of N,P,K in Zhongzhi 13,as indicated by N,P,K concentrations increase in leaves and roots respectively. However,compared with total NO_3~--N treatments( 0∶ 10),ratio 1∶ 9 was appropriate with no significant effect on plant biomass and nutrients uptake of Luo 12. Therefore,appropriate NH_4~+-N could enhance sesame seedlings biomass and root growth,NH_4~+-N/NO_3~--N ratio of 1∶ 9 was more suitable for growth and nutrient uptake of the seedling. It was recommended that NO_3~--N could be used as a major N source for sesame,and suitable NH_4~+-N for specific sesame cultivars and soil was suggested in field.
