| 摘要: |
| 【目的】研究盐碱胁迫下施加生物炭和减少氮肥用量对甜菜光合特性的影响，为甜菜抗盐碱栽培及其生理研究提供理论依据。【方法】采用桶栽试验，共设7个处理，其中3个正常施肥处理(各施纯N 180 kg/hm2)，分别为黑钙土处理(CK)、盐碱胁迫处理(ALK)及盐碱胁迫下施加3%生物炭处理(N180)；4个盐碱胁迫下施加3%生物炭并减少氮肥用量处理，施肥量分别为162 kg/hm2 (N162)、144 kg/hm2 (N144)、126 kg/hm2 (N126)、108 kg/hm2 (N108)，在甜菜6叶期开始取样，随后每隔20 d取样1次，共取样5次，分析盐碱胁迫下施加生物炭与减少氮肥用量对甜菜叶绿素含量、RuBP羧化酶活性、净光合速率、气孔导度、叶绿素荧光参数和干物质量的影响。【结果】盐碱胁迫处理显著抑制了甜菜的光合作用和干物质累积，施加3%生物炭能显著缓解盐碱胁迫对甜菜的影响。N162处理甜菜叶绿素含量较ALK处理高36.9%，N180处理甜菜RuBP羧化酶活性较ALK处理提高16.6%。盐碱胁迫下施加生物炭处理中，甜菜净光合速率、气孔导度、光系统Ⅱ最大光能转换效率 (Fv/Fm)、光系统Ⅱ实际光能转换效率(Y(Ⅱ))、光系统Ⅱ相对电子传递速率(ETR)、光化学淬灭系数(qL)、叶片干质量均以N180处理下最大，且随氮肥施用量的减少逐渐减低，但N162处理甜菜的RuBP羧化酶活性、净光合速率、Fv/Fm和Y(Ⅱ)与N180处理相比差异不显著。【结论】结合试验结果和生产成本认为，在盐碱胁迫条件下施加3%生物炭和162 kg/hm2氮肥能有效提高甜菜的光合作用。 |
| 关键词: 甜菜 盐碱胁迫 生物炭 氮肥 光合特性 |
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| 基金项目:国家自然科学基金项目（31671622）；国家糖料现代农业产业技术体系项目（CARS-170201） |
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| Effects of biochar and reduced nitrogen application on photosynthetic characteristics of sugar beet under saline-alkali stress |
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LIU Xinyu,WU Peiran,LI Caifeng,et al
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| Abstract: |
| 【Objective】This study investigated the effects of biochar and reduced nitrogen application on photosynthetic characteristics of sugar beet under saline-alkali stress to provide basis for saline-alkali resistant cultivation and physiological research of sugar beet.【Method】A total of seven treatments were set up in the bucket planting experiment,among which three were normal fertilization treatments of normal chernozem soil (CK),saline alkali stress treatment (ALK) and 3% biochar normal fertilization under saline-alkali stress (N180).In addition,under saline-alkali stress the 3% biochar and reduced nitrogen application with fertilizer rates of 162,144,126 and 108 kg/hm2 were applied to treatments N162,N144,N126 and N108,respectively.Samples were taken at the beginning of the six-leaf period,and every twenty days for a total of five times in the growth period.Then,the effects of biochar and nitrogen fertilizer application on chlorophyll content,RuBP carboxylase activity,net photosynthetic rate,stomatal conductance,chlorophyll fluorescence parameters and dry matter of sugar beet under saline-alkali stress were analyzed.【Result】Saline-alkali stress significantly reduced photosynthesis and dry matter accumulation of sugar beet.The effect of saline-alkali stress on sugar beet was alleviated significantly by applying 3% biochar.Compared with the treatment of ALK,the chlorophyll content in N162 treatment increased by 36.9%,and the RuBP carboxylase activity in N180 treatment increased by 16.6%.The net photosynthetic rate,stomatal conductance,PSⅡ maximum light energy conversion efficiency (Fv/Fm),PSⅡ actual light energy conversion efficiency (Y(Ⅱ)),PSⅡ relative electron transfer rate (ETR),photochemical quenching coefficient (qL) and dry weight of leaves reached the maximum values under N180 treatment and decreased gradually with the decrease of nitrogen fertilizer application rate under five saline alkali stress treatments.There was no significant difference in RuBP carboxylase activity,net photosynthetic rate,Fv/Fm and Y(Ⅱ) between treatments N162 and N180.【Conclusion】Combined with experimental results and production cost,the application of 3% biochar and 162 kg/hm2 nitrogen fertilizer under saline alkali stress could improve effectively the photosynthesis of sugar beet. |
| Key words: sugar beet saline-alkali stress biochar nitrogen fertilizer photosynthetic characteristics |
