A two-year field experiment conducted under dryland conditions in semi-humid and drought-prone regions of China aimed to assess the effect of ammonia-oxidizing bacterial on maize water use efficiency and yield.A heter...A two-year field experiment conducted under dryland conditions in semi-humid and drought-prone regions of China aimed to assess the effect of ammonia-oxidizing bacterial on maize water use efficiency and yield.A heterotrophic ammonia-oxidizing bacteria(HAOB)strain S2_8_1 was used.Six treatments were applied:(1)no irrigation+HAOB strain(DI),(2)no irrigation+blank culture medium(DM),(3)no irrigation control(DCK),(4)irrigation+HAOB(WI),(5)irrigation+blank culture medium(WM),and(6)irrigation control(WCK).Results revealed that HAOB treatment increased maize growth,yield,and water use efficiency over controls,regardless of whether the year was wet or dry.This improvement was attributed to the accelerated nitrification in the rhizosphere soil due to HAOB inoculation,which subsequently led to increased levels of leaf cytokinins.Overall,these findings suggest that HAOB inoculation holds promise as a strategy to boost water use efficiency and maize productivity in dryland agriculture.展开更多
水氮措施影响设施土壤氮素的转化及硝化微生物活性,但水氮耦合对设施土壤自养和异养硝化作用差异的影响尚不明确。以连续8年设施水氮耦合田间定位试验土壤为研究对象,控制不同土壤田间持水量(WHC)(40%WHC、60%WHC和80%WHC)进行室内微宇...水氮措施影响设施土壤氮素的转化及硝化微生物活性,但水氮耦合对设施土壤自养和异养硝化作用差异的影响尚不明确。以连续8年设施水氮耦合田间定位试验土壤为研究对象,控制不同土壤田间持水量(WHC)(40%WHC、60%WHC和80%WHC)进行室内微宇宙培养试验,通过添加乙炔抑制剂抑制自养硝化途径,研究水氮耦合对设施土壤自养和异养硝化速率及参与自养硝化的氨氧化微生物的影响,分析氨氧化微生物氨氧化古细菌(AOA)和氨氧化细菌(AOB)对自养硝化作用的贡献。结果表明,水氮耦合下,不同硝化途径NH_(4)^(+)-N、NO_(3)^(-)-N含量以及参与自养硝化的AOA amo A和AOB amo A基因拷贝数均有显著差异。无乙炔培养7 d后,NO_(3)^(-)-N含量显著增加,而NH_(4)^(+)-N含量显著降低,AOA amo A和AOB amo A的基因丰度显著增加。添加乙炔后,NO_(3)^(-)-N、NH_(4)^(+)-N含量基本保持恒定,AOA amo A和AOB amo A基因丰度显著减少。水氮耦合显著影响自养和异养硝化速率,冗余分析(RDA)表明,NH_(4)^(+)-N含量、AOB amo A、NO_(3)^(-)-N-C_(2)H_(2)、AOA amo A可分别解释自养和异养硝化速率变异的68.9%、34.9%、32.8%和24.4%。设施土壤存在自养硝化和异养硝化两种途径,60%~80%WHC各施氮处理均以自养硝化为主,占总硝化速率的65%~86%;仅40%WHC下,氮纯养分量300和525 kg·hm^(-2)处理以异养硝化为主,占总硝化速率的61%~77%。AOB和AOA共同驱动自养硝化,且AOB贡献更大。展开更多
基金supported by the National Natural Science Foundation of China(U1304326)the Natural Science Foundation of Henan Provincial(242300421242)。
文摘A two-year field experiment conducted under dryland conditions in semi-humid and drought-prone regions of China aimed to assess the effect of ammonia-oxidizing bacterial on maize water use efficiency and yield.A heterotrophic ammonia-oxidizing bacteria(HAOB)strain S2_8_1 was used.Six treatments were applied:(1)no irrigation+HAOB strain(DI),(2)no irrigation+blank culture medium(DM),(3)no irrigation control(DCK),(4)irrigation+HAOB(WI),(5)irrigation+blank culture medium(WM),and(6)irrigation control(WCK).Results revealed that HAOB treatment increased maize growth,yield,and water use efficiency over controls,regardless of whether the year was wet or dry.This improvement was attributed to the accelerated nitrification in the rhizosphere soil due to HAOB inoculation,which subsequently led to increased levels of leaf cytokinins.Overall,these findings suggest that HAOB inoculation holds promise as a strategy to boost water use efficiency and maize productivity in dryland agriculture.
文摘水氮措施影响设施土壤氮素的转化及硝化微生物活性,但水氮耦合对设施土壤自养和异养硝化作用差异的影响尚不明确。以连续8年设施水氮耦合田间定位试验土壤为研究对象,控制不同土壤田间持水量(WHC)(40%WHC、60%WHC和80%WHC)进行室内微宇宙培养试验,通过添加乙炔抑制剂抑制自养硝化途径,研究水氮耦合对设施土壤自养和异养硝化速率及参与自养硝化的氨氧化微生物的影响,分析氨氧化微生物氨氧化古细菌(AOA)和氨氧化细菌(AOB)对自养硝化作用的贡献。结果表明,水氮耦合下,不同硝化途径NH_(4)^(+)-N、NO_(3)^(-)-N含量以及参与自养硝化的AOA amo A和AOB amo A基因拷贝数均有显著差异。无乙炔培养7 d后,NO_(3)^(-)-N含量显著增加,而NH_(4)^(+)-N含量显著降低,AOA amo A和AOB amo A的基因丰度显著增加。添加乙炔后,NO_(3)^(-)-N、NH_(4)^(+)-N含量基本保持恒定,AOA amo A和AOB amo A基因丰度显著减少。水氮耦合显著影响自养和异养硝化速率,冗余分析(RDA)表明,NH_(4)^(+)-N含量、AOB amo A、NO_(3)^(-)-N-C_(2)H_(2)、AOA amo A可分别解释自养和异养硝化速率变异的68.9%、34.9%、32.8%和24.4%。设施土壤存在自养硝化和异养硝化两种途径,60%~80%WHC各施氮处理均以自养硝化为主,占总硝化速率的65%~86%;仅40%WHC下,氮纯养分量300和525 kg·hm^(-2)处理以异养硝化为主,占总硝化速率的61%~77%。AOB和AOA共同驱动自养硝化,且AOB贡献更大。
