Waterlogging is one of the major abiotic stresses in agricultural crop production.However,the application of 2-chloro-6-(trichloromethyl)pyridine(nitrapyrin)can effectually mitigate the losses of nitrogen efficiency a...Waterlogging is one of the major abiotic stresses in agricultural crop production.However,the application of 2-chloro-6-(trichloromethyl)pyridine(nitrapyrin)can effectually mitigate the losses of nitrogen efficiency and grain yield of summer maize induced by waterlogging.In order to explore its role to alleviate waterlogging stress on leaf antioxidative system and photosynthetic characteristics of summer maize,a field experiment was executed to research effects of nitrapyrin application on leaf photosynthetic and senescent characteristics of waterlogged summer maize Denghai 605(DH605)and Zhengdan 958(ZD958).Experimental treatments consisted of waterlogging treatment that was applying only urea(WL),waterlogging treatment that was applying urea mixing with nitrapyrin(WL-N),and no waterlogging treatment that was only applying urea(NWL).Results showed that WL significantly decreased leaf area index(LAI),SPAD,photosynthetic rate(Pn),and protective enzyme activities,accelerated leaf aging,eventually led to a remarkable yield reduction by 38 and 42%for DH605 and ZD958,respectively,compared to NWL.However,the application of nitrapyrin was useful for relieving waterlogging damages on leaf photosynthetic ability.LAI,SPAD and Pn of WL-N for DH605 were 10,19 and 12-24%higher,and for ZD958 were 12,23 and 7-25%higher,compared to those of WL,respectively.Moreover,application of nitrapyrin effectually relieved waterlogging losses on antioxidative enzyme activities.Leaf superoxide dismutase(SOD),peroxidase(POD)and catalase(CAT)activities of WL-N were averagely increased by 24,15 and 30%,respectively,while malondialdehyde(MDA)content was averagely decreased by 13%,compared to those of WL.Visibly,nitrapyrin application could improve leaf photosynthetic characteristics and retard leaf aging induced by waterlogging,thereby leading to a yield increase of waterlogged maize.展开更多
为减少土壤N_2O排放,提高作物氮素利用,采用田间试验法研究了不同氮肥用量喷涂一定比例的吡啶(0、180、270、360 kg N·hm^(-2))对夏玉米生育期内土壤N_2O排放和氮素表观损失、籽粒产量及氮素利用的影响.结果表明:不同氮肥用量下喷...为减少土壤N_2O排放,提高作物氮素利用,采用田间试验法研究了不同氮肥用量喷涂一定比例的吡啶(0、180、270、360 kg N·hm^(-2))对夏玉米生育期内土壤N_2O排放和氮素表观损失、籽粒产量及氮素利用的影响.结果表明:不同氮肥用量下喷涂吡啶的土壤N_2O排放主要集中在播种-苗期和拔节-抽雄期,基肥和追肥后均会出现显著的土壤N_2O排放通量高峰.随氮肥用量增加,玉米产量不断增加,但270和360 kg N·hm^(-2)间无显著差异,2种施氮量下的玉米分别净增收5209和5426元·hm^(-2).与不施氮肥比,各施氮处理下的玉米籽粒吸氮量提高幅度为109.6%~134.1%.各处理间的氮肥农学效率和氮肥利用率均以氮肥喷涂吡啶270 kg N·hm^(-2)较大,而土壤氮素表观损失较小.氮肥喷涂吡啶在270 kg N·hm^(-2)时玉米增产增收,氮肥利用效率较高,土壤N_2O排放和氮素表观损失较少,是一种较为合理的氮肥调控施用技术.展开更多
The occurrence of nitri?cation in some acidic forest soils is still a subject of debate.Identi?cation of main nitri?cation pathways in acidic forest soils is still largely unknown.Acidic yellow soil(Oxisol) samples we...The occurrence of nitri?cation in some acidic forest soils is still a subject of debate.Identi?cation of main nitri?cation pathways in acidic forest soils is still largely unknown.Acidic yellow soil(Oxisol) samples were selected to test whether nitri?cation can occur or not in acidic subtropical pine forest ecosystems.Relative contributions of autotrophs and heterotrophs to nitri?cation were studied by adding selective nitri?cation inhibitor nitrapyrin.Soil NH^+_4-N concentrations decreased,but NO^-_3-N concentrations increased signi?cantly for the no-nitrapyrin control during the ?rst week of incubation,indicating that nitri?cation did occur in the acidic subtropical soil.The calculated net nitri?cation rate was 0.49 mg N kg^(-1)d^(-1)for the no-nitrapyrin control during the ?rst week of incubation.Nitrapyrin amendment resulted in a signi?cant reduction of NO^-_3-N concentration.Autotrophic nitri?cation rate averaged0.28 mg N kg^(-1)d^(-1)and the heterotrophic nitri?cation rate was 0.21 mg N kg^(-1)d^(-1)in the ?rst week.Ammonia-oxidizing bacteria(AOB) abundance increased slightly during incubation,but nitrapyrin amendment signi?cantly decreased AOB amo A gene copy numbers by about 80%.However,the ammonia-oxidizing archaea(AOA) abundance showed signi?cant increases only in the last 2weeks of incubation and it was also decreased by nitrapyrin amendment.Our results indicated that nitri?cation did occur in the present acidic subtropical pine forest soil,and autotrophic nitri?cation was the main nitri?cation pathway.Both AOA and AOB were the active biotic agents responsible for autotrophic nitri?cation in the acidic subtropical pine forest soil.展开更多
基金This study was funded by the National Natural Science Foundation of China(31801296),the National Key Research and Development Program of China(2017YFD0300304 and 2018YFD0200604),the earmarked fund for China Agriculture Research System(CARS-02-18),and the Funds of Shandong"Double Tops"Program,China(SYL2017YSTD02).
文摘Waterlogging is one of the major abiotic stresses in agricultural crop production.However,the application of 2-chloro-6-(trichloromethyl)pyridine(nitrapyrin)can effectually mitigate the losses of nitrogen efficiency and grain yield of summer maize induced by waterlogging.In order to explore its role to alleviate waterlogging stress on leaf antioxidative system and photosynthetic characteristics of summer maize,a field experiment was executed to research effects of nitrapyrin application on leaf photosynthetic and senescent characteristics of waterlogged summer maize Denghai 605(DH605)and Zhengdan 958(ZD958).Experimental treatments consisted of waterlogging treatment that was applying only urea(WL),waterlogging treatment that was applying urea mixing with nitrapyrin(WL-N),and no waterlogging treatment that was only applying urea(NWL).Results showed that WL significantly decreased leaf area index(LAI),SPAD,photosynthetic rate(Pn),and protective enzyme activities,accelerated leaf aging,eventually led to a remarkable yield reduction by 38 and 42%for DH605 and ZD958,respectively,compared to NWL.However,the application of nitrapyrin was useful for relieving waterlogging damages on leaf photosynthetic ability.LAI,SPAD and Pn of WL-N for DH605 were 10,19 and 12-24%higher,and for ZD958 were 12,23 and 7-25%higher,compared to those of WL,respectively.Moreover,application of nitrapyrin effectually relieved waterlogging losses on antioxidative enzyme activities.Leaf superoxide dismutase(SOD),peroxidase(POD)and catalase(CAT)activities of WL-N were averagely increased by 24,15 and 30%,respectively,while malondialdehyde(MDA)content was averagely decreased by 13%,compared to those of WL.Visibly,nitrapyrin application could improve leaf photosynthetic characteristics and retard leaf aging induced by waterlogging,thereby leading to a yield increase of waterlogged maize.
基金National Basic Research Program of China(2015CB150502)National Natural Science Foundation of China(31172032)Special Fund for Agro-scientific Research in the Public Interest of China(201003016)
文摘为减少土壤N_2O排放,提高作物氮素利用,采用田间试验法研究了不同氮肥用量喷涂一定比例的吡啶(0、180、270、360 kg N·hm^(-2))对夏玉米生育期内土壤N_2O排放和氮素表观损失、籽粒产量及氮素利用的影响.结果表明:不同氮肥用量下喷涂吡啶的土壤N_2O排放主要集中在播种-苗期和拔节-抽雄期,基肥和追肥后均会出现显著的土壤N_2O排放通量高峰.随氮肥用量增加,玉米产量不断增加,但270和360 kg N·hm^(-2)间无显著差异,2种施氮量下的玉米分别净增收5209和5426元·hm^(-2).与不施氮肥比,各施氮处理下的玉米籽粒吸氮量提高幅度为109.6%~134.1%.各处理间的氮肥农学效率和氮肥利用率均以氮肥喷涂吡啶270 kg N·hm^(-2)较大,而土壤氮素表观损失较小.氮肥喷涂吡啶在270 kg N·hm^(-2)时玉米增产增收,氮肥利用效率较高,土壤N_2O排放和氮素表观损失较少,是一种较为合理的氮肥调控施用技术.
基金financially supported by the National Natural Science Foundation of China(No.41271267)
文摘The occurrence of nitri?cation in some acidic forest soils is still a subject of debate.Identi?cation of main nitri?cation pathways in acidic forest soils is still largely unknown.Acidic yellow soil(Oxisol) samples were selected to test whether nitri?cation can occur or not in acidic subtropical pine forest ecosystems.Relative contributions of autotrophs and heterotrophs to nitri?cation were studied by adding selective nitri?cation inhibitor nitrapyrin.Soil NH^+_4-N concentrations decreased,but NO^-_3-N concentrations increased signi?cantly for the no-nitrapyrin control during the ?rst week of incubation,indicating that nitri?cation did occur in the acidic subtropical soil.The calculated net nitri?cation rate was 0.49 mg N kg^(-1)d^(-1)for the no-nitrapyrin control during the ?rst week of incubation.Nitrapyrin amendment resulted in a signi?cant reduction of NO^-_3-N concentration.Autotrophic nitri?cation rate averaged0.28 mg N kg^(-1)d^(-1)and the heterotrophic nitri?cation rate was 0.21 mg N kg^(-1)d^(-1)in the ?rst week.Ammonia-oxidizing bacteria(AOB) abundance increased slightly during incubation,but nitrapyrin amendment signi?cantly decreased AOB amo A gene copy numbers by about 80%.However,the ammonia-oxidizing archaea(AOA) abundance showed signi?cant increases only in the last 2weeks of incubation and it was also decreased by nitrapyrin amendment.Our results indicated that nitri?cation did occur in the present acidic subtropical pine forest soil,and autotrophic nitri?cation was the main nitri?cation pathway.Both AOA and AOB were the active biotic agents responsible for autotrophic nitri?cation in the acidic subtropical pine forest soil.
基金国家科技支撑计划资助项目(2013BAD11B03)国家重点基础研究发展计划项目(973计划)(2012CB955904)+1 种基金The University of Melbourne Early Career Research Grant Scheme 2014中央级公益性科研院所基本科研业务费专项资助项目
