This experiment examined the fluctuations in nitrogen gas supersaturation throughout the day in three karst springs (upper, side, and lower) at McNenny State Fish Hatchery, rural Spearfish, Lawrence County, South Dako...This experiment examined the fluctuations in nitrogen gas supersaturation throughout the day in three karst springs (upper, side, and lower) at McNenny State Fish Hatchery, rural Spearfish, Lawrence County, South Dakota, USA. Total gas pressures, oxygen percent saturation, and nitrogen percent saturation were recorded six times/day on eight days over a 26-day period in each of the three springs. Total gas pressure did not vary significantly throughout the day in any of the springs. However, percent oxygen and nitrogen saturation were significantly different throughout the day in all three springs. The highest mean (SE) nitrogen supersaturation value of 118.5 (1.1)% was observed in the lower spring at 07:00. The lowest mean nitrogen supersaturation values were 114.5 (1.1)% at 13:00 in the upper spring, and 114.2 (0.2)% and 113.1 (0.7)% at 15:00 in the side and lower spring, respectively. At 118% nitrogen supersaturation, gas bubble disease is likely to occur in fish, resulting in potentially high levels of mortality if untreated spring water was used for fish production. The results of this study indicate the importance of recording nitrogen gas levels at sunrise or early in the morning, when nitrogen is highest and oxygen is lowest, to obtain accurate and reproducible data.展开更多
为应对干旱内陆河流域夏季农业用水供需紧张的矛盾,提高滴灌春玉米水氮利用效率,以滴灌春玉米为研究对象,在新疆奇台县半截沟镇腰站子村进行田间试验,设置3600(W1)、3300(W2)、3000(W3)、2700(W4)、2400 m^(3)·hm^(-2)(W5)5个灌水...为应对干旱内陆河流域夏季农业用水供需紧张的矛盾,提高滴灌春玉米水氮利用效率,以滴灌春玉米为研究对象,在新疆奇台县半截沟镇腰站子村进行田间试验,设置3600(W1)、3300(W2)、3000(W3)、2700(W4)、2400 m^(3)·hm^(-2)(W5)5个灌水水平和461(N1)、428(N2)、394 kg·hm^(-2)(N3)3个施氮水平,探究偏低水氮管理对春玉米产量、水分利用效率(water use efficiency,WUE)和氮肥偏生产力(partial factor productivity from nitrogen fertilizer,PFPN)的影响,并对较低限额灌水施肥方案进行优选。结果表明,玉米株高、茎粗、叶面积指数及地上部干物质量均呈现随灌溉定额的增加而增加、随施氮量增加先增加后减少的趋势,其中W1N2处理表现最优。随着灌溉定额的增加,产量和PFPN呈不断增加的趋势,WUE呈不断降低的趋势;随着施氮量的增加,产量和WUE呈先增加后减少的趋势,PFPN呈不断降低的趋势。W1N2处理的产量最高(19250 kg·hm^(-2)),W5N2处理的WUE最高(4.52 kg·m^(-3)),W1N2处理的PFPN最高(44.77 kg·kgg^(-1))。基于水分利用效率、净利润、产投比等15个指标层构建的层次分析法-熵权法-优劣解距离向量法(analytic hierarchy process-entropy weight method-technique for order preference by similarity to an ieded solution,AHP-EWM-TOPSIS)模型评价结果可知,灌溉定额3000~3600 m^(3)·hm^(-2)、施氮量394~428 kg·hm^(-2)为推荐的低水氮定额管理方案,此时产量达17010~19250 kg·hm^(-2),WUE为3.69~4.14 kg·m^(-3),PFPN为22.89~25.67 kg·kgg^(-1),该方法为作物生长综合效益提供了一种可靠的评价体系。研究结果为干旱区滴灌春玉米水氮配施策略的制定提供模型与数据参考,对实现农业生态经济效益最大化具有重要意义。展开更多
Spring maize is one of the most popular crops planted in northeastem China. The cropping systems involving spring maize have been maintaining high production through intensive management practices. However, the high r...Spring maize is one of the most popular crops planted in northeastem China. The cropping systems involving spring maize have been maintaining high production through intensive management practices. However, the high rates of nitrogen （N） fertilizers application could have introduced a great amount of nitrous oxide （N2O） into the atmosphere. It is crucial for sustaining the maize production systems to reduce N2O emissions meanwhile maintaining the optimum yields by adopting alternative farming management practices. The goal of this study was to evaluate effects of alternative fertilization and crop residue management practices on N2O emission as well as crop yield for a typical maize field in northeastern China. Field experiments were conducted during the 2010-2011 maize growing seasons （from early May to late September） in Liaoning Province, northeastern China. N2O fluxes were measured at the field plots with six different treatments including no N fertilizer use （CK）, farmers＇ conventional N fertilizer application rate （FP）, reduced N fertilizer rate （OPT）, reduced N fertilizer rate combined with crop straw amendment （OPTS）, slow-release N fertilizer （CRF）, and reduced N fertilizer rate combined with nitrification inhibitor （OPT＋DCD）. The static chamber method combined with gas chromatography technique was employed to conduct the measurements of N2O fluxes. The field data showed that N2O emissions varied across the treatments. During the maize growing season in 2010, the total N2O emissions under the treatments of CK, FP, OPT, OPTS, and CRF were 0.63, 1.11, 1.03, 1.26, and 0.98 kg N ha-1, respectively. The seasonal cumulative N2O emissions were 0.54, 1.07, 0.96, 1.12, and 0.84 kg N ha1, respectively, under CK, FP, OPT, OPTS, and OPT＋DCD in 2011. In comparison with FP, CRF or OPT＋DCD reduced the N2O emissions by 12 or 21%, respectively, while the crop yields remained unchanged. The results indicate that the reduction of N-fertilizer application rate in combination with the slow-release fertilizer type or nitrification inhibitor could effectively mitigate N2O emissions from the tested field. The incorporation of crop residue didn＇t show positive effect on mitigating N2O emissions from the tested cropping system. The field study can provide useful information for the on-going debate on alternative N fertilization strategies and crop straw management in China. However, further studies would be needed to explore the long-term impacts of the alternative management practices on a wide range of environmental services.展开更多
Gliadin, the major storage protein in endosperm, affects grain quality in spring wheat by its content and composition. Eighteen cultivars differing in HMW-GS were used in the study to approach the accumulation pattern...Gliadin, the major storage protein in endosperm, affects grain quality in spring wheat by its content and composition. Eighteen cultivars differing in HMW-GS were used in the study to approach the accumulation pattern of gliadin fractions α, β, γ, ω and regulation of three kinds of nitrogen source. The results showed that the content of gliadin in grains increased gradually along with the process of grain-filling, but the accumulation intensity and final content differed evidently among cultivars with different HMW-GS composition. Of all the subunit types used here, cultivars with subunits 7＋9 and 2＋12 had smaller accumulation intensity and lower final content. During grain-filling, 4 gliadin fractions had the same increase trend, but differed in accumulation course. The dynamic trends of gliadin accumulation were similar in different nitrogen treatments whose effects on initial amount, accumulation intensity and final level of accumulation varied with cultivars. Of three nitrogen fertilizer types, the amide-form nitrogen source was better to the formation and accumulation of gliadin as well as its four fractions.展开更多
【目的】探明麦后复种绿肥协同不同水平氮肥对春小麦产量和籽粒品质的影响,对构建青海省基于绿肥的化肥减施与优质生产模式提供理论指导。【方法】于2023—2024年在青海大学农林科学院试验地进行裂区试验,主区为麦后复种绿肥(W-G)和麦...【目的】探明麦后复种绿肥协同不同水平氮肥对春小麦产量和籽粒品质的影响,对构建青海省基于绿肥的化肥减施与优质生产模式提供理论指导。【方法】于2023—2024年在青海大学农林科学院试验地进行裂区试验,主区为麦后复种绿肥(W-G)和麦后休闲(W)2种种植模式;副区为不施氮(N0)、氮肥减施30%(N1,157.5 kg N·hm^(-2))、当地习惯施氮(N2,225 kg N·hm^(-2))3个施氮水平,测定小麦产量及籽粒品质(籽粒蛋白、沉降值、形成时间、稳定时间、湿面筋等)。【结果】2023和2024年,W-GN1处理籽粒产量较WN1分别增加5.5%和13.4%,较WN2处理增加了2.0%和5.3%;W-GN1处理生物产量较WN1分别增加5.1%和10.6%,较WN2处理增加1.5%和4.6%。W-G较W处理能获得较高的收获指数。复种绿肥补偿效应在不施氮水平下呈负值,在施氮水平下为2.0%—14.0%,复种绿肥结合氮肥减施30%对增加作物产量的贡献最佳。同时,W-GN1处理可通过增加籽粒蛋白含量、沉降值、形成时间和稳定时间改善籽粒品质,其籽粒蛋白含量较WN1分别增加10.62%和9.48%;籽粒沉降值分别增加25.05%和18.13%;籽粒形成时间分别增加34.70%和8.66%;籽粒稳定时间分别增加41.30%和13.68%。通过主成分分析可知,麦后复种绿肥对籽粒蛋白含量、沉降值、形成时间和稳定时间的提升更为显著。【结论】麦后复种绿肥协同氮肥减施30%(N1,157.5 kg N·hm^(-2))显著提高了小麦籽粒产量,改善了籽粒品质,可作为青海省减施化肥条件下小麦提质稳产的适宜种植模式和施氮水平。展开更多
文摘This experiment examined the fluctuations in nitrogen gas supersaturation throughout the day in three karst springs (upper, side, and lower) at McNenny State Fish Hatchery, rural Spearfish, Lawrence County, South Dakota, USA. Total gas pressures, oxygen percent saturation, and nitrogen percent saturation were recorded six times/day on eight days over a 26-day period in each of the three springs. Total gas pressure did not vary significantly throughout the day in any of the springs. However, percent oxygen and nitrogen saturation were significantly different throughout the day in all three springs. The highest mean (SE) nitrogen supersaturation value of 118.5 (1.1)% was observed in the lower spring at 07:00. The lowest mean nitrogen supersaturation values were 114.5 (1.1)% at 13:00 in the upper spring, and 114.2 (0.2)% and 113.1 (0.7)% at 15:00 in the side and lower spring, respectively. At 118% nitrogen supersaturation, gas bubble disease is likely to occur in fish, resulting in potentially high levels of mortality if untreated spring water was used for fish production. The results of this study indicate the importance of recording nitrogen gas levels at sunrise or early in the morning, when nitrogen is highest and oxygen is lowest, to obtain accurate and reproducible data.
文摘为应对干旱内陆河流域夏季农业用水供需紧张的矛盾,提高滴灌春玉米水氮利用效率,以滴灌春玉米为研究对象,在新疆奇台县半截沟镇腰站子村进行田间试验,设置3600(W1)、3300(W2)、3000(W3)、2700(W4)、2400 m^(3)·hm^(-2)(W5)5个灌水水平和461(N1)、428(N2)、394 kg·hm^(-2)(N3)3个施氮水平,探究偏低水氮管理对春玉米产量、水分利用效率(water use efficiency,WUE)和氮肥偏生产力(partial factor productivity from nitrogen fertilizer,PFPN)的影响,并对较低限额灌水施肥方案进行优选。结果表明,玉米株高、茎粗、叶面积指数及地上部干物质量均呈现随灌溉定额的增加而增加、随施氮量增加先增加后减少的趋势,其中W1N2处理表现最优。随着灌溉定额的增加,产量和PFPN呈不断增加的趋势,WUE呈不断降低的趋势;随着施氮量的增加,产量和WUE呈先增加后减少的趋势,PFPN呈不断降低的趋势。W1N2处理的产量最高(19250 kg·hm^(-2)),W5N2处理的WUE最高(4.52 kg·m^(-3)),W1N2处理的PFPN最高(44.77 kg·kgg^(-1))。基于水分利用效率、净利润、产投比等15个指标层构建的层次分析法-熵权法-优劣解距离向量法(analytic hierarchy process-entropy weight method-technique for order preference by similarity to an ieded solution,AHP-EWM-TOPSIS)模型评价结果可知,灌溉定额3000~3600 m^(3)·hm^(-2)、施氮量394~428 kg·hm^(-2)为推荐的低水氮定额管理方案,此时产量达17010~19250 kg·hm^(-2),WUE为3.69~4.14 kg·m^(-3),PFPN为22.89~25.67 kg·kgg^(-1),该方法为作物生长综合效益提供了一种可靠的评价体系。研究结果为干旱区滴灌春玉米水氮配施策略的制定提供模型与数据参考,对实现农业生态经济效益最大化具有重要意义。
基金the National Natural Science Foundation of China(31270486)the Special Fund for Agriculture Scientific Non-Profit Research of China(201103039)+1 种基金the National Basic Research Program of China(2012CB417104)the National Nonprofit Institute Research Grant of Chinese Academy of Agricultural Sciences(IARRP-2014-402-15)
文摘Spring maize is one of the most popular crops planted in northeastem China. The cropping systems involving spring maize have been maintaining high production through intensive management practices. However, the high rates of nitrogen （N） fertilizers application could have introduced a great amount of nitrous oxide （N2O） into the atmosphere. It is crucial for sustaining the maize production systems to reduce N2O emissions meanwhile maintaining the optimum yields by adopting alternative farming management practices. The goal of this study was to evaluate effects of alternative fertilization and crop residue management practices on N2O emission as well as crop yield for a typical maize field in northeastern China. Field experiments were conducted during the 2010-2011 maize growing seasons （from early May to late September） in Liaoning Province, northeastern China. N2O fluxes were measured at the field plots with six different treatments including no N fertilizer use （CK）, farmers＇ conventional N fertilizer application rate （FP）, reduced N fertilizer rate （OPT）, reduced N fertilizer rate combined with crop straw amendment （OPTS）, slow-release N fertilizer （CRF）, and reduced N fertilizer rate combined with nitrification inhibitor （OPT＋DCD）. The static chamber method combined with gas chromatography technique was employed to conduct the measurements of N2O fluxes. The field data showed that N2O emissions varied across the treatments. During the maize growing season in 2010, the total N2O emissions under the treatments of CK, FP, OPT, OPTS, and CRF were 0.63, 1.11, 1.03, 1.26, and 0.98 kg N ha-1, respectively. The seasonal cumulative N2O emissions were 0.54, 1.07, 0.96, 1.12, and 0.84 kg N ha1, respectively, under CK, FP, OPT, OPTS, and OPT＋DCD in 2011. In comparison with FP, CRF or OPT＋DCD reduced the N2O emissions by 12 or 21%, respectively, while the crop yields remained unchanged. The results indicate that the reduction of N-fertilizer application rate in combination with the slow-release fertilizer type or nitrification inhibitor could effectively mitigate N2O emissions from the tested field. The incorporation of crop residue didn＇t show positive effect on mitigating N2O emissions from the tested cropping system. The field study can provide useful information for the on-going debate on alternative N fertilization strategies and crop straw management in China. However, further studies would be needed to explore the long-term impacts of the alternative management practices on a wide range of environmental services.
文摘Gliadin, the major storage protein in endosperm, affects grain quality in spring wheat by its content and composition. Eighteen cultivars differing in HMW-GS were used in the study to approach the accumulation pattern of gliadin fractions α, β, γ, ω and regulation of three kinds of nitrogen source. The results showed that the content of gliadin in grains increased gradually along with the process of grain-filling, but the accumulation intensity and final content differed evidently among cultivars with different HMW-GS composition. Of all the subunit types used here, cultivars with subunits 7＋9 and 2＋12 had smaller accumulation intensity and lower final content. During grain-filling, 4 gliadin fractions had the same increase trend, but differed in accumulation course. The dynamic trends of gliadin accumulation were similar in different nitrogen treatments whose effects on initial amount, accumulation intensity and final level of accumulation varied with cultivars. Of three nitrogen fertilizer types, the amide-form nitrogen source was better to the formation and accumulation of gliadin as well as its four fractions.
文摘【目的】探明麦后复种绿肥协同不同水平氮肥对春小麦产量和籽粒品质的影响,对构建青海省基于绿肥的化肥减施与优质生产模式提供理论指导。【方法】于2023—2024年在青海大学农林科学院试验地进行裂区试验,主区为麦后复种绿肥(W-G)和麦后休闲(W)2种种植模式;副区为不施氮(N0)、氮肥减施30%(N1,157.5 kg N·hm^(-2))、当地习惯施氮(N2,225 kg N·hm^(-2))3个施氮水平,测定小麦产量及籽粒品质(籽粒蛋白、沉降值、形成时间、稳定时间、湿面筋等)。【结果】2023和2024年,W-GN1处理籽粒产量较WN1分别增加5.5%和13.4%,较WN2处理增加了2.0%和5.3%;W-GN1处理生物产量较WN1分别增加5.1%和10.6%,较WN2处理增加1.5%和4.6%。W-G较W处理能获得较高的收获指数。复种绿肥补偿效应在不施氮水平下呈负值,在施氮水平下为2.0%—14.0%,复种绿肥结合氮肥减施30%对增加作物产量的贡献最佳。同时,W-GN1处理可通过增加籽粒蛋白含量、沉降值、形成时间和稳定时间改善籽粒品质,其籽粒蛋白含量较WN1分别增加10.62%和9.48%;籽粒沉降值分别增加25.05%和18.13%;籽粒形成时间分别增加34.70%和8.66%;籽粒稳定时间分别增加41.30%和13.68%。通过主成分分析可知,麦后复种绿肥对籽粒蛋白含量、沉降值、形成时间和稳定时间的提升更为显著。【结论】麦后复种绿肥协同氮肥减施30%(N1,157.5 kg N·hm^(-2))显著提高了小麦籽粒产量,改善了籽粒品质,可作为青海省减施化肥条件下小麦提质稳产的适宜种植模式和施氮水平。
