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基于高光谱“玉米田养鹅”模式下作物冠层氮素反演 预览
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作者 冯江 陆治冶 +3 位作者 马昕宇 陈双龙 赵庆贺 王树文 《农机化研究》 北大核心 2020年第3期5-11,共7页
为实现'玉米田养鹅'模式下作物氮素养分快速无损监测,开展了基于高光谱'农牧一体化'实验。以放牧前后的玉米冠层作为研究对象,利用高光谱技术分析不同时期玉米冠层叶片光谱,采用波段自相关分析(Bands Inter-correlation... 为实现'玉米田养鹅'模式下作物氮素养分快速无损监测,开展了基于高光谱'农牧一体化'实验。以放牧前后的玉米冠层作为研究对象,利用高光谱技术分析不同时期玉米冠层叶片光谱,采用波段自相关分析(Bands Inter-correlation Analysis, BICA)与主成分分析(Principal Components Analysis, PCA)相结合的方法提取特征波段,并构建多种光谱参数,进而建立了基于BICA-PCA方法的多元回归模型(Multivariable Regression Model,MRA),并筛选和验证了所建模型。结果表明:随着不同生育期的进行,鹅的粪便会作为肥料给作物补充氮素,近红外光谱反射率增高,红边位置向左移动。建立模型在放牧前期校正集决定系数R_C~2为0.796,校正集均方根误差(Root-mean-square Error Correction, RMSEC)为0.133;在预测集决定系数R_p~2为0.840,预测集均方根误差(Root-mean-square Error Prediction, RMSEP)为0.147。放牧后期R_C~2为0.761,RMSEC为0.094;R_p~2为0.789,RMSEP为0.141。研究结果可为'农牧一体化'优化生产管理和建立氮素养分特征平衡模型提供支持和帮助。 展开更多
关键词 高光谱 农牧一体化 氮素 玉米冠层
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不同氮效率花生品种氮素累积与利用特征 预览
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作者 王春晓 凌飞 +8 位作者 鹿泽启 姜蔚 臧宏伟 张伟 姚杰 兰丰 柳璇 王志新 郑永美 《中国生态农业学报(中英文)》 CAS CSCD 北大核心 2019年第11期1706-1713,共8页
氮是花生(Arachis hypogaea)生长发育必需的大量元素之一,明确不同品种氮素利用特点,可为花生氮高效品种筛选、培育及节氮栽培提供依据。桶栽条件下,利用15N示踪技术,测定了19个花生品种产量、植株氮含量、氮素积累量及3种氮源供氮量等... 氮是花生(Arachis hypogaea)生长发育必需的大量元素之一,明确不同品种氮素利用特点,可为花生氮高效品种筛选、培育及节氮栽培提供依据。桶栽条件下,利用15N示踪技术,测定了19个花生品种产量、植株氮含量、氮素积累量及3种氮源供氮量等指标,并以供试品种的产量及氮效率平均值为基准,将品种划分为高产氮高效、高产氮低效、低产氮高效和低产氮低效4种类型,分析了4种类型品种氮素累积与利用特征。结果表明:1)不同类型花生品种氮效率存在较大差异,氮高效型品种荚果氮效率平均为25.0 kg·kg^-1,比氮低效型品种平均值高13.6%。2)营养体氮含量中等的品种有利于产量和氮效率同时提高,生殖体和整株氮含量不同类型品种间差异不大;在植株有足够氮积累的前提下,提高氮向生殖体的分配比例是高产氮高效品种的基本特征。3)不同类型花生品种土壤氮和肥料氮供氮水平与氮效率一致,根瘤供氮水平与氮效率因品种产量水平而异;当氮效率相近时,根瘤供氮水平高,有利于产量形成;氮高效型土壤供氮比例略高于低效型,根瘤供氮比例与土壤供氮比例相反,土壤氮与根瘤氮有较好的补偿效应;不同类型品种肥料供氮比例相差不大。4)不同类型品种产量和氮效率与氮肥利用率和氮肥偏生产力高度一致,而不同类型品种间氮素生物效率差异较小。综上,不同类型花生品种产量和氮效率存在显著差异,选育产量和氮效率双高的品种不仅必要,而且可行,是未来花生节氮栽培的有效途径之一。 展开更多
关键词 花生 氮素 品种类型 产量 氮效率 氮累积与利用
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Determination of critical nitrogen dilution curve based on leaf area index for winter wheat in the Guanzhong Plain, Northwest China 预览
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作者 QIANG Sheng-cai ZHANG Fu-cang +3 位作者 Miles Dyck ZHANG Yan XIANG You-zhen FAN Jun-liang 《农业科学学报:英文版》 SCIE CAS CSCD 2019年第10期2369-2380,共12页
Excessive use of nitrogen (N) fertilizers in agricultural systems increases the cost of production and risk of environmental pollution. Therefore, determination of optimum N requirements for plant growth is necessary.... Excessive use of nitrogen (N) fertilizers in agricultural systems increases the cost of production and risk of environmental pollution. Therefore, determination of optimum N requirements for plant growth is necessary. Previous studies mostly established critical N dilution curves based on aboveground dry matter (DM) or leaf dry matter (LDM) and stem dry matter (SDM), to diagnose the N nutrition status of the whole plant. As these methods are time consuming, we investigated the more rapidly determined leaf area index (LAI) method to establish the critical nitrogen (Nc) dilution curve, and the curve was used to diagnose plant N status for winter wheat in Guanzhong Plain in Northwest China. Field experiments were conducted using four N fertilization levels (0, 105, 210 and 315 kg ha?1) applied to six wheat cultivars in the 2013–2014 and 2014–2015 growing seasons. LAI, DM, plant N concentration (PNC) and grain yield were determined. Data points from four cultivars were used for establishing the Nc curve and data points from the remaining two cultivars were used for validating the curve. The Nc dilution curve was validated for N-limiting and non-N-limiting growth conditions and there was good agreement between estimated and observed values. The N nutrition index (NNI) ranged from 0.41 to 1.25 and the accumulated plant N deficit (Nand) ranged from 60.38 to –17.92 kg ha?1 during the growing season. The relative grain yield was significantly affected by NNI and was adequately described with a parabolic function. The Nc curve based on LAI can be adopted as an alternative and more rapid approach to diagnose plant N status to support N fertilization decisions during the vegetative growth of winter wheat in Guanzhong Plain in Northwest China. 展开更多
关键词 winter wheat leaf area INDEX CRITICAL NITROGEN concentration NITROGEN nutrition INDEX NITROGEN diagnosis
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Soil Nitrogen Distribution and Plant Nitrogen Utilization inDirect-Seeded Rice in Response to Deep Placement of BasalFertilizer-Nitrogen 预览
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作者 WANG Danying YE Chang +4 位作者 XU Chunmei WANG Zaiman CHEN Song CHU Guang ZHANG Xiufu 《水稻科学:英文版》 CSCD 2019年第6期404-415,共12页
Deep placement of controlled-release fertilizer increases nitrogen (N) use efficiency in rice planting but is expensive. Few studies on direct-seeded rice have examined the effects of deep placement of conventional fe... Deep placement of controlled-release fertilizer increases nitrogen (N) use efficiency in rice planting but is expensive. Few studies on direct-seeded rice have examined the effects of deep placement of conventional fertilizer. With prilled urea serving as N fertilizer, a two-year field experiment with two N rates (120 and 195 kg/hm2) and four basal N application treatments (B50, all fertilizer was broadcast with 50% as basal N;D50, D70 and D100 corresponded to 50%, 70% and 100% of N deeply placed as basal N, respectively) were conducted in direct-seeded rice in 2013 and 2014. Soil N distribution and plant N uptake were analyzed. The results showed that deep placement of basal N significantly increased total N concentrations in soil. Significantly greater soil N concentrations were observed in D100 compared with B50 at 0, 6 and 12 cm (lateral distance) from the fertilizer application point both at mid-tillering and heading stages. D100 presented the highest values of dry matter and N accumulation from seeding to mid-tillering stages, but it presented the lowest values from heading to maturity stages and the lowest grain yield for no sufficient N supply at the reproductive stage. The grain yield of D50 was the highest, however, no significant difference was observed in grain yield, N agronomic efficiency or N recovery efficiency between D70 and D50, or between D70 and B50, while D70 was more labor saving than D50 for only one topdressing was applied in D70 compared with twice in other treatments. The above results indicated that 70% of fertilizer-N deeply placed as a basal fertilizer and 30% of fertilizer-N topdressed as a panicle fertilizer constituted an ideal approach for direct-seeded rice. This recommendation was further verified through on-farm demonstration experiments in 2015, in which D70 produced in similar grain yields as B50 did. 展开更多
关键词 direct-seeded RICE NITROGEN FERTILIZER deep PLACEMENT soil NITROGEN DISTRIBUTION NITROGEN utilization
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不同氮素供给水平对84K杨幼苗碳氮代谢的影响 预览
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作者 刘奇峰 李卓蓉 +1 位作者 吴江婷 罗志斌 《林业科学研究》 CSCD 北大核心 2019年第6期63-72,共10页
[目的]解析不同氮素供给水平下杨树幼苗的生长与碳氮代谢特征,对提高木材产量和品质以及科学制定人工林养分管理策略具有重要意义。[方法]分别以高氮、正常氮和低氮供给处理84K杨(Populus alba×P.glandulosa),分析其生长特征与碳... [目的]解析不同氮素供给水平下杨树幼苗的生长与碳氮代谢特征,对提高木材产量和品质以及科学制定人工林养分管理策略具有重要意义。[方法]分别以高氮、正常氮和低氮供给处理84K杨(Populus alba×P.glandulosa),分析其生长特征与碳氮代谢变化特征。[结果]高氮处理增加了净光合速率、根中的蔗糖含量以及叶中的淀粉含量和生物量,促进84K杨的碳代谢;高氮处理促进了84K杨根中NH4^+和NO3^-吸收和积累,提高了谷氨酸合成酶的活性,增加了大多数氨基酸含量以及总氮含量,促进了84K杨的氮代谢。低氮处理降低了净光合速率、叶中的大多数可溶性糖含量和淀粉含量,抑制84K杨的碳代谢;低氮处理会降低植物体内NH4^+、NO3^-含量,降低根中的硝酸还原酶(NR)的活性,降低氨基酸含量以及总氮含量,抑制84K杨的氮代谢。[结论]这些结果表明84K杨中的碳代谢与氮代谢响应环境中的氮素的盈亏变化表现出很高的一致性,即外界环境中氮素充足时,碳代谢随着氮代谢的增加而增加;而外界环境中氮素亏缺时,碳代谢随着氮代谢的降低而降低。 展开更多
关键词 氮素 84K杨 碳氮代谢 氨基酸 蔗糖 碳氮比
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Changes in foliar nitrogen resorption of Phyllostachys edulis with culm development 预览
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作者 Changshun Zhang Chunlan Liu +3 位作者 Wenyuan Zhang Gaodi Xie Shaohui Fan Na Li 《林业研究:英文版》 CAS CSCD 2019年第2期417-427,共11页
Leaf nitrogen resorption is very important to Phyllostachys edulis development because the withdrawn nitrogen can help newly emerging and growing culms.However,few studies have focused on the ontogenetic changes in le... Leaf nitrogen resorption is very important to Phyllostachys edulis development because the withdrawn nitrogen can help newly emerging and growing culms.However,few studies have focused on the ontogenetic changes in leaf nitrogen resorption of P.edulis.Here,we examined the variability in mature leaf nitrogen concentrations(Nm),nitrogen resorption efficiency(NRE)and proficiency(NRP or Ns)and leaf-level nitrogen use efficiency(NUE)of the current-,3rd-and 5th-year culms in P.edulis stands under extensive management.Analyses of variance and correlation indicated that patterns of Nm,NRP,NRE and NUE were markedly affected by culm age and leaf nitrogen status.Nm,Ns and NRE were significant higher in younger(current-year)culms with 1-year lifespan leaves,while NUE was markedly higher in older(3rd-or 5th-year)culms with 2-year lifespan leaves.Significant linear correlations between Nm and NRP,NRE and NUE,Nm and NUE,Ns and NRE were found for each culm age,and Nm was significantly positively correlated to NRE for all culms pooled.Higher proficiency in older culms led to higher NUE and lower NRE,these relationships can be modulated by Nm,which in turn,is restrained by leaf N availability and acquisition.Our results revealed that at the intraspecific level,P.edulis can adjust its leaf NRE,NRP,and leaf-level NUE in concert with culm development.Understanding nitrogen resorption characteristics and NUE of P.edulis can help decision-makers design appropriate deforestation strategies and achieve precise N fertilization for sustainable bamboo forest management. 展开更多
关键词 PHYLLOSTACHYS edulis NITROGEN RESORPTION EFFICIENCY NITROGEN RESORPTION proficiency Nitrogen-use EFFICIENCY Extensive management CULM DEVELOPMENT Precision fertilization
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Nitrogen-cycling microbial community functional potential and enzyme activities in cultured biofilms with response to inorganic nitrogen availability
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作者 Shuangshuang Li Chengrong Peng +3 位作者 Taisheng Chen Chun Wang Liangliang Guo Dunhai Li 《环境科学学报:英文版》 SCIE EI CAS CSCD 2019年第2期89-99,共11页
Biofilms mediate crucial biochemical processes in aquatic ecosystems. It was hypothesized that eutrophication may promote the growth of biofilms, resulting in larger numbers of functional genes. However, the metabolic... Biofilms mediate crucial biochemical processes in aquatic ecosystems. It was hypothesized that eutrophication may promote the growth of biofilms, resulting in larger numbers of functional genes. However, the metabolic activity and the roles of biofilms in N cycling will be affected by ambient inorganic nitrogen availability, not by the abundance of functional genes. Biofilms were cultured either with replete inorganic nitrogen (N-rep) or without exogenous inorganic nitrogen supply (N-def) in a flow incubator, and the N-cycling gene abundances (nifH, N2 fixation;amoA, ammonia oxidation, archaea and bacteria;nirS and nirK, denitrification) and enzyme activities (nitrogenase and nitrate reductase) were analyzed. The results showed that, comparing the N-def and N-rep biofilms, the former contained lower nifH gene abundance, but higher nitrogenase activity (NA), while the latter contained higher nifH gene abundance, but lower NA. Different patterns of NA diel variations corresponded to the dynamic microbial community composition and different stages of biofilm colonization. Ammonia oxidizing bacteria (AOB), detected only in N-def biofilms, were responsible for nitrification in biofilms. N-rep biofilms contained high nirS and nirK gene abundance and high denitrification enzyme activity, but N-def biofilms contained significantly lower denitrification gene abundance and activity. In general, the strong N2 fixation in N-def biofilms and strong denitrification in N-rep biofilms assured the balance of aquatic ecosystems. The results suggested that evaluation of the functional processes of N cycling should not only focus on genetic potential, but also on the physiological activity of biofilms. 展开更多
关键词 CULTURED biofilms NITROGEN AVAILABILITY Nitrogen-cycling enzymes Nitrogen-cycling genes
草甸白浆土稻秆氮利用效率及氮素调控对水稻产量的影响 预览
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作者 王秋菊 焦峰 +3 位作者 刘峰 迟凤琴 姜辉 李鹏绯 《农业工程学报》 EI CAS CSCD 北大核心 2019年第11期86-94,共9页
为明确三江平原草甸白浆土水稻秸秆还田条件下如何进行施肥,以期为秸秆全量还田条件下水稻氮肥的优化施用提供理论依据和技术指导。该文在白浆土上进行了秸秆氮利用试验、秸秆还田氮素优化施用试验、及氮素调控时期的试验研究。结果表明... 为明确三江平原草甸白浆土水稻秸秆还田条件下如何进行施肥,以期为秸秆全量还田条件下水稻氮肥的优化施用提供理论依据和技术指导。该文在白浆土上进行了秸秆氮利用试验、秸秆还田氮素优化施用试验、及氮素调控时期的试验研究。结果表明:通过15N同位素示踪确定,秸秆氮对水稻植株氮素累积量贡献率为6.49%~7.48%,对茎叶氮素累积量的贡献率为3.26%~4.16%,对籽粒贡献率为8.67%~9.74%;秸秆氮素当年总利用率为6.51%~7.65%;调节碳/氮比有利于提高秸秆氮素利用率。大田试验证实秸秆还田条件下施氮量连续3a比常规施氮量减少10%,排水性好的田块有增产效果,3a平均增产6.17%,减氮20%以上产量低而且年际间不稳,减氮时期适合均衡减氮和基肥减氮,蘖肥和穗肥减氮减产极显著;排水性不良田不适合减氮,减氮导致减产。不同土壤秸秆还田后氮素调控有差异,要因地制宜根据土壤条件制定相应的氮素管理措施。 展开更多
关键词 土壤 秸秆 白浆土 秸秆还田 15N标记 氮利用率 氮素调控 产量
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晚播对弱筋小麦植株氮素积累与利用的影响 预览
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作者 李瑞 杨兵兵 +5 位作者 吴培金 闫素辉 张从宇 许峰 邵庆勤 李文阳 《云南农业大学学报:自然科学版》 CSCD 北大核心 2019年第5期754-761,共8页
【目的】分析晚播对弱筋小麦氮素积累与利用的影响。【方法】以弱筋小麦品种扬麦13和宁麦13为材料,在不同氮素水平下(N210:210 kg/hm^2、N270:270 kg/hm^2)设置适播与晚播处理,分析弱筋小麦氮素积累与利用情况。【结果】弱筋小麦开花期... 【目的】分析晚播对弱筋小麦氮素积累与利用的影响。【方法】以弱筋小麦品种扬麦13和宁麦13为材料,在不同氮素水平下(N210:210 kg/hm^2、N270:270 kg/hm^2)设置适播与晚播处理,分析弱筋小麦氮素积累与利用情况。【结果】弱筋小麦开花期植株氮素积累量主要来源于土壤氮(70.48%~85.51%);成熟期籽粒氮素积累量主要来源于土壤氮(74.35%~86.86%);成熟期营养器官氮素积累主要来源于肥料氮(52.88%~82.12%)。与适期播种相比,晚播显著增加了小麦成熟期单株氮素积累量、开花期来源于土壤氮的积累量、成熟期营养器官和籽粒来源于土壤氮及肥料氮的积累量。弱筋小麦花前营养器官积累氮素向籽粒的转运率为55.52%~79.78%,氮素积累转移的贡献率为38.91%~77.99%。适期播种处理下,花前营养器官氮素积累转运量、转运率与贡献率分别为23.47 mg/株、75.23%和71.46%,而晚播显著降低花前营养器官氮素积累转运量、转运率与贡献率(分别为19.87 mg/株、59.74%和50.31%)。各处理小麦氮肥生产效率为25.25~44.27 kg/kg,氮素利用效率为15.75%~41.43%,氮素收获指数为0.730~0.844。同一因素下不同水平比较表明:晚播显著降低籽粒产量、氮肥生产效率、氮素利用效率及氮素收获指数,但播期对籽粒蛋白质含量无显著影响。在相同品种和氮水平处理下,晚播较适期播种籽粒产量降低。【结论】弱筋小麦晚播不利于籽粒产量的提高和氮素利用效率的提高,因此为获得较高产量水平与氮素利用效率,应尽量保证弱筋小麦适宜播种期。 展开更多
关键词 弱筋小麦 晚播 氮素 氮肥利用率
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秸秆还田及氮肥调控对不同肥力白浆土氮素及水稻产量影响 预览
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作者 王秋菊 刘峰 +5 位作者 迟凤琴 焦峰 张春峰 姜辉 李鹏绯 朱宝国 《农业工程学报》 EI CAS CSCD 北大核心 2019年第14期105-111,共7页
三江平原是黑龙江省水稻主要种植区,白浆土是主要种稻土壤,在白浆土上开展秸秆还田试验研究,明确白浆土秸秆还田效果,根据土壤肥力水平调控氮素为秸秆还田提出因地制宜的土壤、施肥等管理技术提供参考。该文以白浆土为供试土壤,比较研... 三江平原是黑龙江省水稻主要种植区,白浆土是主要种稻土壤,在白浆土上开展秸秆还田试验研究,明确白浆土秸秆还田效果,根据土壤肥力水平调控氮素为秸秆还田提出因地制宜的土壤、施肥等管理技术提供参考。该文以白浆土为供试土壤,比较研究不同肥力白浆土上连续秸秆还田及调控氮素对水稻产量及土壤养分变化的影响。结果得出:高肥力土壤连续秸秆还田适合减氮,减氮10%连续3年水稻不减产,增产幅度为0.1%~6.94%,减氮20%以上产量降低,秸秆连续还田增加氮素水稻产量第1年与正常施肥比增产4.47%,第2年水稻产量比对照减产4.02%~31.86%,调氮降低幅度大;中、低肥力土壤秸秆还田水稻产量第1年比对照分别增加1.48%,4.52%,第2年调氮增产幅度会下降;秸秆还田使土壤有机质、氮素含量提高,在高肥力土壤上氮素过高使水稻前期分蘖量增多,水稻有效穗数降低,产量降低,减氮后可以避免土壤氮素过剩,水稻产量提高;中、低肥力土壤秸秆还田有利于增加土壤肥力水平,适当增加氮素可使水稻产量提高。 展开更多
关键词 土壤 氮素 水稻 秸秆还田 产量 氮肥调控 白浆土 不同肥力
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碳氮添加对雨养农田土壤全氮、有机碳及其组分的影响 预览
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作者 江晶 武均 +2 位作者 张仁陟 董博 蔡立群 《水土保持学报》 CSCD 北大核心 2019年第3期215-220,227共7页
为探明碳氮添加4年后,土壤全氮、有机碳及其组分(可溶性有机碳、微生物量碳、轻组和重组有机碳)的变化特征,依托布设于甘肃省定西市安定区李家堡镇的不同碳源配施氮素田间定位试验,涉及秸秆、生物质炭、氮素3个因素,秸秆设置为不施、施... 为探明碳氮添加4年后,土壤全氮、有机碳及其组分(可溶性有机碳、微生物量碳、轻组和重组有机碳)的变化特征,依托布设于甘肃省定西市安定区李家堡镇的不同碳源配施氮素田间定位试验,涉及秸秆、生物质炭、氮素3个因素,秸秆设置为不施、施用秸秆2水平;生物质炭为不施和施用生物质炭2个水平;氮素设置为不施氮、施纯氮50 kg/hm~2、施纯氮100 kg/hm~2 3个水平,共9个处理。结果表明:不同处理下土壤全氮、有机碳及其组分的含量均随土层的加深而降低。添加生物质炭对土壤全氮、有机碳及其组分均具有不同程度的提升效应。添加秸秆对土壤全氮、有机碳和可溶性有机碳、微生物量碳、轻组有机碳均具有显著提升效应,仅在0-5 cm土层对重组有机碳有显著提高。添加氮素可显著提升土壤全氮、有机碳和可溶性有机碳、微生物量碳、轻组有机碳含量。较其他处理,添加生物质炭对土壤全氮、有机碳和重组有机碳的提升效应最高,添加秸秆对可溶性有机碳、微生物量碳、轻组有机碳的提升效果最优。从提升土壤质量的角度出发,推荐秸秆配施氮素模式,该模式下土壤碳素有效性高、易于被微生物利用,有利于作物生长。从提高土壤固碳角度考虑,推荐生物质炭配施氮素模式,该模式有利于碳的封存。 展开更多
关键词 生物质炭 秸秆 氮素 全氮 有机碳组分
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Nitrogen additions inhibit nitrification in acidic soils in a subtropical pine plantation:effects of soil pH and compositional shifts in microbial groups 预览
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作者 Liang Kou Xinyu Zhang +3 位作者 Huimin Wang Hao Yang Wei Zhao Shenggong Li 《林业研究:英文版》 CAS CSCD 2019年第2期669-678,共10页
Plantation forests play a pivotal role in carbon sequestration in terrestrial ecosystems,but enhanced nitrogen(N)deposition in these forests may affect plantation productivity by altering soil N cycling.Hence,understa... Plantation forests play a pivotal role in carbon sequestration in terrestrial ecosystems,but enhanced nitrogen(N)deposition in these forests may affect plantation productivity by altering soil N cycling.Hence,understanding how simulated N deposition affects the rate and direction of soil N transformation is critically important in predicting responses of plantation productivity in the context of N loading.This study reports the effects of N addition rate(0,40,and 120 kg N ha^-1 a^-1)and form(NH4Cl vs.NaNO3)on net N mineralization and nitrification estimated by in situ soil core incubation and on-soil microbial biomass determined by the phospholipid fatty acid(PLFA)method in a subtropical pine plantation.N additions had no influences on net N mineralization throughout the year.Net nitrification rate was significantly reduced by additions of both NH4Cl(71.5)and NaNO3(47.1%)during the active growing season,with the stronger inhibitory effect at high N rates.Soil pH was markedly decreased by 0.16 units by NH4Cl additions.N inputs significantly decreased the ratio of fungal-to-bacterial PLFAs on average by 0.28(49.1%)in November.Under NH4Cl additions,nitrification was positively related with fungal biomass and soil pH.Under NaNO3 additions,nitrification was positively related with all microbial groups except for bacterial biomass.We conclude that simulated N deposition inhibited net nitrification in the acidic soils of a subtropical plantation forest in China,primarily due to accelerated soil acidification and compositional shifts in microbial functional groups.These findings may facilitate a better mechanistic understanding of soil N cycling in the context of N loading. 展开更多
关键词 ACIDIFICATION Atmospheric NITROGEN deposition MICROBIAL functional group NITRIFICATION Soil NITROGEN transformation
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Estimating total leaf nitrogen concentration in winter wheat by canopy hyperspectral data and nitrogen vertical distribution 预览
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作者 DUAN Dan-dan ZHAO Chun-jiang +6 位作者 LI Zhen-hai YANG Gui-jun ZHAO Yu QIAO Xiao-jun ZHANG Yun-he ZHANG Lai-xi YANG Wu-de 《农业科学学报:英文版》 SCIE CAS CSCD 2019年第7期1562-1570,共9页
The use of remote sensing to monitor nitrogen(N) in crops is important for obtaining both economic benefit and ecological value because it helps to improve the efficiency of fertilization and reduces the ecological an... The use of remote sensing to monitor nitrogen(N) in crops is important for obtaining both economic benefit and ecological value because it helps to improve the efficiency of fertilization and reduces the ecological and environmental burden.In this study,we model the total leaf N concentration(TLNC) in winter wheat constructed from hyperspectral data by considering the vertical N distribution(VND).The field hyperspectral data of winter wheat acquired during the 2013–2014 growing season were used to construct and validate the model.The results show that:(1) the vertical distribution law of LNC was distinct,presenting a quadratic polynomial tendency from the top layer to the bottom layer.(2) The effective layer for remote sensing detection varied at different growth stages.The entire canopy,the three upper layers,the three upper layers,and the top layer are the effective layers at the jointing stage,flag leaf stage,flowering stages,and filling stage,respectively.(3) The TLNC model considering the VND has high predicting accuracy and stability.For models based on the greenness index(GI),mND705(modified normalized difference 705),and normalized difference vegetation index(NDVI),the values for the determining coefficient(R2),and normalized root mean square error(nRMSE) are 0.61 and 8.84%,0.59 and 8.89%,and 0.53 and 9.37%,respectively.Therefore,the LNC model with VND provides an accurate and non-destructive method to monitor N levels in the field. 展开更多
关键词 NITROGEN concentration HYPERSPECTRAL vertical NITROGEN distribution WINTER wheat
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The Protective Role of a Riparian Vegetation to the Sources of a Rural Watershed 预览
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作者 Fernando Frachone Neves Auré +2 位作者 lio Teodoro Fontes André Luiz Oliveira 《水资源与保护(英文)》 2019年第4期419-433,共15页
A recent review of the Brazilian forest law has suggested the possibility of decrease the riparian buffer width along the banks of waterways. This vegetation can trap solutes which had been deposited in the soil and w... A recent review of the Brazilian forest law has suggested the possibility of decrease the riparian buffer width along the banks of waterways. This vegetation can trap solutes which had been deposited in the soil and which would otherwise be carried to the waterways in runoff water. In the current study, we applied the AVSWAT model to the Rio Bonito micro-basin of city of Descalvado, State of S?o Paulo, Brazil, to verify the amount of nitrogen (N) and phosphorous (P) entering the water resource, and to evaluate the environmental protection provided by the riparian vegetation zones. Our results demonstrate this protection is effective in reducing the amount of nitrogen (N) and phosphorous (P) carried to the river. The scenario produced by the data could be used to diagnose the contamination of this particular watershed and to indicate the measures that should be adopted to ensure the restoration and preservation of riparian vegetation zones. 展开更多
关键词 AVSWAT WATERSHED EROSION NITROGEN Phosphorous
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氮钾肥配施对辽东南地区玉米生长及氮素积累的影响 预览
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作者 樊叶 樊琳琳 +3 位作者 薛兵东 王秀凤 付俊 张丽丽 《河北农业大学学报》 CAS CSCD 北大核心 2019年第1期8-13,共6页
试验针对辽东南地区气候特点,设置二因素裂区试验,研究不同氮、钾肥配施对玉米生长特性及养分吸收规律的影响。结果表明:氮肥可有效延长叶片的功能期,减缓吐丝期至灌浆期LAI的下降幅度,下降幅度依次为N300(2.69%)<N180(16.13%)<N9... 试验针对辽东南地区气候特点,设置二因素裂区试验,研究不同氮、钾肥配施对玉米生长特性及养分吸收规律的影响。结果表明:氮肥可有效延长叶片的功能期,减缓吐丝期至灌浆期LAI的下降幅度,下降幅度依次为N300(2.69%)<N180(16.13%)<N90(28.62%)<N0(46.84%);植株氮素积累的2个主要阶段分别在大喇叭口期至吐丝期和吐丝期至灌浆期,N300、N180、N90和N0从大喇叭口期至灌浆期的氮素积累量分别占整个生育期氮素积累量的65%、63%、51%和60%;氮、钾肥对玉米产量、吐丝期和灌浆期的LAI及灌浆期和成熟期的氮素积累量有显著的互作效应;在辽东南地区,氮、钾肥通过促进玉米植株营养生长,提高群体的LAI和叶片叶绿素含量,增强群体光合能力的同时,还通过促进植株对氮、钾元素的吸收与利用,提高植株的氮素积累能力,从而实现玉米高产。 展开更多
关键词 玉米 氮肥 钾肥 氮素积累 辽东南地区
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基于便携式作物生长监测诊断仪的江西双季稻氮肥调控研究 预览
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作者 李艳大 舒时富 +5 位作者 陈立才 叶春 黄俊宝 孙滨峰 王康军 曹中盛 《农业工程学报》 EI CAS CSCD 北大核心 2019年第2期100-106,共7页
建立基于便携式作物生长监测诊断仪的江西双季稻氮肥调控模型,利用模型推荐穗肥追氮量,实现江西双季稻氮肥追施的精确管理。基于不同株型品种和氮肥处理的田间试验资料,构建了双季稻叶面积指数光谱监测模型,利用拔节期的差值植被指数实... 建立基于便携式作物生长监测诊断仪的江西双季稻氮肥调控模型,利用模型推荐穗肥追氮量,实现江西双季稻氮肥追施的精确管理。基于不同株型品种和氮肥处理的田间试验资料,构建了双季稻叶面积指数光谱监测模型,利用拔节期的差值植被指数实时估测叶面积指数,进而结合江西双季稻高产栽培经验和建立的氮肥调控模型,对双季稻穗肥追氮量进行实时推荐,并和当地农户施肥方案和产量进行比较。双季稻关键生育期(分蘖期、拔节期、孕穗期、抽穗期和灌浆期)的冠层差值植被指数DVI(810,720)与叶面积指数均呈显著正相关,线性函数拟合效果优于其他函数。利用独立试验资料对所建模型进行了检验,单生育期的模型预测效果优于全生育期模型;其中,拔节期的光谱监测模型表现最佳,早稻和晚稻叶面积指数的光谱监测模型的R2分别为0.8806和0.8788,模型预测早稻和晚稻叶面积指数的均方根误差、相对均方根误差、相关系数分别为0.30和0.25、7.28%和6.18%、0.9232和0.9269。氮肥调控模型推荐施肥应用表明,紧凑型品种的穗肥用量高于松散型品种;与农户方案相比,氮肥调控模型推荐施肥的调控方案在产量不降低的情况下减少氮肥用量6.58kg/hm^2,提高氮肥农学利用率0.82个百分点、净收益103元/hm^2和产投比0.9,而产量比农户方案略高或持平。与传统非定量农户施肥法相比,基于便携式作物生长监测诊断仪的双季稻氮肥调控方法可在保证产量的情况下,减少施氮量,提高氮肥农学利用率,获得更高经济效益,在江西双季稻生产中具有推广应用价值。 展开更多
关键词 肥料 作物 便携式作物生长监测诊断仪 双季稻 差值植被指数 氮肥调控 叶面积指数 产量
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Isotope analysis of nitrate pollution sources in groundwater of Dong'e geohydrological unit 预览
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作者 LI Yang KANG Feng-Xin ZOU An-de 《地下水科学与工程:英文版》 2019年第2期145-154,共10页
As nitrate pollution in groundwater has become increasingly serious in recent years, nitrogen isotope was adopted in this paper to define its sources in a typical agricultural area of Dong5e hydrogeological unit. The ... As nitrate pollution in groundwater has become increasingly serious in recent years, nitrogen isotope was adopted in this paper to define its sources in a typical agricultural area of Dong5e hydrogeological unit. The results show that: Higher content of NO3^- detected in shallow groundwater is 27.77 mg/L on average and δ^15N content ranges from 7.8‰ to 12 ‰, indicating that shallow groundwater is mainly contaminated by sewage or feces. In contrast, less NO3^- in deep groundwater (karst water) has an average value of 12.81 mg/L and δ^15N content is between 7.2‰ and 14.3‰, which is closely related to human disturbance as mentioned above. In addition, considering relatively low groundwater quality at some monitoring sites, reasonable fertilization is a better choice in the study area to reduce nitrate source in groundwater. 展开更多
关键词 NITROGEN ISOTOPE GROUNDWATER NITROGEN POLLUTION source AGRICULTURAL area
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9个主要南方人工林树种叶片化学计量学特征研究 预览
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作者 王家妍 魏国余 +2 位作者 韦铄星 莫雅芳 蒋燚 《广东农业科学》 CAS 2019年第5期48-53,共6页
【目的】通过研究9个主要南方人工林树种叶片N、P、K化学计量学特征,丰富主要人工林树种化学计量学基础数据,为我国南方地区林木种植和管护提供决策依据。【方法】野外平均木叶片采集,室内进行化学测定分析N、P、K含量。【结果】9个树... 【目的】通过研究9个主要南方人工林树种叶片N、P、K化学计量学特征,丰富主要人工林树种化学计量学基础数据,为我国南方地区林木种植和管护提供决策依据。【方法】野外平均木叶片采集,室内进行化学测定分析N、P、K含量。【结果】9个树种叶片的N、P、K含量均值分别为13.90、1.39、8.70 mg/g,不同树种间的N、P、K含量存在极显著差异,厚荚相思N、P、K含量高于其他树种, 9个树种叶片的N∶P、N∶K和K∶P变化范围为7.79~17.79、1.15~2.16、0.07~0.25。不同树种N和P含量呈极显著正相关关系,存在协同作用。不同生活型树种叶片N和P元素含量存在极显著差异,表现为阔叶树种N和P含量明显大于针叶林。【结论】9个主要南方人工林树种生长主要受到N元素限制,在林分后期管理上应加强养分管理、增施氮肥。 展开更多
关键词 氮磷比 化学计量学 阔叶树种 针叶树种
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氮水平对盆栽芍药生长发育及氮代谢的影响 预览
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作者 李兆鹏 姜楠南 +3 位作者 孙音 王媛 房义福 徐金光 《山东林业科技》 2019年第5期13-17,共5页
为了解促成栽培盆栽芍药氮代谢的生理特性,提高氮肥利用率,本实验采用单因子四水平随机试验,氮肥浓度设4个水平,氮源为尿素,以液肥(霍格兰营养液)形式施用,施用浓度分别为0mg/L、150mg/L、300mg/L、450mg/L。结果表明:(1)施氮显著提高... 为了解促成栽培盆栽芍药氮代谢的生理特性,提高氮肥利用率,本实验采用单因子四水平随机试验,氮肥浓度设4个水平,氮源为尿素,以液肥(霍格兰营养液)形式施用,施用浓度分别为0mg/L、150mg/L、300mg/L、450mg/L。结果表明:(1)施氮显著提高了芍药株高、地茎、冠幅、开花数量以及花径。(2)在一定氮素范围内(0-300mg/L),硝酸还原酶(Nr)活性、谷氨酰胺合成酶(GS)活性、谷氨酸合成酶(GOGAT)活性以及谷氨酸脱氢酶(GDH)活性与供氮水平成正相关,当氮素过量时虽然能提高硝酸还原酶(Nr)活性、谷氨酸脱氢酶(GDH)活性,但谷氨酰胺合成酶(GS)活性、谷氨酸合成酶(GOGAT)活性却有所下降。 展开更多
关键词 芍药 促成栽培 氮代谢
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Swedish Experience and Excellence in Wastewater Treatment Demonstrated Especially in Phosphorus Removal 预览
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作者 Stig Morling 《水资源与保护(英文)》 2019年第3期333-347,共15页
Water quality protection in Sweden has a more than 80-year history. The needed knowledge has by large been imported. Now, to some extent the development of phosphorus removal technology may be Swedish contribution to ... Water quality protection in Sweden has a more than 80-year history. The needed knowledge has by large been imported. Now, to some extent the development of phosphorus removal technology may be Swedish contribution to advanced knowledge. This paper presents the development in Sweden, mainly a close to 50-year period. Starting in the late 1960s, a standard of <0.5 mg P/l was the normally raised effluent criteria, regardless of the magnitude of the discharge flow. The successive sharpening of the discharge levels has today resulted in a level of 0.2 to 0.3 mg P/l typically. As a matter of fact, even levels of 0.1 to 0.15 mg P/l have been discussed. The period should a large extent demonstrated both improved technologies and a far better efficiency with respect to the use of chemicals and energy. Some important points in this development may be the understanding of the Oxygen Consumption Potential, as well as the identified needs for an improved nitrogen removal. Lately the problems of complex pollution agents and predominantly the remains of pharmaceutical agents have been identified. To illustrate the development during the 50-year period, two examples are presented from the Swedish context. The main conclusion in this paper is that the Swedish history on phosphorus removal illustrates how empirical science in practice sometimes works, including a never-ending need for an open mind and a readiness to take revised and improved knowledge on board. 展开更多
关键词 WASTE Water Treatment PHOSPHORUS Separation Techniques Oxygen CONSUMPTION Potential NITROGEN
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