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The objective of this study was to determine the efficiency of different plant systems in capturing deep soil nitrate （NO3-） to reduce NO3- leaching in a field plot experiment using 15N labelling. The study was conducted on a calcareous alluvial soil on the North China Plains and the plant systems evaluated included alfalfa （Medicago sativa）, American black poplar （Populus nigra） and cocksfoot （Dactylis）. ^15N-labelled N fertilizer was injected to 90 cm depth to determine the recovery of ^15N by the plants. With conventional water and nutrient management, the total recovery of ^15N-labeled NO3--N was 23.4% by alfalfa after two consecutive growth years. The recovery was significantly higher than those by American black poplar （12.3%） and cocksfoot （11.4%）. The highest proportion of soil residual ~SN from the labeled fertilizer N （%Ndff） was detected around 90 cm soil depth at the time of the 1st year harvest and at 110-130 cm soil depth at time of the 2nd year harvest. Soil %Ndff in 0-80 cm depth was significantly higher in the alfalfa treatment than those in all the other treatments. The soil %Ndff below 100 cm depth was much lower in the alfalfa than those in all the other treatments. These results indicated that ^15N leaching losses in the alfalfa treatment were significantly lower than by those in the black poplar and cocksfoot treatments, due to the higher root density located in nitrate labeling zone of soil profile. In conclusion, alfalfa may be used as a plant to capture deep soil NO3- left from previous crops to reduce NO3- leaching in high intensity crop cultivation systems of North China Plain. 相似文献
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The purpose of the investigation was to assess the opportunity to use spring waters as indicator for the load state of rural landscape ecosystems. In the periods from 2000-2003 and 2011-2012, the physical and chemical water quality of 55 freshwater springs in the German federal state of the Saarland was investigated in monthly intervals. The catchment areas of the springs represented the prevailing geological formations in the Saarland as well as the main land use types such as forest, grassland and arable land. The results show a clear correlation between the nitrate content and the share of arable land in the closer catchment area of the springs. The problem of acidification and related processes occurs mainly at the sites with acid parent rock material and accordingly substrates deficient in lime. Very low pH-values between 4 and 5 are observed and the aluminum concentration levels are consistently increased. Especially at sites with low calcium content in the geological substrate, a progressive destruction of the clay minerals can be assumed. In the extremely acidic spring waters, which showed the highest aluminum contamination during the measurement 10 years ago, the aluminum-values decreased slightly. This indicates that the clay minerals in these locations are already completely destroyed. Thus, it can be concluded that the investigation of spring waters provides information on the geo-ecological conditions in catchment areas. By means of the multi-temporal approach, changes of land use or other influences by human activities can be detected. 相似文献
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不同氮肥及配比对韭菜产量和品质的影响 总被引：2，自引：1，他引：1
采用盆栽方式研究了不同浓度的尿素、硝酸钙和硫酸铵以及硝酸钙和硫酸铵的不同配比对韭菜产量、硝酸盐含量和营养品质的影响。结果表明,3种肥料中,尿素可提高韭菜产量和可溶性蛋白含量,硝酸钙提高维生素C含量,硫酸铵提高可溶性糖含量、降低硝酸盐含量。分别使用0.6%尿素、0.4%硫酸铵、0.6%硝酸钙,以及3:2和2:3的硝铵比进行追肥处理,对提高韭菜产量,降低硝酸盐含量,增加维生素C、可溶性糖和可溶性蛋白含量的效果最好。 相似文献
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The effects of three nitrogen sources （ammonium, nitrate and ammonium＋nitrate） and three salt treatments （0, 100 and 200 mM NaCl） on nitrate reductase activity, proline, soluble protein and carbohydrate contents in psylliom （Plantago ovata） plants were Studied. The nitrate reductase activity tended to increase when NO3- was included in the root-zone solution, but decrease as salinity increased. All N sources stimulated plant growth and nutrient uptake. Shoot and root dry matter tended to decrease as salinity increased, but less so when both NH4＋ and NO3- were present. Shoot biomass accumulated to significantly greater quantities under the mixed-N treatments than when produced using either NH4＋ or NO3- N-form alone. Although not statistically significant, the root biomasses showed a similar tendency. Generally, leaf proline and soluble shoot carbohydrate contents increased with increasing salinity in contrast to soluble protein which decreased regardless of the N source. Under salinity conditions, the concentration of Na＋ in shoot and root tissues was highest in ammonium-N treatment, while that of K＋ was highest in the mixed-N treatment. 相似文献
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施肥对油菜产量及其硝酸盐含量的影响 总被引：2，自引：0，他引：2
采用盆栽试验研究了施肥对油菜产量和硝酸盐含量的影响。结果表明,无公害油菜生产施用无机肥,以磷酸二氢铵为佳,碳酸氢铵次之,尿素相应效果最差,施用无机肥氮素用量以不超过375kg/hm2为宜;采取"攻前期控后期,重基肥轻追肥"的氮肥施用策略,有利于保证其上市时的质量;氮肥与有机肥配合施用,尿素与马粪配施比例以1∶2为最佳;尿素与牛粪的总施氮量应控制在750kg/hm2以下,且其配比中尿素氮用量应低于1∶3。 相似文献
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A field experiment was conducted to investigate the variations in denitrification losses and N2O emissions from 4 different types of nitrogen fertilizers (urea, ammonium nitrate, ammonium bicarbonate, and calcium nitrate) applied to the maizefluvo-aquic soil system in the North China Plain by the method of intact soil core incubation and acetylene inhibition, and the responses of nitrogen fertilizers to maize grain yields. Results show that the denitrification loss from different nitrogen fertilizers ranged from 0.38-1.20 kg N ha-1, with no significant differences among different fertilizer treatments, and the N2O emission from 0.05-0.95 kg N ha-1, with a significant difference (P＜0.05) among the treatments. The highest emission was from the treatment of ammonium nitrate, while the lowest from calcium nitrate. The nitrogen fertilizers increased the maize grain yield by 9.7-19.8% compared to control. But there were no significant differences in yield increase among the 4 types of nitrogen fertilizers. In comparison, urea had the best effect, whereas calcium nitrate had the least effect on increasing maize yield. The maize yield was 5.7% higher when urea was separately applied at 2 times than when it was applied at a time. In this case, however, the denitrification loss and the N2O emission were also increased by 4.05 and 1.84 kg N ha-1,respectively. 相似文献
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在溶液培养条件下研究了不同氮素形态对菠菜生长及叶片抗氧化酶活性的影响.结果表明,适当提高供铵比例能显著增加菠菜生物量,硝/铵比为50/50时菠菜的生物量最高.菠菜叶片的MDA含量随硝/铵比例由100/0降至50/50时略有下降,而完全供铵时MDA含量显著提高.菠菜叶片SOD活性随硝/铵比例由100/0降到50/50时显著升高,再降低NO3--N比例SOD活性则显著下降;而POD和CAT活性则随NO3--N/NH4+-N比例由100/0降低到50/50时显著降低,进一步提高NH4+-N比例则显著提高POD和CAT活性.而叶片游离脯氨酸的含量随着硝/铵比例的下降先显著提高后明显降低,在硝/铵比为50/50时,脯氨酸含量最低.可见在本试验条件下,营养液中硝/铵比为50/50时菠菜遭受氧化胁迫的程度较小. 相似文献
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氮肥对尖叶菠菜硝酸盐积累的影响 总被引：4，自引：2，他引：2
研究了不同尿素施用量对尖叶菠菜生物量、硝酸盐含量和硝酸还原酶活性的影响.结果表明:3项指标均随着尿素用量的增加而增加,与对照相比,差异极显著.从保证产量、减少成本和降低硝酸盐污染综合考虑,菠菜尿素施用量以少于33.7kg/667m2为宜. 相似文献
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在不同培养方式(水培和土培)下，选择4种不同基因型水稻(常规籼稻、杂交籼稻、常规粳稻、杂交粳稻)，研究其苗期NH4^ 及硝酸还原酶抑制剂对NO3^-吸收的影响。结果表明：土培条件下，NH4^ 对NO3^-吸收的抑制主要表现在粳稻上，对杂交粳稻的抑制尤为明显；硝酸还原酶抑制剂对粳稻NO3^-吸收的抑制程度大于其对籼稻的抑制。水培条件下，NH4^ 能较大程度地降低杂交粳稻对N3^-的吸收；在硝酸还原酶活性(NRA)受抑制后，对杂交粳稻NO3^-吸收的影响却很小，说明NH4^ 对NO3^-吸收的影响并非完全通过影响硝酸还原酶的活性来完成。 相似文献
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不同铵硝比对菠菜有机酸和淀粉含量的影响 总被引：1，自引：0，他引：1
【目的】研究不同铵硝比的氮素营养对于菠菜有机酸和淀粉含量的影响。【方法】采用营养液栽培菠菜的方法,营养液中的氮素形态设置硝态氮和铵态氮以一定比例（100﹕0、75﹕25、50﹕50、25﹕75 和 0﹕100）配合。【结果】随着铵硝比的下降,（1）菠菜茎叶丙酮酸、柠檬酸、α-酮戊二酸、琥珀酸、延胡索酸和苹果酸等6种有机酸含量以及淀粉含量都呈上升趋势;同时,有机酸含量与营养液中初始硝态氮浓度之间呈显著的线性正相关关系;（2）菠菜根系丙酮酸、柠檬酸、琥珀酸和苹果酸含量以及淀粉含量也呈上升趋势,但延胡索酸含量的变化不明显;（3）除了柠檬酸外,菠菜根系其它5种有机酸含量与其茎叶中相应有机酸含量的比值都呈现下降的趋势;在全硝营养条件下,根系中只有琥珀酸和延胡索酸的含量低于其在茎叶中的含量;而在全铵营养时,菠菜根系中上述5种有机酸的含量均明显高于茎叶中的相应有机酸的含量。因此,与根系相比,菠菜茎叶中5种有机酸含量随营养液中硝态氮比例增加而增加的幅度更明显。而随着营养液中硝态氮比例的增加,菠菜根系柠檬酸含量与其茎叶柠檬酸含量的比值逐渐升高,则说明根系柠檬酸含量增加的幅度要大于茎叶柠檬酸含量;（4）菠菜的茎叶和根系中的淀粉含量都呈现下降的趋势,且与营养液中硝态氮浓度之间均呈现为显著的负相关关系。【结论】随着营养液中硝态氮比例的增加,菠菜茎叶和根系有机酸代谢均表现为增强的趋势。 相似文献
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不同氮肥配施对马铃薯块茎形成及发育的影响 总被引：1，自引：0，他引：1
以尿素、硫酸铵和硝酸钙为氮源,分别在基肥和追肥中选择不同氮肥施用,确定不同氮肥配施对马铃薯块茎形成和发育的影响。结果表明,与单施尿素相比,配施硫酸铵或硝酸钙可不同程度促进块茎形成和发育。其中,硫酸铵作基肥施用块茎总产量分别增加16.7%(2016年)和33.5%(2017年)(P0.05),商品薯产量增加20.1%(2016年)和40.7%(2017年)(P0.05);而硝酸钙作追肥施用块茎总产量增加10.4%(2016年)和26.2%(2017年)(P0.05),商品薯产量增加15.0%(2016年)和32.8%(2017年)(P0.05)。 相似文献
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Biogas production generates digested slurry as a byproduct. It can be used as a fertilizer especially after its conversion into digested liquid. A pot based study was conducted in order to evaluate the effect of the application of digested liquid on CH4 and N2O flux, and plant biomass in paddy. Analysis revealed that digested liquid treated soils released more CH4 compared to ammonium sulphate and the control. Ammonium sulphate treated soil emitted the highest N20 whereas digested liquid application decreased its emission significantly. Further, the cumulative emission over 101 d of the experiment was found to be higher for CHa （16.9 to 29.9 g m^-2） compared to N20 （-49.3 to 18.9 mg m^-2） for all treatments. Digested liquid application had positive impact on plant variables such as panicle number and weight of panicles. This study suggests that digested liquid application significantly decrease N20 emission and increase CH4 emission possibly due to affecting the availability of organic C in the soil to microbial activity for methanogenesis. Another possibility for enhancing CH4 emission by following biogas digested liquid could be attributed to the increase in plant biomass. 相似文献
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供氮水平和有机无机配施对片麻岩土壤谷子生长及土壤硝态氮的影响 总被引：1，自引：0，他引：1
在片麻岩新成山地土壤上,设置0,120和300 kg/hm2 3个施氮量,以不施氮肥(CK)为对照,在每个施氮水平下设置了50％有机肥50％尿素(用Y表示)和100％尿素(用N表示)2个副处理,研究了不同氮素水平下有机无机肥料配施对谷子生长及土壤硝态氮的影响.结果表明:在该试验条件下,与不施氮肥处理(CK)相比,各施氮处理的谷子产量均显著增加,当施氮量达到120 kg/hm2时产量达到最高,之后施氮量提高到300 kg/hm2谷子产量并没有显著增加;从0～60 cm土壤剖面中硝态氮分布的差异可以看出:在相同施肥方式下,土壤的硝态氮含量随施氮量的增加而增加,以0～40 cm土层变化最明显,有机肥与尿素配合施用,可以协调土壤氮素的供应,显著降低土壤NO3--N的含量. 相似文献
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不同氮肥及用量对潍县萝卜硝酸盐和亚硝酸盐含量的影响 总被引：2，自引：0，他引：2
试验研究硝酸铵、碳酸氢铵和尿素三种氮肥及用量对潍县萝卜硝酸盐和亚硝酸盐含量的影响。结果表明：潍县萝卜的硝酸盐含量与施肥量呈正相关,而亚硝酸盐含量与施肥量无正相关关系;不同氮肥处理对潍县萝卜硝酸盐含量的影响,以硝酸铵处理较高,尿素处理居中,碳酸氢铵较低,但均高于对照;三种氮肥处理,对潍县萝卜亚硝酸盐含量影响的大小顺序为尿素〉碳酸氢铵〉硝酸铵。 相似文献
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用数值反应和实验种群生命表分析胡瓜钝绥螨的控制能力 总被引：11，自引：1，他引：11
在华北平原玉米-潮土系统中,采用原状土柱培养乙炔抑制法研究尿素、硝酸铵、碳酸氢铵和硝酸钙4种氮肥品种的反硝化损失和 N2O 排放量。结果表明,氮肥品种的反硝化损失量为 0.38～1.20 kgN·ha-1,品种间无显著差异;N2O 排放量为 0.05～0.95 kgN·ha-1,品种间差异显著。硝酸铵排放量最高,硝酸钙最低。尿素分 2 次施用比 1 次施用显著或极显著增加反硝化损失量和N2O 排放量,分别增加 4.05 和 1.84 kgN·ha-1。施用氮肥极显著增加玉米产量,增产率达9.7%～19.8% 相似文献
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为探究不同土壤类型下适合小麦生长的氮肥种类，以‘豫教5号’为供试材料，于2017—2018年在河南省临颍县开展盆栽试验，设置潮土（SC）、黄褐土（SH）、砂姜黑土（SS）三种土壤类型；尿素（UR）、硝酸铵(AN)、硫酸铵(AS)、硝酸钙(CN)、氯化铵（AC）5种氮肥类型，研究不同土壤类型下不同氮肥处理对小麦干物质累积、养分吸收利用和产量的影响。结果表明，小麦‘豫教5号’对氮肥类型的响应与土壤类型有关，应根据土壤类型选择不同的氮源肥料。在潮土条件下，硫酸铵和氯化铵处理有利于小麦干物质累积，显著提高小麦产量及氮肥利用效率和氮肥偏生产力；在黄褐土条件下，硝酸钙处理表现较好；砂姜黑土条件下，硝酸钙和硫酸铵处理的干物质累积量和产量较高。研究结果明确了不同土壤类型下适合小麦生长的氮肥形态，为氮肥的合理施用及小麦的高产栽培模式奠定了理论基础。 相似文献
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玉米苗期施用缓/控释氮素肥料养分释放特点与土壤生物活性研究 总被引：1，自引：1，他引：1
采用盆栽试验,模拟田间生态环境,测定施用不同种缓/控释氮素肥料,玉米苗期土壤尿素态氮、硝态氮、铵态氮含量,脲酶、硝酸还原酶活性、微生物量碳和氮含量变化趋势,比较玉米苗期氮素养分释放、土壤生物活性特点。研究表明,玉米苗期,施用SA nBPT U肥料,尿素态氮和NH4 -N的积累量最多,对土壤脲酶活性有显著的抑制作用;SA U肥料,硝态氮最多;MMA nBPT U肥料,尿素自膜内迁移到土壤中的量较少,硝态氮和微生物量最少。包膜与脲酶抑制剂nBPT相结合的缓/控释肥料,对减少硝态氮的生成效果最为明显。施用nBPT U肥料,微生物量最多。施用不同种缓/控释氮素肥料,土壤硝酸还原酶活性普遍增强,脲酶抑制剂nBPT对土壤硝酸还原酶活性无显著作用;施用不同种缓/控释氮素肥料土壤微生物量碳、氮的变化趋势一致。丙烯酸树脂包膜与脲酶抑制剂相结合的缓/控释肥料控释效果最好。 相似文献