Response of pepper plants to NO3:NH4 ratio and light intensity

Pepper plants were hydroponically grown in a growth chamber with two levels of light intensity (300 and 240 w/m² ) and two N0₃:NH₄ ratios (100:0 and 80:20). Plants supplied with both N forms (80:20) under high light conditions showed a decrease of nutrient uptake and produced low plant weight and yield compared to the all NO₃ treated plants. By contrast, plants receiving both N forms (80:20) with light reduced over 25% showed a growth and yield slightly superior to plants supplied with N0₃ as sole source of N. This suggests a significant light intensity‐N form interaction that favors all NO₃ nutrition for pepper at high light intensities.     

Effect of NO3:NH4 ratio and light intensity on nitrogen partitioning in pepper plants

Pepper plants were hydroponically grown in a growth chamber with two levels of light intensity (300 and 240 w/m²) and two NO₃:NH₄ ratios (100:0 and 80:20). Plants grown with both N forms (80:20) under high light regime displayed greater concentrations of free NH₄, organic soluble N and insoluble N than NO₃, treated plants, this effect was more pronounced for stem, petioles and root. By contrast, nitrate‐ammonium fed plants with light reduced over 25% presented similar concentrations of organic N (soluble and insoluble) as compared to plants supplied with NO₃ as sole source of N, however, the amount of free NH₄ in stem and root was increased. Results indicat that NH₄ supplied at low concentration was more deletereous for pepper plants grown under high light conditions, when light was reduced, plants presented an alleviation of toxic effect of NH₄ supply. Finally, nitrogen use efficiency is related to form of N nutrition and the light supplied to crop.     

Study of various NH4+/NO3- mixtures for enhancing growth of potatoes

Two experiments were conducted to determine the effects of various NH4(+)-N/NO3(-)-N percentages on growth and mineral concentrations in potato (Solanum tuberosum L.) plants using a non-recirculating nutrient film system in a controlled environment. The first experiment included six NH4(+)-N/NO3(-)-N percentages at 0/100, 20/80, 40/60, 60/40, 80/20, and 100/0 with the same total N concentration of 4 mM. The second experiment included six NH4(+)-N/NO3(-)-N percentages at 0/100, 4/96, 8/92, 12/88, 16/84, and 20/80 again with the same total N of 4 mM. In each experiment, plants were harvested 35 days after transplanting when tubers had been initiated and started to enlarge. Dry weights of shoots, tubers, and whole plant at the harvest were increased significantly with all mixed nitrogen treatments as compared with single NH4+ or NO3- form. The enhanced growth with mixed nitrogen was greatest at 8% to 20% NH4(+)-N. Also, the concentrations and accumulation of total N in the shoots and roots were greater with mixed nitrogen than with separate NH4+ or NO3- nutrition. With NH4+ present in the solutions, the concentrations of P and Cl in the shoots were increased compared to NO3- alone, whereas the tissue concentrations of Ca and Mg were decreased. It was concluded that nitrogen fertilization provided with combined NH4+ and NO3- forms, even at small proportions of NH4+, can enhance nitrogen uptake and productivity in potato plants.     

铵态氮/硝态氮对水稻铝吸收的影响及其机制研究

选用两个水稻品种武运粳7号（耐铝品种）和扬稻6号（铝敏感品种）作为实验材料,利用水培试验,通过长期和短期处理相结合的方式研究了NH4+-N和NO3--N对水稻Al吸收的影响及其作用机制。结果表明,与NH4+-N相比,NO3--N促进了水稻对Al的吸收。而且随着NO3--N浓度的提高,水稻根中Al含量显著增加,随着NH4+-N浓度的提高,水稻根中Al含量显著降低。这些结果表明NH4+-N和NO3--N对水稻Al吸收的影响具有浓度效应。当向Al溶液添加pH缓冲剂后,NH4+-N和NO3--N对根尖Al累积的影响变小,表明NH4+-N和NO3--N处理下溶液pH的变化可能是NH4+-N和NO3--N对水稻Al吸收影响不同的一个原因。     

尿素涂层对土壤渗出液NO_3~--N和NH_4~+-N的影响

采用盆栽试验方法,研究尿素涂层后施用于水田土壤其渗出液NO3--N和NH4+-N含量的变化情况。研究结果表明:与未涂层尿素相比,施用尿素涂层可使氮素释放变得平缓,土壤渗出液中NH4+-N和NO3--N浓度明显降低,有利于水稻生长对氮素的吸收利用;在等氮量条件下,施用涂层尿素处理的土壤渗出液中的NH4+-N浓度明显低于未涂层尿素处理,且尿素用量越低这一差异越明显,而土壤渗出液中的NO3--N浓度施入土壤后前10天涂层尿素低于未涂层尿素处理,而至第18天则表现出高于未涂层尿素处理的趋势;涂层处理土壤渗出液NO3--N和NH4+-N之和大都小于未涂层处理。     

The influence of N concentration and NO3/NH4 ratio on the growth of lima and snap bean and southern field pea seedlings

Abstract

Lima and snap beans and southern field peas were cultured in a modified Hoagland's solution for 14 days with N supplied as Ca(NO₃)₂ and/or (NH₄)₂SO₄ at three N concentrations and five ratios of NO₃ to NH₄. The ratio of NO₃/NH₄, rather than the N concentrations influenced seedling growth of these vegetable legumes. Maximum seedling growth of lima bean was generally obtained with all combinations of NO₃ and NH₄. A preference for 75% NO₃ and 25% NH₄ was observed for snap bean. Southern field pea growth was reduced only when all of the N was supplied as 100% NH₄. Ammonium toxicity symptoms, lesions and severe wilting, developed with snap bean and southern field pea within 14 days when cultured with 100% NH₄. Lima bean, though reduced in growth, exhibited a tolerance to the 100% NH₄ treatment.     

Comparison of the Effects of Wet N Deposition (NH4Cl) and Dry N Deposition (NH3) on UK Moorland Species

Increases in N deposition (wet and dry) have been associated with a decline in semi-natural plant communities, adapted for growth on nutrient poor soils in the UK and Europe. The impacts of N deposition applied as either wet NH₄ ⁺ or gaseous NH₃ on vegetation (7 species) from acid moorland in SE Scotland were compared in a dose-response study. Wet N deposition at 0, 8, 16, 32, 64, 128 kg N ha^?1 y^?1 was applied as NH₄Cl, and dry deposition as gaseous NH₃ (2, 6, 20, 50, 90 µg NH₃ m^?3) under controlled conditions in open-top chambers. A strong linear dose-response relationship (p<0.05) was found between foliar N content in all seven plant species and applied NH₄?N. However, in the NH₃ treatment, only C. vulgaris and P. commune showed a significant response to increasing N additions. NH₃ was found to increase the rate of water loss in Calluna in both autumn and winter by comparison with wet deposition. For Eriophorum vaginatum, the NH₃ and NH₄ ⁺ treatments showed significant N dose response relationships for biomass. A significant increase in above ground biomass, proportional to the added N, was found for Narthecium ossifragum when N was applied as NH₃ compared to NH₄ ⁺.     

硝铵比例影响小白菜生长和叶绿素含量的原因探究

采用溶液培养试验研究了不同NO3-∶NH4+比例,分别为5.00∶0.00、3.75∶1.25、2.50∶2.50、1.25∶3.75和0.00∶5.00(mmol/L)对小白菜生长和叶绿素含量的影响及其原因。结果表明,1)与纯硝营养相比,NO3-∶NH4+为3.75∶1.25(mmol/L)时,小白菜具有最大的生物量、叶面积和叶片细胞分裂素含量;2)SPAD值、叶片可溶性蛋白质和活性铁含量均随着铵态氮比例的增加而增加;3)叶片细胞分裂素含量与叶面积、叶面积与生物量间的相关显著,相关系数(r)分别为0.97、0.95(P0.05);SPAD值与叶片可溶性蛋白质以及和活性铁含量之间的相关系数(r)分别为0.99和0.97(P0.05)。适当提高铵态氮比例可以增加小白菜叶面积可能是因提高了叶片细胞分裂素含量从而促进其扩展,进而影响生物量;提高铵态氮比例可以提高叶绿素含量,与提高了叶片蛋白质和活性铁的含量有关。     

Formation of mineral N (NH4+, NO3—) during mineralization of organic matter from coal refuse material and municipal sludge

In 1994, the 14 hectare plateau of a coal refuse bank in Landsweiler‐Reden (Southwest‐Germany) was covered with a mixture consisting of 80% (v/v) refuse materials, 10% (v/v) composted wood and 10% (v/v) of sewage sludge as part of a reclamation project. The amount of sludge dry matter applied was approximately 450 Mg ha⁻¹ to a depth of 2 m. The approximate amount of nitrogen (N) applied with the substrate was 20 Mg ha⁻¹ (total N). From April 1996 until November 1997, contents of mineral nitrogen and nitrogen mineralization were monitored down to a depth of 2 m. Nitrogen mineralization was monitored by means of a modified buried bag procedure using a retrievable cylindrical receptacle. The contents of NH₄⁺‐ and NO₃⁻‐N were largest at the beginning of the observation period, reaching a peak value of 650 kg ha⁻¹ in May 1996. Then, mineral N stabilized in 1997 at a level of 200 kg N ha⁻¹, with the soil profile below 150 cm contributing about 75% to this amount. Net nitrogen mineralization was characterized by the same depth distribution. Other than in surface horizons, mineralization activity at the bottom of the profile continued into 1997 with the same intensity as in 1996. Variability among replicate buried bag incubations was high (CV > 100% on several occasions). Nitrogen loss through leaching was estimated at 630 kg N ha⁻¹ over the observation period, averaging at 360 kg N ha⁻¹ a⁻¹. The reclamation procedure used in this study may have the potential to contaminate ground water in hydrologically sensitive areas.     

The Maturity and CH4, N2O,NH3 Emissions from Vermicomposting with Agricultural Waste

This study investigated the maturity and gaseous emissions from vermicomposing with agricultural waste. A vermicomposting treatment (inoculated Eisenia fetida) was conducted over a 50-day period, taking tomato stems as the processing object and using cow dung as the nutrient substrate. A thermophilic composting treatment without earthworm inoculation was operated as a control treatment. During the experiment, maturity indexes such as temperature, pH, C/N ratio, and germination index (GI) were determined and continuous measurements of earthworm biomass and CH₄, N₂O, and NH₃ emissions were carried out. The results showed that the temperature during vermicomposting was suitable for earthworm survival, and the earthworm biomass increased from 10.0 to 63.1 kg m^?3. Vermicomposting took less time on average to reach the compost maturity standard (GI 80%), and reached a higher GI (132%) in the compost product compared with the thermophilic composting treatment. Moreover, the decrease of the C/N ratio in vermicompost indicated stabilization of the waste. The activities of earthworms played a positive role in reducing gaseous emissions in vermicompost, resulting in less emissions of NH₃ (12.3% NH₃-N of initial nitrogen) and total greenhouse gases (8.1 kg CO₂-eq/t DM) than those from thermophilic compost (24.9% NH₃-N of initial nitrogen, 22.8 kg CO₂-eq/t DM). Therefore, it can be concluded that vermicomposting can shorten the period required to reach compost maturity, can obtain better maturity compost, and at the same time reduce gaseous emissions. As an added advantage, the earthworms after processing could have commercial uses.     

长期地膜覆盖对棕壤剖面中NH_4~+-N和NO_3~--N动态变化的影响

棕壤长期定位试验结果表明,覆膜使表层土壤中NH4+-N含量明显增加,并使各个层次NO3--N含量都有所增加,有效地减少了NO3--N的淋失。研究同时表明施用有机肥和化肥都能提高土壤全氮、碱解氮、NH4+-N、NO3--N含量,而施用单一的氮肥则对土壤碱解氮几乎没有影响。因此,有机肥与无机肥配合施用是培肥覆膜土壤氮素肥力的有效措施。     

不同硝铵比氮素供应对广藿香生长及药效成分的影响

【目的】探讨不同硝铵比氮素营养对广藿香生长、产量、生理效应、挥发油及药效成分的影响,为提高广藿香的产量和药用品质提供氮肥施用依据。【方法】以海南藿香为研究材料进行了砂培盆栽试验。设5个不同NO₃–-N/NH₄+-N比处理为100∶0、75∶25、50∶50、25∶75、0∶100,每隔10天浇一次,每次250 mL/盆,每盆定植1株6 cm高的广藿香组培苗。采收期分为定植后60、120、180、240天,每个处理每次采取4盆,分析了广藿香生长指标、叶绿素、抗氧化活性及药效成分。【结果】硝铵比为75∶25的处理更能促进广藿香的株高、茎粗、分蘖数、叶面积指数、地上部鲜重、地上部干重、茎含油率、叶含油率、全株含油率和单株含油量增加,也有利于叶绿素a和叶绿素a + b含量提高。硝铵比为75∶25处理的广藿香植株N、P、K、Ca、Mg元素吸收最多,硝铵比为25∶75和0∶100处理的较低。硝铵比为50∶50的处理有利于叶绿素b含量和苯丙氨酸解氨酶 (PAL酶) 活性的提高,有助于广藿香茎叶的广藿香酮的提高。硝铵比为25∶75和50∶50的处理更有利于羟自由基、超氧阴离子自由基、DPPH自由基清除率的提高。硝铵比25∶75处理有利于广藿香茎叶广藿香醇和其他主要药效成分含量的提高。全硝态氮和全铵态氮 (硝铵比为100∶0和0∶100) 处理不利于或抑制广藿香茎叶油的药效成分形成和积累。【结论】供应硝铵比为75∶25的氮更能促进广藿香生长和光合效能的提高,硝铵比为50∶50、25∶75处理更能促进广藿香主要药效成分含量的提高。     

铵硝比例对不同基因型小白菜硝酸盐积累影响机理研究

本研究以前期工作中筛选出的硝酸盐积累量存在显著差异的2个不同基因型小白菜品种为材料,在人工气候箱水培条件下研究了不同铵硝比例对小白菜硝酸盐积累量、硝酸还原酶活性（NRA）和硝酸盐吸收基因NRT1和NRT2的表达量的影响。结果表明,不同铵硝比例对小白菜硝酸盐积累量有显著影响,且存在基因型差异。四月慢对硝酸盐吸收、积累及同化利用的能力都强于华冠青梗菜,尤其是在高NO3- 比例处理时。与华冠青梗菜相比,四月慢对NO3- 的同化利用的能力更不易受铵硝比例的影响。NRT1和NRT2主要在根部表达,且NRT1的表达量显著高于NRT2,NRT1和NRT2的表达量变化规律只能在一定程度上解释小白菜不同基因型间硝酸盐积累量的差异,小白菜不同基因型品种间硝酸盐积累量差异的机理还需要进一步研究。     

A Laboratory Study of the Interaction of NH3 and NO2 with Sea Salt Particles

It is known from the literature that the reaction 2 NO₂(aq) + Cl-(aq) → NO₃-(aq) + ClNO(g) takes place in the presence of NO₂ and sea salt aerosol. This work indicates that the reaction is first order in Cl- and second order in NO₂(aq) and the rate coefficient was determined to be 8.9 ± 2.1) × 10¹⁰ M-² s-¹ at 293 K. The study shows that the formation rate of nitrate in liquid sea salt aerosol is not influenced by pH in the range between 5.1 and 7.5. The uptake of ammonia in liquid sea salt particles in the present experimental system is governed by the rate of the reaction CO₂(aq) + H₂O → H₂CO₃. The addition of NH₃ to NO₂ and dry sea salt particles does not change the extent of nitrate formation in the particles. The dry aerosol shows an unexpected content of ammonium which increases with decreasing relative humidity. The nitrate formation in frozen sea salt particles at 266 K exposed to only NO₂, is about 5 times lower than for the corresponding droplets at 293 K.     

Einfluß der NO3- bzw. NH4-Ernährung auf Ertrag und Nitratgehalt von Spinat und Kopfsalat

Influence of NO₃ and NH₄-nutrition on yield and nitrate content of spinach and lettuce Field and pot experiments were conducted in order to study the effect of N-supply (N_min + N-fertilization) and partial and complete NH₄-nutrition on yield and nitrate content of spinach and lettuce. The highest yields were obtained when the N-supply of spring spinach was 250 kg N/ha, autumn spinach 200 kg N/ha and lettuce 120 kg N/ha. Nitrate content of plants could be diminished by reducing N-supply. However, if N-supply is below the optimum value yield depressions are inevitable. NH₄-nutrition reduced in both species nitrate content. But, spinach yield was reduced heavily. Very low nitrate content of plants occured, when N-nutrition of plants cultivated in nutrient solution, was changed from NO₃ to NH₄ during the last days before harvest. Herewith similar weights and head quality were obtained as with permanent NO₃-nutrition.     

植物镍营养

本文主要论述了镍对植物生长的必需性和土壤镍的植物有效性.现已证明,镍是高等植物的必需微量元素.它作为脲酶的金属辅基参与氮代谢,从而对高等植物生命周期的完成是必不可少的.土壤平均镍含量为5～50mg/kg,其形态包括水溶态、交换态、吸附态和矿物态.其中对植物有效的包括水溶态、交换态和部分吸附态镍.镍的植物有效性受土壤pH、质地和土壤有机质等影响.     

N2O, NO, and NH3 Emissions from Soil after the Application of Organic Fertilizers, Urea and Water

Agricultural soil is a major source of nitrous oxide (N₂O), nitric oxide (NO) and ammonia (NH₃). Little information is available on emissions of these gases from soils amended with organic fertilizers at different soil water contents. N₂O, NO and NH₃ emissions were measured in large-scale incubations of a fresh sandy loam soil and amended with four organic fertilizers, [poultry litter (PL), composted plant residues (CP), sewage sludge pellets (SP) and cattle farm yard manure (CM)], urea fertilizer (UA) or a zero-N control (ZR) for 38 days. Fertilizers were added to soil at 40, 60 or 80% water-filled pore space (WFPS). The results showed that urea and organic fertilizer were important sources of N₂O and NO. Total N₂O and NO emissions from UA ranged from 0.04 to 0.62%, and 0.23 to 1.55% of applied N, respectively. Total N₂O and NO emissions from organic fertilizer treatments ranged from 0.01 to 1.65%, and <0.01 to=" 0.55%=" of=" applied=" n,=" respectively.=" the=" lower=">₂O and NO emissions from CP and CM suggested that applying N is these forms could be a useful mitigation option. Comparison of the NO-N/N₂O-N ratio suggested that nitrification was more dominant in UA whereas denitrification was more dominant in the organic fertilizer treatments. Most N was lost from PL and UA as NH₃, and this was not influenced significantly by WFPS. Emissions of NH₃ from UA and PL ranged from 62.4 to 69.6%, and 3.17 to 6.11% of applied N, respectively.     

NO3-和NH4+对水稻和旱稻生长及水分利用的影响

用分根法研究NO3-和NH4 对水稻‘越富’和旱稻‘297’生长和水分利用的影响,结果表明:与水稻相比,旱稻在NO3-中的生长最好。NH4 提高氮素在水稻根中的分配比率,同时也提高了水稻和旱稻根系在NO3-/NH4 处理中NH4 一侧的吸氮速率。旱稻水分利用率高于水稻,且二者的水分利用率都遵循NH4 >NH4NO3≥NO3-的规律。     

N2O,NO, and NH3 Emissions from Soil after the Application of Organic Fertilizers,Urea and Water

Water, Air, & Soil Pollution - Agricultural soil is a major source of nitrous oxide (N2O), nitric oxide (NO) and ammonia (NH3). Little information is available on emissions of these gases from...