腐植酸对番茄苗期氮素代谢的影响

腐植酸对肥料具有改性增效的作用,以番茄为供试材料,研究腐植酸增效剂不同添加量对番茄苗期生长及氮素代谢酶活性的影响,为腐植酸的开发应用提供参考依据。采用砂培试验方法,设置了向霍格兰营养液分别加入腐植酸增效剂0(HA0),1(HA1),2(HA2),5(HA3),10(HA4) mL/L处理。培养30天后,测定番茄的生长指标、植株养分含量、硝酸还原酶活性、谷氨酰胺合成酶和谷氨酸脱氢酶活性。添加适量腐植酸增效剂能促进番茄苗期生长,HA3处理番茄根系干重比HA0提高了31.68%,HA1处理番茄地上部干重最大。添加腐植酸可以提高番茄苗期叶片叶绿素含量,HA3处理番茄苗期叶片叶绿素总量和类胡萝卜素含量最高,分别比HA0提高了17.11%,24.04%。添加适量腐植酸增效剂能增加番茄苗期根系和地上部对氮素的吸收,HA3处理的番茄根系、地上部及总氮素积累量比HA0分别提高了30.61%,20.24%,21.54%。添加腐植酸增效剂可以调控番茄根系和叶片氮素代谢过程,提高了氮素代谢酶活性,与HA0相比,HA4处理根系硝酸还原酶活性最大,HA3处理根系谷氨酰胺合成酶活性最高,HA2处理根系谷氨酸脱氢酶的活性最大;HA3处理番茄苗期叶片中硝酸还原酶、谷氨酰胺合成酶和谷氨酸脱氢酶活性最大,与HA0处理相比分别提高了38.27%,64.54%,106.63%。添加腐植酸增效剂可以促进番茄苗期的生长和对氮素的吸收,提高氮素代谢酶活性,处理中以在营养液中添加5 mL/L腐植酸增效剂效果最佳,腐植酸增效剂添加量低于5 mL/L时,对番茄苗期的生长及氮素代谢具有明显的促进作用。     

Fruit Yield of Tomato Cultivated on Media with Bicarbonate and Nitrate/Ammonium as the Nitrogen Source

ABSTRACT

This article presents the effects of nitrate/ammonium (NO₃ ^?/NH₄ ⁺), applied at different proportions to the root media with or without 5 mmol bicarbonate (HCO₃ ^?), on the yield and chemical composition of tomato fruit. Tomato plants were grown hydroponically (pH 6.9) in glasshouse conditions. The yield of fruit fresh matter from four clusters obtained from plants grown on the medium with NH₄ ⁺ was about 25% lower than from the plants grown on the medium containing NO₃ ^? as the nitrogen (N) source. Supplying NO₃ ^?/NH₄ ⁺ at a ratio of 4:1 increased the fruit yield by about 20% in comparison with the value recorded for NO₃ ^??plants. The enrichment of the medium with HCO₃ ^? stimulated the bearing, while the result depended on the ratio of NO₃ ^?/NH₄ ⁺. A combined treatment of HCO₃ ^? with NO₃ ^? or NH₄ ⁺ in the medium increased yields by about 28% and 11%, respectively, in comparison to plants cultivated without HCO₃ ^?. The application of NO₃ ^?/NH₄ ⁺ at ratios of 4:1 and 1:1 with HCO₃ ^? increased the respective yields by about 16% and 10% in comparison with plants grown without HCO₃ ^?. Modifications in the composition of the media affected the accumulation of organic solutions in the fruit. The NH₄ ⁺ nutrition effected a 20% decrease in the accumulation of reducing sugars in the fruit in comparison to the fruit of plants grown in media with NO₃ ^?. In the cultivation of plants in media with various NO₃ ^?/NH₄ ⁺ proportions the intermediate values of the reduced sugar concentrations were recorded in comparison with the values obtained for NO₃ ^??plants and NH₄ ⁺?plants. The enrichment of media with HCO₃ ^? increased the concentration of sugars in fruit from about 28% (for NO₃ ^??plants) to about 10% (for NH₄ ⁺?plants).

Malate and citrate are the main constituents of carboxylates in tomato fruit. The form of nitrogen applied to the medium did not significantly affect the concentration of carboxylates in fruit. Significant differences in carboxylate concentrations appeared in fruit grown on media enriched with HCO₃ ^? ions. In comparison with the cultivation without HCO₃ ^?, increases in the accumulation of carboxylates varied from about 22% to 30% depending on the form of the applied nitrogen. The concentration of amino acids in the fruit of plants grown with NH₄ ⁺ exceeded that in NO₃ ^??plants by about 55%. In the plants grown on media of modified NO₃ ^?/NH₄ ⁺ proportions, the concentration of amino acids in fruits were positively correlated with the level of NH₄ ⁺ in the medium. The enrichment of media with HCO₃ ^? stimulated a further increase in amino acid concentration in fruit by about 9% in NO₃ ^? plants and about 21% in NH₄ ⁺ plants compared with the respective control (without HCO₃ ^?).     

Corn Monoculture Yield Response to Fertilization and Nitrate Nitrogen Distribution

The objectives of this study were to determine the effects of fertilization system, nitrate (NO₃)– nitrogen (N) distribution along soil profile, and their interaction on corn yield. The study was conducted at the experimental field of Institute of Field and Vegetable Crops in Novi Sad (Serbia) during 2001–2004. Corn monoculture included four fertilization variants: control (Ø), nitrogen–phosphorus–potassium (NPK) mineral fertilizers, mineral fertilizer + corn stalks (NPK + S), and mineral fertilizers + manure (NPK + M). The greatest yield was found in the variant NPK + M (9.25 t ha^?1). Path coefficients showed that greatest direct positive effects on corn yield were exhibited by NO₃-N levels at soil depths of 60–90 cm and 30–60 cm. The path analysis showed that winter precipitation (WP) had a direct negative effect on yield performance. However, the effect of the downward movement of NO₃-N from the topsoil to deeper soil layers of WP on yield was positive.     

盐碱胁迫对甜菜氮代谢相关酶活性及产量和含糖率的影响

利用KWS0143和ACERO为试验材料,比较盐碱(碳酸钠)胁迫对2个甜菜品种氮代谢关键酶活性及产量和含糖率的影响,旨在进一步明确甜菜对盐碱胁迫的适应性。通过桶栽试验,设5个处理,分别是碳酸钠占土壤质量百分比0、0.5%、1%、1.5%和2%,对应的土壤溶液p H值分别为7.14、8.92、9.45、10.19、10.56。研究盐碱胁迫对甜菜叶片硝酸还原酶(NR)、谷氨酰胺合成酶(GS)、谷氨酸合酶(GOGAT)活性及产量和含糖率的影响。结果表明,盐碱胁迫使甜菜叶片的硝酸还原酶(NR)、谷氨酰胺合成酶(GS)及谷氨酸合酶(GOGAT)活性均下降,且随着盐碱胁迫程度的增大,下降幅度增大。两品种比较,ACERO的酶活性高于KWS0143,且ACREO的块根产量和含糖率下降的幅度低于KWS0143,ACREO比KWS0143具有较强的耐盐碱能力。该研究为进一步提高盐碱胁迫下甜菜对氮素的吸收利用效率理论依据。     

Nitrate Dynamic in a Tropical Mollisol Amended with Organic Manures,Planted with Sweet Corn,and Monitored with SPAD Readings

Two field experiments were conducted to evaluate the use of relative chlorophyll content (RCC) in sweet corn leaves as an indicator of nitrate concentration in soil. Study objectives were (1) to evaluate the effect of manure types (chicken and dairy), rates (0, 168, 336, and 672 kg ha^?1 equivalent N), and application frequency (one and two applications) of organic amendments on (a) nitrate nitrogen (NO₃-N) concentration within and below the crop root zone and (b) the RCC of sweet corn leaves and (2) to quantify the relationship between RCC and NO₃-N concentrations. The results showed a significant increase in NO₃-N concentrations within and below the root zone and plant leaf RCC under chicken manure treatments. Manure application rates and frequency had a significant effect on both NO₃-N concentration within and below the root zone and leaf RCC. It appears that leaf RCC can be used as an indicator of NO₃-N availability for sweet corn cultivated under the study conditions.     

春玉米产量、氮肥效率及土壤矿质氮对施氮的响应

为了提高氮肥增产效益,减少对环境的污染,通过田间试验研究了施氮量对春玉米产量、氮肥效率及土壤矿质氮的影响。结果表明,施氮量较低时,春玉米籽粒产量随施氮量增加显著增加,当施氮量高于180 kg·hm-2时,产量保持不变或有减少趋势。氮肥农学利用率、氮素吸收效率、氮素偏生产力和氮收获指数均随着施氮量增加显著降低,氮肥表观利用率和氮肥生理利用率均先增加后降低。从苗期到收获期,施氮处理0~60 cm土层硝态氮含量呈现"上升—下降—上升—下降—稳定"的变化趋势,而60~120 cm土层硝态氮在春玉米生长后期有增加的趋势。随着土层加深,土壤硝态氮含量呈波浪式下降,施氮量240 kg·hm-2和300 kg·hm-2处理在60~100 cm土层硝态氮含量均显著高于其他处理。随着施氮量增加,0~120 cm土层硝态氮累积量显著增加,当施氮量超过240kg·hm-2时,土层中累积的硝态氮存在着较大的淋溶风险。综合考虑产量、氮肥效率和环境效应,179~209 kg N·hm-2是本试验条件下春玉米的合理施氮量。     

硝酸还原酶基因启动子NRE2元件缺失对烟草氮代谢的影响

为了探究硝酸还原酶基因启动子中硝酸盐响应元件NRE2缺失对烟草植株氮代谢的影响,以烤烟品种K326为材料,采用CRISPR/Cas9基因编辑技术获得了烟草NIA11和NIA2基因启动子中NRE2元件缺失的突变体材料,并于同一氮素营养条件下培养,测定烟草植株氮代谢相关生理指标.结果表明,与野生型相比,单突变体和双突变体叶...     

Effects of Molybdenum,Nickel, and Nitrogen Sources on the Mineral Nutrition and Growth of Rice Plants

Upland rice plants, cultivar ‘IAC 202,’ were grown in nutrient solution until full tillering. Treatments consisted of ammonium nitrate (AN) or urea (UR) as nitrogen (N) source plus molybdenum (Mo) and/or nickel (Ni): AN + Mo + Ni, AN + Mo ? Ni, AN ? Mo + Ni, UR + Mo + Ni, UR + Mo ? Ni, and UR ? Mo + Ni. The experiment was carried out to better understand the effect of these treatments on dry‐matter yield, chlorophyll, net photosynthesis rate, nitrate (NO₃ ^?‐N), total N, in vitro activities of urease and nitrate reductase (NR), and Mo and Ni concentrations. In UR‐grown plants, Mo and Ni addition increased yield of dry matter. Regardless of the N source, chlorophyll concentration and net photosynthesis rate were reduced when Mo or Ni were omitted, although not always significantly. The omission of either Mo or Ni led to a decrease in urease activity, independent of N source. Nitrate reductase activity increased in nutrient solutions without Mo, although NO₃ ^?‐N increased. There was not a consistent variation in total N concentration. Molybdenum and Ni concentration in roots and shoots were influenced by their supply in the nutrient solution. Molybdenum concentration was not influenced by N sources, whereas Ni content in both root and shoots was greater in ammonium nitrate–grown plants. In conclusion, it can be hypothesized that there is a relationship between Mo and Ni acting on photosynthesis, although is an indirect one. This is the first evidence for a beneficial effect of Mo and Ni interaction on plant growth.     

Response of Young Citrus Trees on Selected Rootstocks to Nitrogen,Phosphorus, and Potassium Fertilization

The majority of the citriculture in Brazil is located in the state of São Paulo, with a total production area of 700,000 ha. Trees are grafted mostly on ‘Rangpur’ lime (RL; Citrus limonia Osbeck) rootstock. Despite its good horticultural performance, use of other rootstocks has increased with the search for disease-tolerant varieties to improve grove productivity and longevity. Furthermore, there is a lack of information on young tree response to fertilization, and optimal nutrient requirements of different scion/rootstock combinations for maximum fruit yield. A network of field experiments was conducted to study the differential response of young sweet orange trees on selected rootstocks to nitrogen (N), phosphorus (P), and potassium (K) fertilization. The application of soil and leaf analyses to develop optimal fertilizer recommendations was evaluated. Experiments were conducted in three locations using fractional factorial design of one-half (4 × 4 × 4) type with four rates of N, P, or K calculated to be applied for five years after tree planting. Fruit yield response was evaluated during the last two years and correlated with soil and leaf analyses data. The trees on RL rootstock demonstrated increased efficiency of nutrient use and fruit production compared with those on ‘Cleopatra’ mandarin (CL; C. reshni hort. ex Tanaka) or ‘Swingle’ citrumelo [SW; Poncirus trifoliata (L.) Raf. × C. × paradisi Macfad.] rootstocks. The trees on SW rootstock appeared to require greater N and K rates than those on RL rootstock. Phosphorus requirement was greater for ‘Natal’ or ‘Valencia’ trees on CL than on RL rootstock. These results will become the basis for revising current fertilizer recommendation guidelines for young trees in Brazil.     

Analysis of Yield Response Variability to Nitrogen Fertilization in Experiments Performed in the Argentine Pampas

Abstract

Nitrogen (N) fertilization has become a common practice in corn and wheat crops in the Argentine Pampas during the past decade. In this region, great environmental variability determines erratic responses to fertilization. The quantity of data necessary for defining yield response models to N has not been investigated, and the relative yield transformation, combined with the total nutrient approach, has been widespread when analyzing fertilizer response results. The objectives were to determine the minimum data set necessary for fitting average yield functions suitable for fertilizer recommendation at regional scale and to investigate the consequences of using relative yield on N response functions when the total nutrient approach is used. Published results from two extensive fertilization networks, one with corn and the other with wheat, were used. Data were aggregated at different levels, because one single experiment to the entire network results, and yield response functions to N were fitted. Yield models tended to stability when a set of around 100 or more data points, generated in experiments performed across different sites and years, were used for fitting models with both crops. This amount of data was generated by performing 20 experiments in the corn network and 35 in the wheat network. Relative yield transformation allowed us to obtain models with lower dispersion than yield, but in the case of corn a biased model was generated that leads to underestimating fertilizer requirements. In wheat, similar fertilizer recommendations were produced from yield or relative yield functions. Response variability to fertilization must be addressed in the experimental area by increasing the amount of data used, rather than by applying the relative yield transformation.     

Spatial Variability of Corn Yield and Yield Response to Fertilizer Nitrogen: Role of Organic Carbon

Utility of organic carbon (OC) content as an indicator of corn (Zea maize L.) grain yield and yield response to nitrogen (N) across a broad range of conditions was assessed using data from two studies (the first on a variable landscape at Elora Research Station and the second on 19 landscapes in private farms) conducted from 1998 to 2003 in southern Ontario. Zero and 140/150 kg N ha^?1 were applied in all studies. Yields generally increased linearly or quadratically with increasing OC. Regression models indicated 42% of the data sets had no response to fertilizer N and in only two data sets in Elora and no data sets in private farms were yield responses to N dependent on OC. When yield increased with fertilizer addition, it was similar for all OC contents in a landscape. We concluded that OC content cannot be used to identify N-management units in southern Ontario.     

Maize (Zea mays L.) Grain Yield Response to Methods of Nitrogen Fertilization

ABSTRACT

In the developing world, fertilizer application is commonly achieved by broadcasting nutrients to the soil surface without incorporation. A commonly used nitrogen (N) source is urea and if not incorporated, can sustain N losses via ammonia volatilization and lower crop yields. This study evaluated the effect of planting, N rate and application methods on maize (Zea mays L.) grain yield. An experiment with a randomized complete block design (nine treatments and three replications) was established in 2013 and 2018 in Oklahoma. The planting methods included; farmer practice (FP), Oklahoma State University hand planter (OSU-HP), and John Deere (JD) mechanical planter. Side-dress N application methods included; dribble surface band (DSB), broadcast (BR), and OSU-HP. Nitrogen was applied at the rate of 30 and 60 kg ha^?1 as urea and UAN at V8 growth stage. On average, planting and applying N at 60 kg ha^?1 using OSU-HP resulted in the highest yield (11.4 Mg ha^?1). This exceeded check plot yield (5.59 Mg ha^?1) by 104%. Nitrogen application improved grain yield by over 57% when compared to the 0-N check (8.77 Mg ha^?1). Mid-season N placement below the soil surface using OSU-HP makes it a suitable alternative to improve grain yield.     

水分调节剂DY-ET100对番茄产量、品质及水氮在土壤中扩散的影响

为解决水分在土壤中横向扩散范围小和硝态氮淋溶等问题,以水分调节剂DY-ET100为供试材料,以清水、渴以友为对照,研究和对比了水分调节剂DY-ET100的添加对水分在不同土壤中的扩散情况及对硝态氮淋溶和番茄产量及品质的影响。结果表明,在掺沙和未掺沙黏土中添加水分调节剂DY-ET100较清水处理番茄果实中VC含量分别显著提高12.50%和20.51%;添加DY-ET100的处理使距滴头0～30 cm范围内的水分在土壤中分布更加均匀,滴灌时水分扩散半径较清水和渴以友分别增加22.53%和12.33%;在掺沙和未掺沙黏土中较清水处理硝态氮累积量增加41.21%和18.83%;同时减少硝态氮的淋溶损失量,在掺沙和未掺沙黏土较清水处理硝态氮淋溶损失降低7.53%和8.07%。研究为水分调节剂的使用推广提供了数据支撑。     

包膜肥对设施番茄产量及土壤氮、磷累积的影响

采用小区试验方法研究包膜肥对设施番茄产量及土壤N、P累积的影响,结果表明:施用包膜肥处理与传统处理相比,在中期50d时提高了表层(0-30cm)土壤中氮的含量,而对60-120cm土层的影响不明显,对磷的影响在表层和地下都不明显。在种植结束时(110d),包膜肥处理在0-120cm的土层中都显著降低了氮的含量,在0-30cm中提高了磷的含量,但在30-120cm的土层中没有显著影响。相同施肥量时,在110d时包膜肥处理降低了N、P在30cm以下土层中的累积,同时包膜肥可显著提高番茄产量;在包膜肥追肥量较传统处理减少1/3时,产量依然没有显著降低。包膜肥处理较传统处理也降低了番茄硝酸盐的累积。     

长期定位施肥对土壤有机质和碱解氮及冬小麦产量的影响

22年肥料长期定位试验结果表明,施用有机肥和化肥能够显著改善土壤有机质含量,施用有机肥处理效果比无机肥更为显著。在施用有机肥处理中,高肥处理比低肥处理效果更为显著;在施用无机肥处理中,以NPK配合施用效果更为明显,高氮处理与低氮处理相比,二者差异并不显著。长期定位施肥对碱解氮的影响与有机质基本一致。此外,长期定位施肥对冬小麦产量的影响与有机质和碱解氮吻合。     

Different Response of Grain Yield to Soil Organic Carbon,Nitrogen, and Phosphorus in Red Soil as Based on the Long-Term Fertilization Experiment

Eurasian Soil Science - Soil organic carbon (SOC), total nitrogen (TN), and total phosphorus (TP) are essential nutrients for plant growth. Thus, soil amendments that increase the amounts of these...     

氮磷钾硫的施用对冬小麦光合特性及产量的影响

试验于河南农业大学科教示范团区进行，以强筋小麦豫麦34为试验材料，研究了氮磷钾硫对小麦光合特性及籽粒产量的影响。结果表明，在本试验范围内，氮磷硫肥用量对强筋小麦群体光合速率、叶绿素含量和硝酸还原酶活性均具有明显的调节作用，各因子不同供给水平对光合特性指标的影响均表现为随施用量的增加而提高，但于花后不同时期处于主导地位的肥料因子有所不同。氮磷钾硫配施对籽粒产量也有明显的调节作用，硫氮对产量的影响达到极显著水平，是影响冬小麦产量的最大因子，而磷肥、钾肥对产量影响不显著，N70P120K180S30是最佳水平组合。     

Response of Upland Rice Genotypes to Nitrogen Fertilization

Nitrogen (N) is one of the most yield-limiting nutrients for upland rice production in Brazilian Oxisol soils. A field experiment was conducted for two consecutive years at the National Rice and Bean Research Centers Experimental Station Capivara with the objective to evaluate 10 promising genotypes of upland rice for N-use efficiency. The N rates used were 0 kg ha^?1 (low) and 100 kg ha^?1 (high). Plant height, shoot dry weight, grain yield, panicle number, and 1000-grain weight were significantly influenced by N and genotype treatments. Nitrogen × genotype interactions were not significant for most of the growth, yield, and yield components, indicating that differences among genotypes were consistent across N rates. Based on grain yield efficiency index (GYEI), genotypes were classified as N efficient or inefficient. Among 10 genotypes, four genotypes were efficient and six were moderately efficient in N use in the first year. In the second year, three genotypes were efficient and seven were moderately efficient in N use. Genotype BRA 052015 was classified as efficient in N use in both the years. Grain harvest index and GYEI had significant linear relationships with grain yield.     

Effect of Foliar Nitrogen Application on Nitrogen Metabolism,Water Status,and Plant Growth in Two Maize Cultivars under Short-term Moderate Stress

Two contrasting maize (Zea mays L.) cultivars, i.e. ‘Shaandan 9’ (S₉) and ‘Shaandan 911’(S₉₁₁) were investigated by examining foliar nitrogen (N) modulation of N metabolism, water status and plant growth under short-term moderate water stress (SMWS). On 10th day of SMWS, dry matter (DM), relative water content (RWC) and nitrate reductase activity (NRA) were significantly decreased, whereas concentrations of free proline (FP), glycinebetaine (GB) and soluble protein (SP) were increased in leaves of both cultivars. Cultivar S₉ maintained greater DM, RWC and these N metabolism traits than S₉₁₁ during SMWS. Foliar N application much more raised DM, RWC, NRA, and concentrations of all solutes measured under SMWS above control. These positive effects were more pronounced in S₉₁₁ than those in S₉ during SMWS. Greater correlations were performed amongst all parameters under SMWS than control. Hence, we suggest that foliar N should be firstly applied to drought sensitive cultivars under drought.     

Nitrogen uptake efficiency of finger millet grown in hydroponic culture

The optimum nitrogen requirement along with nitrogen uptake efficiency of finger millet (Eleusine coracana) for obtaining plants of a high phenotypic quality was studied in this research using hydroponic culture. 20 days old seedlings were transferred in nutrient solution containing all the essential macro and micro nutrients. Plants were subjected to three treatments of nitrate viz. 0.05 mM, 0.1 mM and 0.5 mM by dissolving it in the nutrient solution. Plants grown in nutrient solution devoid of nitrate were treated as control. Plants grown in 0.5 mM nitrate conc. attained more height compared to other low nitrogen treatments (0.1 mM and 0.05 mM). Similarly plants of 0.5 mM nitrate treatments possessed more number of lateral roots, surface area of leaves, dry weight of plants and chlorophyll content compared to other low nitrogen treatments. Specific activity of nitrate reductase in plants treated with 0.5 mM concentration was found nearly 3 times higher than that of control plants; similarly, specific activity of nitrite reductase in 0.5 mM treated plants was also high compared to other low nitrogen treatments followed by control. The results of the present investigation therefore indicate that nitrogen uptake efficiency as revealed by the activities of nitrate reductase and nitrite reductase was high in 0.5 mM nitrate treatment. It also shows that 0.5 mM nitrate is optimum nitrogen concentration for the growth of finger millet in hydroponic condition.