Late Nitrogen Application Research Articles

Booting stage is the key timing for split nitrogen application in improving grain yield and quality of wheat – A global meta-analysis

Wheat is one of the most important staple crops and is mainly consumed as baked goods. Late nitrogen (N) application following a previous basic fertilization is commonly conducted to increase grain protein concentration and to improve the bread-making quality of wheat. However, the effect of late N application on the yield and quality of wheat highly varied among studies and, therefore, was questioned recently. This global meta-analysis, based on reported field experiments, aimed to clarify whether, and if so under what conditions, a late N (split from the overall N fertilization rate) application that follows an earlier N application is effective in high-protein bread-wheat production. The results showed that split N application enhanced the grain protein concentration by 5.8 %, wet gluten content by 7.9 %, and dough stability time by 10.8 %, while it decreased the grain yield of wheat by 3.5 % compared to that without split N application. However, the results varied, depending on the N application methods and environmental factors. At the fertilization level of 151–200 kg N/ha which is generally recognized as the rational N recommendation rate, split N application could increase the grain protein concentration by 6.9 %, stability time by 14.0 % and wet gluten content by 7.7 % without reducing the grain yield of wheat. More importantly, both the grain yield and quality of wheat were enhanced by split N application only when late N was applied at the booting stage. Moreover, the widely observed negative correlation between grain yield and grain protein concentration was weakened by split N application at the booting stage.

LATE SOWING AND NITROGEN APPLICATION TO OPTIMIZE CANOPY STRUCTURE AND GRAIN YIELD OF BREAD WHEAT IN A FLUCTUATING CLIMATE

Adjustment of sowing date and nitrogen (N) use help alleviate farmland contradiction under fluctuating climate in Jianghuai region of China. In this study, two wheat varieties were used to study the interactive effect between two sowing dates and two basal to topdressing ratios of N fertilizer, each treatment of eight combinations arranged in Randomized Complete Block Design (RCBD) with three replications was conducted in two consecutive growth seasons of bread wheat. As results of two years of investigation, wheat plants with an excessively delayed sowing date showed a significant reduction in flag leaf angle, flag leaf area, main stem spike length and photosynthesis rate, yet a increased basic seedling number and transpiration rate, which corresponded to a notable loss in thousand kernel weight and grain yield. An increase in the proportion of topdressed N led to an increase in flag leaf angle and leaf area index, and a lower spike number per unit and thousand kernel weight, to indicate a loss of grain yield. These findings suggest that excessively delayed sowing date and high N topdressing ratios severely affected the canopy structure and thousand kernel weight of bread wheat, and subsequently reduced grain yield. Based on membership function analysis, a sowing date of 25 October coupled with the N topdressing ratio of 7:3 (the basal to topdressing ratios of N fertilizer) was the ideal combination to optimize the wheat industry in Jianghuai region of China.

Splitting nitrogen applications improves wheat storage protein composition under low N supply

AbstractFor the baking quality of wheat flours, the composition and concentration of grain protein are crucial. It is common practice to use late nitrogen (N) application to increase grain protein concentration (GPC) and hence, improve baking quality. However, the use of N fertilizer—particularly shortly before harvest—involves environmental risks. With the suitability of GPC as a parameter for baking quality predictions being more and more questioned, there are further investigations needed considering not only the GPC but also the composition of grain protein. Gluten protein composition varies depending on genotype and environmental factors, such as weather conditions and fertilization rate. To examine whether the effect of a split N application varies under different amounts of total N supply, this study investigates the effects of split nitrogen application on grain protein concentration and composition of wheat (Triticum aestivum L. cv. JB Asano) at four different N fertilization levels (0.8; 1.0; 1.2, and 1.4 g N pot−1) in a pot experiment. The GPC was affected by both, N fertilization level and split N application. In this experiment, the minimum GPC of 13%, which is required for class A wheat varieties, was only achieved when N supply was moderate (at least 1.2 g N per pot). Considering the storage protein composition, the split N application influenced the proportion of α‐/β‐gliadins and γ‐gliadins, the alterations being inconsistent. The ratio of high molecular weight (HMW) to low molecular weight (LMW) glutenin subunits was increased by the split N application only at the lowest N fertilization level. It is concluded that splitting N fertilization into three doses and hence applying one dose of N late in the season can still be a useful approach to improve GPC as well as protein composition – especially when the total N supply is low.

15N Natural Abundance Evidences a Better Use of N Sources by Late Nitrogen Application in Bread Wheat.

This work explores whether the natural abundance of N isotopes technique could be used to understand the movement of N within the plant during vegetative and grain filling phases in wheat crop (Triticum aestivum L.) under different fertilizer management strategies. We focus on the effect of splitting the same N dose through a third late amendment at flag leaf stage (GS37) under humid Mediterranean conditions, where high spring precipitations can guarantee the incorporation of the lately applied N to the soil-plant system in an efficient way. The results are discussed in the context of agronomic parameters as N content, grain yield and quality, and show that further splitting the same N dose improves the wheat quality and induces a better nitrogen use efficiency. The nitrogen isotopic natural abundance technique shows that N remobilization is a discriminating process that leads to an impoverishment in 15N of senescent leaves and grain itself. This technique also reflects the more efficient use of N resources (fertilizer and native soil-N) when plants receive a late N amendment.

Use of an N-tester chlorophyll meter to tune a late third nitrogen application to wheat under humid Mediterranean conditions

ABSTRACTIn Northern Spain, winter wheat is usually fertilized with 180–220 kg N/ha split in two applications. To reduce this rate, a strategy was tested which comprised three nitrogen (N)-applications, the latter being tuned to the nutritional needs of the crop using a chlorophyll meter. N-fertilization experiments were performed on winter wheat (Soissons variety). Treatments consisted of three N-broadcasts of 40, 60, and either 0, 40, 60, or 80 kg N/ha respectively applied at Zadoks scale growth stages 21, 30, and 37. An over-fertilized treatment of 220 kg N/ha was included for normalization of chlorophyll-meter values. Chlorophyll-meter readings were performed at growth stage 37, before fertilization. When normalized chlorophyll-meter values were below 92%, yield and grain protein contents attained with 40+60+0 kg N/ha could be respectively enhanced with third applications of 60 or 80 kg N/ha and 40 kg N/ha.

Late nitrogen application enhances spikelet number in indica hybrid rice (Oryza sativa L.)

To increase rice yield potential, field experiments were conducted in farmers’ paddies in 2011 and 2012 to evaluate the effects of different nitrogen applications on the yield and panicle components of three typical indica hybrid rice varieties in Sichuan Province. The number of grains per panicle resulting from late nitrogen application (LA) was 12 % greater than that obtained from traditional nitrogen application (TA); this increase was the main source of improvements in yield. The number of surviving and differentiated spikelets (NSS and NDiS) resulting from LA was significantly higher than that measured under TA, especially for the Fyou498 cultivar, where the NSS and NDiS increased by 15 % and 14 %, respectively. Compared with TA, the number of degenerated secondary branches and the percentage of degenerated secondary branches (NDeSB and PDeSB) were significantly reduced by 9 % and 11 %, respectively, by LA. This is the first study to demonstrate that an increase in NSS and a decrease in NDeSB lead to yield-improving effects attributable to LA. The grain yields of different varieties ranged from 9225.6 to 9408.7 kg ha−1, the PDeSB was as high as 31 %, and the number of surviving secondary branches (NSSB) was significantly and positively correlated with NSS. These data indicate that the yield of indica hybrid rice has considerable potential for being improved, and increasing NSSB is key to increasing NSS and improving the grain yield. These improvements should be pursued so as to increase the yield of hybrid rice to ensure both food security and sustainable agricultural development.

Effect of irrigation and nitrogen fertilization on the agronomic traits and yield of irrigated rice

ABSTRACT Water and nitrogen management is essential to achieve high yield potential in irrigated agricultural systems. This study aimed to evaluate the influence of flood timing and nitrogen management on the agronomic performance of irrigated rice in tropical lowland. Two experiments were conducted in a Dystrophic Haplic Gleysol during the 2007/08 and 2008/09 crop years. The experiments were carried out using the cultivars BRS Jaçanã and Epagri 109. Flood timing combined with timing of topdressing 90 kg ha -1 N was evaluated at 15, 30, 45 and 60 days after emergence. The experiment was arranged in a split plot completely randomized design, flood timing in the plots and N application in the subplots, with six replications. Late flooding as well as late nitrogen application resulted in reduction of phytobiomass, grain quality and yield of irrigated rice. Flooding is recommended at the beginning of tillering for cultivar that shows higher initial growth, while for slower growth cultivar, ponding water can be established until mid-tillering. Early flooding increases sheath blight severity in rice stems. For improved quality and productive potential of irrigated rice, early flooding period and efficient sheath blight control is necessary.

Late nitrogen application increased protein concentration but not baking quality of wheat

AbstractLate application of nitrogen (N) fertilizers at heading or anthesis is usually performed to produce wheat (Triticum aestivum L.) with high bread‐making quality. However, increasing energy costs and ecological problems due to N losses call for efficient and simplified N fertilization strategies. This study aimed to investigate the effect of late N fertilization on grain protein quality and thus baking quality and to evaluate if similar wheat quality can be maintained without late N application. Field experiments with two winter wheat cultivars differing in quality groups were conducted. The fertilization treatments comprised a rate of 220 kg N ha−1 applied in two or three doses (referred to as split N application), and 260 kg N ha−1 applied in four doses (additional late N fertilization) with different N fertilizer types. The results show that although split N application had no effect on grain protein concentration (GPC), it affected N partitioning in the grain, increasing mainly the concentration and proportion of the glutenin fraction. As a result, baking quality was improved by split N application. Late N fertilization enhanced GPC and the relative abundance of certain high molecular weight glutenin subunits (HMW‐GS). However, it had no effect on N partitioning in the grain and did not further improve baking quality. No obvious differences were found between N fertilizer types on grain yield and quality. The N fertilization effect was more pronounced on the wheat cultivar whose baking quality was more dependent on protein concentration. In evaluating baking quality of wheat flour, gliadin and glutenin proportions were better correlated with loaf volume than the overall protein concentration.

Late nitrogen fertilization affects nitrogen remobilization in wheat

AbstractA pot experiment with wheat plants was carried out to study how late application of nitrogen (N) fertilizer affects the use of pre‐anthesis N reserves during the grain‐filling period. Increasing doses of N fertilizer were applied (0, 40, and 52 mg N plant–1), either in two amendments (growth stages GS20 and GS30, according to Zadoks scale) or in three amendments (GS20, GS30, and GS37). The experiment was arranged in a complete randomized three‐block design with 129 plants per treatment. The plants were watered daily, harvested every 2 d between anthesis and maturity, and were separated into roots, leaf sheaths, leaf blades, and ears for further N determination. Grain N concentration improved due to a late N application in GS37 by 14% (higher N dose) and by 7% (further splitting the same N‐fertilizer dose, respectively). The higher the N‐fertilizer dose applied, the greater was the amount of pre‐anthesis reserves in vegetative organs, these reserves became later available for remobilization. Although splitting the same N dose in three amendments did not increase the N reserves, these reserves were more efficiently remobilized allowing an improvement in grain N concentration. The fertilizer management did not change the temporary pattern of N accumulation in the ear, but did induce a change in the amount of N remobilized and in the contribution of each organ (root, leaf sheath, leaf blade) to this remobilization. Late N amendment allowed a greater N availability of leaf blades and ear N reserves (from 20% up to 26% and from 19% up to 22%, respectively) for remobilization towards the grain, decreasing the root contribution from 28% down to 15%, while the contribution of leaf sheaths was maintained around 35% irrespective of the N applied.

Yield Response of Uniculm Wheat (Triticum aestivum L.) to Early and Late Application of Nitrogen: Flag Leaf Development and Senescence

Nitrogen (N) supply increased flag leaf area by increasing cell number. N promoted initiation and development of floret primordia. N availability upto ear emergence affected fertile floret number more than spikelet number and increased the number of grains. Late application of nitrogen at 5 days after anthesis increased percentage nitrogen in grains, grain weight and grain number due to its effect on ability of floret to set grain. Larger number of florets and grains provided sink not only for carbon but also for nitrogen accumulation with high nitrogen availability. The accumulation of grain protein depended on the accumulation and partitioning of reduced N accumulated during the vegetative stage of growth and the relative contributions of nitrate assimilation and N redistribution during grain development in low as well as high nitrogen supply. Flag leaf of ‘Gigas’ wheat retained the ability to synthesize RuBPCO on induction of nitrate reductase by substrate supply at post anthesis stage. The reductions in proteolytic enzymes were coincident with loss of Chl, total soluble protein and nitrate reductase activity from the flag leaves.

Late nitrogen fertilization affects carbohydrate mobilization in wheat

AbstractAn experiment was carried out to determine how the late application of nitrogen (N) fertilizer affects the use of pre‐anthesis carbon reserves during the grain‐filling period of pot‐grown wheat with no water shortage. Increasing doses (equivalent to 0, 140, and 180 kg N ha–1) of N fertilizer were applied, either in two amendments (stages GS20 and GS30) or in three amendments (stages GS20, GS30, and GS37, according to Zadoks scale). The management of fertilizer by combining an increased N rate with late N application was able to stimulate canopy development, to raise photosynthetic capacity and carbohydrate accumulation during the vegetative stages, and to increase grain yield. Based on the dynamics of carbohydrate accumulation in the ear, three phases were differentiated during the grain‐filling period, whose temporary pattern remained stable regardless of the fertilizer management. The net remobilization of carbohydrates started 12 d after anthesis from the leaves and 28 d after anthesis from roots and stems. The increase of the N dose with late N application allowed on one hand a lower use of the pre‐anthesis carbon reserves in favor of greater de novo photosynthesis during the grain‐filling period, and on the other hand greater relative contribution of the leaf and ear C reserves to remobilization towards the grain. Further splitting the dose increased only the relative contribution of ear C reserves. The stem contribution seemed to be independent of N applied whereas the root contribution tended to diminish with late N application.

Aplicação tardia de nitrogênio no feijoeiro em sistema de plantio direto

A adoção de técnicas que possibilitem a maximização da eficiência do uso de nitrogênio pelo feijoeiro é de extrema importância para aumentar a produtividade e qualidade de grãos, reduzir o custo de produção e evitar contaminação ambiental. O objetivo deste trabalho foi avaliar a resposta do feijoeiro (Phaseolus vulgaris L.) à aplicação de nitrogênio em cobertura nos estádios V4 e no início do R7, em sistema de plantio direto. O delineamento experimental foi em blocos ao acaso, em esquema fatorial 2 x 4, com quatro repetições. Os tratamentos foram constituídos pela aplicação de dois níveis de N (0 e 90 kg ha-1) no estádio V4, combinados com quatro níveis de N (0, 30, 60 e 120 kg ha-1) no início do estádio R7. Quando não foi realizada adubação nitrogenada de cobertura no estádio V4, a aplicação de N no início do estádio R7 aumentou a produtividade de grãos do feijoeiro em sistema de plantio direto. A produtividade máxima de grãos foi obtida com a aplicação exclusiva de 90 kg ha-1 de N no estádio V4, sendo necessárias, para atingir o mesmo nível de produtividade, maiores doses de N quando aplicadas apenas em R7. Quando é realizada aplicação de N em V4, adubações adicionais em R7 não resultam em aumento de produtividade. A aplicação de N em cobertura no estádio V4 foi mais eficiente do que a aplicação em R7, acarretando em maior incremento na produtividade por unidade do nutriente aplicado. A aplicação de N em cobertura, nos estádios V4 e início do R7, proporcionou aumento no teor de proteína nos grãos do feijoeiro.

Decision support system for improving wheat grain quality in the Mediterranean area of Israel

The yield of dryland wheat in semi-arid and arid areas is limited by rainfall. Nitrogen application and rainfall distribution determine biomass production, soil water depletion, and grain quality. A precise base level of nitrogen fertilization is applied according to the annual rainfall, but in case of more rain, the higher biomass production would dilute the nitrogen and a low quality wheat would be harvested. On the other hand, under drought conditions, harvesting for hay or silage provides a greater income than leaving the crop for grain production. Our objective was to establish a quick and simplified decision support system (DSS) for decision making at heading. It was found that, at heading, flag leaf water concentration (FLW) and flag leaf total N concentration (FLN) data can be used to support agronomic decision making. In particular, these data can assist a decision to harvest early for hay or silage, since water stress exists and the test weight is expected to decline. In other cases these data can help to forecast the need for late nitrogen application to ensure sufficient protein levels. Our results show that the proposed DSS correctly forecasts wheat grain quality, test weight and protein content, in more than 80% of the 344 experimental plots, by monitoring flag leaves at heading. Therefore, application of the suggested simplified DSS would reduce the harvesting of shriveled grains, on the one hand, and would lead to improved grain protein, on the other hand, thus ensuring high-quality production.

Effect of late nitrogen application on rice yield, grain quality and profitability in the Senegal River valley

The effect of an additional nitrogen (N) application of 30 kg N ha −1 at booting on rice yield and grain quality was investigated with 30 farmers in the Senegal River valley during the 1997 wet season (WS) and 23 farmers during the 1998 dry season (DS). Rice yields increased significantly as a result of an extra late N application on top of two N-dressings with a total of about 120 kg N ha −1 in farmer fields. Yield gains were about 1.0 t ha −1 during the 1998 DS and about 0.4 t ha −1 during the 1997 WS. Grain quality was improved through a higher milling recovery (3% increase in both seasons) and a higher percentage of head rice (30% higher in the 1997 WS and 60% higher in the 1998 DS). Benefit to cost ratios of the third nitrogen application for farmers ranged from 2.8 in the WS to 5.4 in the DS. Sorting milled rice resulted in net additional benefits for rice millers, especially in the DS, due to a higher head rice ratio. It was concluded that a third N application can raise both yield levels and grain quality in the Senegal River valley, with potential benefits for farmers and rice millers.

NITROGEN AND POST-HARVEST YELLOWING OF BRUSSELS SPROUTS

A study was made of the effect of a late nitrogen application on post-harvest yellowing of Brussels sprouts. Application of nitrogen, whether as granular fertilizer or as a lower amount sprayed over the crop in a watery solution, increased the nitrogen concentration in the outer leaves of the sprouts, but this did not result in less post-harvest yellowing. Size of the sprouts and moment of harvest, however, strongly influenced post-harvest yellowing.

Postharvest nitrogen application effect on ovule longevity of ‘cornice’ pear trees

Low fruit set and cropping are common characteristics of ‘Cornice’ pear (Pyrus communis L.) trees in spite of a high bloom density. An experiment was conducted to study the effect of late season nitrogen (N) application on ovule longevity of this cultivar. Mature trees were given a single foliar application of 0% (control), 5%, or 10% (w/v) aqueous urea immediately after harvest. Ovule senescence was detected by fluorescence microscopy. Ovule longevity was extended and fruit set was increased by fall urea. Flower density and fruit fresh weight were not affected.

Effect of late nitrogen application on growth and nitrogen balance of two cultivars of water-stressed grain sorghum

With development of water stress during grain filling, sorghum crops lose green leaves, and nitrogen (N) is remobilised from the leaves to grain. Supplementary N application just before anthesis may reduce leaf senescence, contributing to dry matter production during grain filling and, hence, grain yield. This hypothesis was tested using 2 sorghum hybrids which were known to differ in capacity for osmotic adjustment and the ability to retain green leaves under water stress, in a rainout shelter experiment in south-east Queensland. When N was applied at depth (>70 cm) where water was available, all N applied was apparently taken up by the plants, resulting in reduced leaf senescence, particularly for leaves in the middle layer. Remobilisation of N from leaf to grain during grain filling was reduced by the supplementary N application. Both stem and leaf were the source of remobilised N which contributed about 65% of the total grain N without supplementary N application, this being reduced to about 30% with N application The hybrid with known high osmotic adjustment had greater total above-ground dry matter, particularly stem dry matter, at anthesis than the other, providing more material for translocation to fill grains. It also maintained greater leaf area during early stages of grain filling. This hybrid produced significantly higher yield (465 v. 412 g/m2) only when supplementary N was applied. Without supplementary N application, their yields were similar at about 350 g/m2. It is concluded that provided N is taken up by the sorghum plants, late N application is effective in increasing grain yield under water-limiting conditions. Cultivars, however, differed in their responses to the application.

Influence of late nitrogen application on nitrogen translocation and protein fractions of wheat genotypes differing in protein content

To investigate the influence of late nitrogen application on nitrogen translocation and protein fractions, three wheat genotypes differing in protein content were studied in pot experiments at low and high fertility regimes with late foliar nitrogen application. At high fertility, late nitrogen application increased N translocation and improved N translocation efficiency greatly, however, cultivar differences were found at low fertility. Late nitrogen application increased both leaf and chaff N translocation, and increased culm N translocation only at high fertility. Relative contributions of vegetative components to N translocation efficiency were altered by late nitrogen application. Albumins and gliadins contents at maturity were also observed. Xin Kehan No. 9, the high yielding, low grain protein content cultivar showed no change in glutenins content resulting from late nitrogen application. Glutenin content of Dongnong 7742, the high yielding, high grain protein content, decreased slightly, and Robin, high grain protein but low yielding cultivar decreased only at high fertility. Residual protein contents were significantly increased by late nitrogen application for all cultivars. It was concluded that nitrogen applied at later stage could be used efficiently only at high fertility, and most of the N translocated were used for the synthesis of residual proteins.

Competition between winter wheat and Veronica hederifolia: influence of weed density and the amount and timing of nitrogen application

SummaryThe effects at Veronica hederifolia. densities on the yield of winter wheat (Triticum aestivum L.) were studied in field trials conducted at the same location in 1992 and 1993. In 1992, nitrogen at 60 kg ha‐1 was applied at tillening followed by a further 80 kg ha‐1 at the first node of stem elongation. In 1993. four regimes of nitrogen applications were compared: a total of 140 kg ha‐1 supplied at three dales. 60 kg ha‐1 supplied at tillering, 60 kg ha‐1 Supplied al the first node of stem elongation and no nitrogen as the control. Competitive effects from V. hederifolia (ranging from 17 to 192 plants m‐22), were greatest in 1993, the year with the best early growth development of this weed. In 1993, yield losses, as described with a non‐linear model changed for each regime of fertilization. In both years, V. hederifolia decreased wheat ear number per unit area for each nitrogen treatment. This is explained hy an increase in tiller mortality and a nitrogen deficiency in wheat at the stem elongation and flowering stages. Nevertheless, with late application of nitrogen, individual grain weight increased and the effect of V. hederifolia on wheat yield loss was lowest. The results are discussed in relation to the effects on all yield components, and show the importance of choosing the rieht nitrogen fertilization for specific yield targets of wheat production when infested by weeds.

Effect of late application of nitrogen on the yield and protein content of wheat

On the Darling Downs the growth and yield of a semi-dwarf wheat (cv. Oxley) under supplementary irrigation was increased by the application of up to 400 kg/ha of nitrogen (N) at planting. Nitrogen at 50 or 100 kg/ha applied at the boot stage to supplement 100 kg/ha applied at planting increased grain yield by 459 and 478 kg/ha, respectively. However, yields were still below those where all the N was applied at planting. In contrast, supplementary N (0, 25, 50 or 100 kg/ha) at flowering or after flowering generally did not increase grain yield. One exception to this was where only 50 kg/ha was applied at planting; an additional 100 kg/ha at flowering increased grain yield by 602 kg/ha. Applied at planting, more than 200 kg/ha of N was needed to produce premium grade wheat (i.e. protein content above 11.4%). To achieve this protein content where 100 kg/ha had been applied at planting an additional 100 kg/ha was needed at the boot stage or 50 kg/ha at flowering. Applied after flowering, up to 100 kg/ha of additional N produced wheat of a protein content too low to attract a premium payment. A similar quantity of N was assimilated whether the entire N application was applied at planting or where the application was split between planting and boot or flowering. Less N was assimilated when the application was split between planting and after flowering. More N was assimilated from soil than from foliar applications at the boot stage. Soil and foliar applications were equally effective at flowering in increasing the amount of N assimilated as well as the grain protein content. However, after flowering foliar application was the more effective method. The application of N at flowering to increase the protein content of this semi-dwarf cultivar is not an attractive commercial practice. The price ratio of premium to Australian Standard White wheat in recent years (<1.071 ) is less than that needed (1.0954-1.3013) to justify splitting the N application to lift grain protein content above 11.4% at the expense of yield.