Nitrogen Accumulation In Grain Research Articles

Breeding progress of nitrogen use efficiency of cereal crops, winter oilseed rape and peas in long-term variety trials.

Grain yield and NUE increased over time while nitrogen yield did not drop significantly despite reduced nitrogen input. Selection for grain and nitrogen yield is equivalent to selection for NUE. Breeding and registration of improved varieties with high yield, processing quality, disease resistance and nitrogen use efficiency (NUE) are of utmost importance for sustainable crop production to minimize adverse environmental impact and contribute to food security. Based on long-term variety trials of cereals, winter oilseed rape and grain peas tested across a wide range of environmental conditions in Germany, we quantified long-term breeding progress for NUE and related traits. We estimated the genotypic, environmental and genotype-by-environment interaction variation and correlation between traits and derived heritability coefficients. Nitrogen fertilizer application was considerably reduced between 1995 and 2021 in the range of 5.4% for winter wheat and 28.9% for spring wheat while for spring barley it was increased by 20.9%. Despite the apparent nitrogen reduction for most crops, grain yield (GYLD) and nitrogen accumulation in grain (NYLD) was increased or did not significantly decrease. NUE for GYLD increased significantly for all crops between 12.8% and 35.2% and for NYLD between 8% and 20.7%. We further showed that the genotypic rank of varieties for GYLD and NYLD was about equivalent to the genotypic rank of the corresponding traits of NUE, if all varieties in a trial were treated with the same nitrogen rate. Heritability of nitrogen yield was about the same as that of grain yield, suggesting that nitrogen yield should be considered as an additional criterion for variety testing to increase NUE and reduce negative environmental impact.

Optimizing the Growth Conditions of the Selected Plant-Growth-Promoting Rhizobacteria Paenibacillus sp. MVY-024 for Industrial Scale Production.

Simple SummaryNitrogen is one of the most important elements for plant growth and development. However, irrational fertilization causes many environmental problems: high rates of nitrogen fertilizers change the soil pH, encourage nitrate and nitrite accumulation in plants and the soil, leached nitrogen compounds cause water eutrophication and drinking water contamination, and gaseous losses of nitrogen contribute to global warming. The biological nitrogen fixation (BNF) process, in which atmospheric nitrogen is converted to ammonia by microorganisms, has a significant role in the global nitrogen cycle and agriculture. Nitrogen-fixing-bacteria inoculants could help to reduce the losses of consistently rising prices of mineral fertilizers and help to implement green revolution strategies. In this research, we found the bacteria strain Paenibacillus sp. MVY-024 that has a positive impact on nitrogen accumulation in spring wheat and was easily applied on an industrial scale.In this study, thirteen isolates, which were possibly expected to fix nitrogen, were isolated from soil and pea root nodules and identified by the gene analysis of 16S rDNA sequences. Two of these isolates that were able to form endospores and grow on nitrogen-free media were selected for spring wheat development research. The isolate Paenibacillus sp. S7 identified as Paenibacillus polymyxa was found to significantly increase the amount of ammonium and mineral N amounts in the soil. Furthermore, increased nitrogen accumulation in grains and a chlorophyll index were obtained after wheat treatment. Paenibacillus sp. S7 isolate was selected for further studies and the accession number MT900581 and strain name MVY-024 in NCBI nucleotide bank for this isolate were assigned. During the cultivation of Paenibacillus sp. MVY-024, sugarcane molasses and a yeast extract were determined as the most suitable carbon and nitrogen sources, whose optimal concentrations were 100 g L−1 and 10 g L−1, respectively. The optimal pH range for the cell culture was between 6.5 and 7.0, and the optimal air flow rate was 0.4 vvm. It was found that the air flow has an effect on biomass production and endospore formation. After Paenibacillus sp. MVY-024 biomass cultivation optimization, the cultured cell number was, on average, 2.2 × 109 cfu m L−1.

Variation in nitrogen accumulation in grain and leaf in spring barley genotypes

AbstractRequirements of barley grain protein concentration vary depending on the end‐use purpose of the grain. High protein levels are desired for high‐quality feed and food, whereas relatively low protein levels are preferred for malting. The current study evaluated variation of grain protein concentration and nitrogen (N) concentration in flag leaves among barley genotypes with diverse backgrounds. A panel of 79 spring barley genotypes was grown in field experiments under well‐watered and drought‐stressed conditions over two growing seasons. In each water regime, variation in flag leaf N concentration (only under drought‐stressed conditions), grain protein concentration, grain yield and other agronomic parameters was found among genotypes. Based on grain protein and flag leaf N concentration, four broad genotype categories were found: high values for both, low values for both, low grain protein with high flag leaf N and high grain protein with low flag leaf N. This grouping suggests variation in N remobilization from vegetative tissues to grain. Germplasm identified in the present study will enable further study of the mechanisms regulating protein accumulation in barley and contribute to the development of barley germplasm for various end uses.

Optimized Planting Density Maintains High Wheat Yield Under Limiting Irrigation in North China Plain

Regulating plant density is an important practice to improve winter wheat productivity under limited irrigation in North China Plain. Field experiments were carried out over two seasons (2014–15 and 2015–16) under three plant densities (Dh: 480–570, Dm: 360–390, Dl: 240–270 104 plants hm−2) and three irrigation levels (W0: no irrigation; W1: irrigated 80.0 mm only at the jointing stage, which also means limited irrigation; W2: irrigated 60.0 mm each at the jointing and the flowering stages). Results showed that higher numbers of spikes and higher yield were obtained at high density than that at low density under limited irrigation. Under the same irrigation, wheat culms at ripening stage and the proportion of main stem spikes increased with plant density increasing, along with the increasing of transportation amount, transportation rate, and contribution rate of pre-anthesis storage material to grain. But accumulation amount and contribution rate of post-anthesis dry matter, which was influenced by irrigation level, showed a declining trend with increasing plant density under W2 and W1. Therefore, (1) under limited water condition, yield loss could be compensated by increasing contribution rate of pre-anthesis storage material to grain with increasing plant density. (2) Meantime, under the same limited water condition, higher plant densities could promote nitrogen accumulation in grain and plant of wheat, which was significantly correlation to wheat yield. (3) Considering water and nitrogen use efficiency, medium plant density (Dm) is recommended in wet years, high plant density (Dh) may be considered to increase wheat yield in dry years.

Nitrogen accumulation in grains, remobilization and post-anthesis uptake under tan spot and leaf rust infections on wheat

Nitrogen (N) fluxes involve important processes determining grain yield and quality in wheat (Triticum aestivum L.) and could be affected by major fungal diseases like leaf rust (Puccinia triticina Eriks) and tan spot [Pyrenophora tritici-repentis (Died.) Drechs., anamorph Drechslera tritici-repentis) (Died.) Shoem.]. Although effects of foliar diseases on N accumulation and translocation have already been studied, none of these studies performed inoculations in field conditions. This study aimed to determine the effects of independent inoculations to ensure the predominance of each pathogen of 1) Pyrenophora tritici-repentis (necrotroph) and 2) Puccinia triticina (biotroph) on N accumulation and allocation in wheat crops. Experiments were carried out using a split-split plot design where the main plots were both diseases, subplots were three inoculation treatments and ten cultivars were the sub-subplots. Healthy area duration (HAD), crop growth rate (CGR), N remobilization (NREM), N post-anthesis uptake (NPU), %N in grains and N stored in grains were calculated. The results indicate that the nutrition habit of the pathogens would cause a differential effect on crop N fluxes with more noticeable effects for P.triticina, explained by the retention of N in green tissues, which prevents the normal translocation of N to the grains. Higher rates of N stored in grains, NREM and a negative rate for % N in grains were manifested due to longer extensions in the HAD for leaf rust compared to tan spot. Inoculations with Py.tritici-repentis caused increases in the %N in grains up to 14.9%, while P.triticina reduced it by 9.89%. Both NREM (-30.9%) and N stored in grains (-24.4%) showed significant reductions under increases in the inoculum dose of P.triticina, but not under Py.tritici-repentis infections. Relating HAD and CGR to N accumulation under foliar diseases infections could be an effective tool to improve the modelling of yield and quality losses more accurately.

Impact of tillage practices on nitrogen accumulation and translocation in wheat and soil nitrate-nitrogen leaching in drylands

Although the effects of tillage practices on soil properties and root growth is well studied, how they affect nitrogen accumulation and translocation in wheat in dryland regions is poorly understood. Here, the impact of different tillage practices, namely, strip rotary tillage (SR), strip rotary tillage after subsoiling (SRS), rotary tillage (R), and rotary tillage after subsoiling (RS), on nitrogen accumulation and translocation, grain yield, and economic benefit in wheat and soil nitrate-nitrogen leaching in drylands was studied over three wheat growing seasons from 2009 to 2012. The results showed that compared with R, nitrogen accumulation amount under SRS increased by 36.8% from jointing to maturity in 2009–2011 and by 12.9 and 16.4% from sowing to maturity in 2009–2010 and 2010–2011, respectively. Post-anthesis nitrogen accumulation, its contribution rate to grain and nitrogen accumulation in grains at maturity under SRS were 48.3, 31.3 and 12.7% higher, respectively, compared to that under R in 2009–2010. On the other hand, nitrate-nitrogen accumulation under SRS in 0–60cm soil layers was lower in comparison to that under SR and R, which suggested that SRS promoted absorption of nitrate-nitrogen in soil layers by wheat. However, no significant difference in nitrate-nitrogen accumulation in the 60–200cm soil layers was observed between SR and R. Average grain yield, nitrogen production efficiency and economic benefit were all the highest under SRS at 598.78gm−2, 39.9kgkg−1 and 8350.8 RMB¥ha−1, respectively, over the study period. Therefore, we propose that SRS is the optimal tillage practice for wheat production in this region.

The effects of free-air CO₂ enrichment (FACE) on carbon and nitrogen accumulation in grains of rice (Oryza sativa L.).

Rising atmospheric CO2 concentrations will probably increase rice (Oryza sativa L.) yield but decrease grain nitrogen (GN) concentration. Grains attached to different positions in the panicles differ greatly in weight and quality, but their responses to elevated CO2 (e[CO2]) are poorly understood, which limits our understanding of the mechanisms of yield enhancement and quality degradation. Thus a free-air CO2 enrichment experiment was conducted to examine the effects of e[CO2] on grain mass (GM), grain carbon (GC), and GN accumulation in the spikelets attached to the upper primary rachis branch (superior spikelets; SS) and those attached to the lower secondary rachis (inferior spikelets; IS). e[CO2] stimulated the rice yield by 13% but decreased the N concentration in the panicle by 7% when averaged over two levels of N fertilizations (P < 0.01). The responses of SS and IS to e[CO2] were different particularly under higher N supply. For SS, e[CO2] decreased GN by 24% (P < 0.01) but did not affect GM. For IS, e[CO2] increased GM by 13% (P < 0.05) but GN was not affected. The reduction of GN due to e[CO2] started to appear at the beginning of grain filling. These results suggest that future [CO2] levels probably stimulate the grain growth of IS, most of which are not marketable due to limited size, at the expense of GN reduction in SS. Translocation of N from SS to IS may be a possible mechanism for reduction in GN of SS. This may degrade the grain quality of marketable rice under e[CO2].

Impact of Genotype and Nitrogen Fertilizer Rate on Yieldand Nitrogen Use by Oat (Avena sativa L.) in Turkey

Efficient nitrogen (N) use is one of the most crucial issues for crop management in developing countries. Since Turkish agricultural practices tends to use lower inputs of N fertilizers, a field trial was carried out in 2007-08 and 2008-09 cropping years to determine response of six oat genotypes (Seydisehir, Apak, Yesilkoy-330, Amasya, Checota and Yesilkoy-1779) to three N rates (0, 100 and 200 kg ha -1 ). According to the results, differences between the years were significantly important for all investigated traits except soil nitrogen content at planting (NCP), nitrogen content at maturity (NCM) and nitrogen accumulation in grain (NAG). Genotypes significantly varied for all traits except NCP, nitrogen in grain (NG) and NAG. However, differences among N rates were significant for all traits except NCP.Among the genotypes Checota had the highest nitrogen use efficiency (NUE) and grain yield (GY) (20.6 kg kg -1 N and 2590 kg ha -1 , respectively).

NEMA, a functional-structural model of nitrogen economy within wheat culms after flowering. II. Evaluation and sensitivity analysis.

Simulating nitrogen economy in crop plants requires formalizing the interactions between soil nitrogen availability, root nitrogen acquisition, distribution between vegetative organs and remobilization towards grains. This study evaluates and analyses the functional-structural and mechanistic model of nitrogen economy, NEMA (Nitrogen Economy Model within plant Architecture), developed for winter wheat (Triticum aestivum) after flowering. NEMA was calibrated for field plants under three nitrogen fertilization treatments at flowering. Model behaviour was investigated and sensitivity to parameter values was analysed. Nitrogen content of all photosynthetic organs and in particular nitrogen vertical distribution along the stem and remobilization patterns in response to fertilization were simulated accurately by the model, from Rubisco turnover modulated by light intercepted by the organ and a mobile nitrogen pool. This pool proved to be a reliable indicator of plant nitrogen status, allowing efficient regulation of nitrogen acquisition by roots, remobilization from vegetative organs and accumulation in grains in response to nitrogen treatments. In our simulations, root capacity to import carbon, rather than carbon availability, limited nitrogen acquisition and ultimately nitrogen accumulation in grains, while Rubisco turnover intensity mostly affected dry matter accumulation in grains. NEMA enabled interpretation of several key patterns usually observed in field conditions and the identification of plausible processes limiting for grain yield, protein content and root nitrogen acquisition that could be targets for plant breeding; however, further understanding requires more mechanistic formalization of carbon metabolism. Its strong physiological basis and its realistic behaviour support its use to gain insights into nitrogen economy after flowering.

Effect of magnesium or zinc supplementation at the background of nitrogen rate on nitrogen management by maize canopy cultivated in monoculture

In five consecutive growth seasons from 2003 to 2007 a response of maize variety Eurostar (var. FAO 240) to supply of NPK fertilizer supplemented with magnesium or zinc was investigated. The aim of the study was to evaluate the role of zinc (NPK + Zn) or magnesium (NPK + Mg) in controlling nitrogen management by maize crop fertilized with 80 and 140 kg N/ha. In the course of the study, total grain nitrogen content did not show any response to both experimental factors and weather variability, as well. However, the obtained results indicate, that magnesium and zinc have significantly increased SPAD (chlorophyll index) indices of maize cob leaf at anthesis. A significant effect of both factors interaction on nitrogen accumulation in grain and cob covering leaves was noted, but limited to the 80 kg N/ha treatment. The physiological role of Mg and Zn in nitrogen management was most manifested throughout its greater recovery from nitrogen fertilizer applied at the rate 80 kg N/ha, amounting to 92 and 94% respectively; for the NPK, it was only 78%.

Effects of Irrigation Amount on Nitrogen Uptake, Distribution, Use, and Grain Yield and Quality in Wheat

以济麦20和泰山23为试验材料,在大田条件下研究了灌水量对小麦氮素吸收、分配、利用和籽粒产量与品质及耗水量、水分利用率的影响。2004—2005年生长季,小麦生育期间降水量为196.10mm,两品种的氮素吸收效率、籽粒的氮素积累量和氮肥生产效率均为不灌水处理低于灌水处理,但籽粒氮素分配比例和氮素利用效率表现为不灌水处理高于灌水处理。拔节期前,两品种的氮素吸收强度灌水180mm处理高于灌水240mm和300mm两处理,拔节期后反之;成熟期,植株氮素积累量和氮素吸收效率在各灌水处理间无显著差异。济麦20籽粒的氮素积累量和分配比例、氮素利用效率和氮肥生产效率,均以灌水240mm处理高于灌水180mm和300mm处理;灌水180mm和240mm处理的籽粒产量分别达8701.23kghm^-2和9159.30kghm^-2,耗水量为469.29mm和534.48mm,两处理间籽粒品质无显著差异,且均优于灌水300mm处理。泰山23籽粒中氮素积累量及分配比例、氮素利用效率、氮肥生产效率和籽粒品质,在各灌水处理间无显著差异;灌水180mm和240mm处理籽粒产量显著高于其他处理,分别达9682.65kghm^-2和9698.55kghm^-2,其耗水量分别为468.54mm和532.35mm。两品种的水分利用率均随灌水量增加而降低。在2006—2007年生长季,小麦生育期间降水量为171.30mm,济麦20和泰山23均以灌水240mm处理的籽粒产量和水分利用率最高,其耗水量分别为490.88mm和474.88mm。综合考虑产量、品质、氮素利用效率、氮肥生产效率和水分利用率,生产中济麦20生育期灌水量以180-240mm为宜;泰山23在降水量达196mm条件下,灌水量以180mm为宜,在降水量为170mm条件下,灌水量以240mm为宜。

Light-associated nitrogen distribution profile in flowering canopies of sunflower (Helianthus annuus L.) altered during grain growth.

In vegetative canopies of many species, the vertical gradient of lamina nitrogen concentration (NW) parallels the profile of light distribution in such a way that the actual nitrogen partitioning approaches the optimum pattern for canopy photosynthesis. This paper evaluates the hypothesis that a strong sink for nitrogen, viz. growing grain, affects the pattern of lamina nitrogen distribution usually described for vegetative canopies. The light and NW profiles of sunflower (Helianthus annuus L.) crops were characterised from anthesis to physiological maturity. The factorial combination of two plant populations (2.4 and 4.8 plants m-2) and two levels of nitrogen supply (0 and 5 g N m-2) were the sources of variation for NW and light profiles. Before the onset of nitrogen accumulation in grain, the pattern of NW was similar to that described for other species and it was related to the distribution of light in the canopy. Important changes in the profile of NW occurred during grain filling that were unrelated to the light regime. Nitrogen was mobilised from leaves in all positions in the canopy and the rate of NW change was greater in leaves closer to the grain, which were also the leaves where nitrogen was more concentrated. It is concluded that the physiological mechanisms involved in determining the distribution of leaf nitrogen in vegetative canopies do not apply to sunflower during grain filling.

Effect of foliar sprayings of urea during or after anthesis on dry matter and nitrogen accumulation in the grain of two wheat cultivars ofT. aestivum L.

The objective of this work was to determine the effect of foliar urea spraying during or after anthesis, on dry matter and nitrogen accumulation in the wheat grain of two cultivars, differing in grain protein content. The experiment was carried out in the field, and 20 kg N ha−1 as urea (46-0-0) was sprayed at anthesis, 7 or 14 days after anthesis. Dry weight, N content and N percentage of the grain were determined at several stages of its development.

Dry matter and nitrogen accumulation in grains at different ear positions in ‘gigas’, semidwarf and normal spring wheats

Distribution and accumulation of dry matter (d.m.) and nitrogen (N) were investigated within ears of a semidwarf, a gigas, and a normal wheat genotype grown under controlled environments. A high harvest index was linked with a small pre-anthesis N-storage (and vice versa) but this did not affect N amounts in grains because of compensation by prolonged N uptake during grain filling. N distribution within and between spikelets roughly paralleled that of d.m. Nevertheless, the two processes appeared to be rather independent as became evident from comparisons of the time courses in and between the genotypes. Final distribution of d.m. and N within and between spikelets mainly depended on different rates during the linear phases of accumulation and less on the duration. Maximum of d.m. and N weights per grain as well as maximum of grain number were observed in spikelets below the middle of the ear axis. This ‘submedian dominance’ suggested a pre-anthesis determination of the accumulation potential of grains in different spikelets. N percentage within spikelets disclosed that N accumulation was hampered more than that of d.m. in those positions unfavourable to the latter process. This principal pattern was not affected by genotypes in spite of considerable differences in numbers and weights of grains.

Correlative Analysis of Yield and its Components in Maize

SUMMARYAt Pantnagar, India, linear response in maize to nitrogen application was observed up to 150 kg. of N/ha. with some of the most promising hybrids and composites released by the All India Co-ordinated Maize Improvement Programme. Increase in grain yield, and total nitrogen accumulation in grain, were substantially more in Ganga 2 than in the local cultivar or the composites, at higher rates of N application. In absolute terms, the local cultivar accumulated more nitrogen in its grain, but the relative amounts declined at higher rates of N application. Among the yield components influencing ultimate grain yield, barrenness exerted a negative influence on grain yield through the number of cobs per plot. Among cob characters, such as thousand grain weight and number of grains per cob, the former exerted a substantial influence on grain yield.