Nitrogen Grain Research Articles

IMPACT OF BIO-ORGANIC FERTILIZATION AND NITROGEN LEVELS ON MAIZE (Zea mays L.) RESILIENCE

A field study on maize growth in sandy soils found that applying 5 tons/fad of compost significantly enhanced plant growth and grain yield. Increasing the nitrogen (N) rate up to 135 kg N/fad also, led to a notable increase in plant and grain yield and resulted in early flowering. The application of phosphorus and potassium (PK) at a rate of 15.5 kg P2O5 + 48 kg K2O/fad led to early flowering and significantly increased grain yield. Furthermore, the application of PK fertilizer led to an increase in the nitrogen and phosphorus content of grains in both growing seasons. The concentration of proline, which serves as an endogenous osmoprotectant against biotic stress, also increased. The suggested PK fertilizer level (15.5 kg P2O5 + 48 kg K2O/fad) resulted in a notable rise in the CP% in grains. The research further revealed that the uptake of nitrogen in grains increased in response to higher nitrogen levels, with the maximum nitrogen utilization efficiency being 25.11 kg of grains/ kilogram of applied nitrogen.

Response of maize grown in calcareous soils to levels of agricultur-al sulfur, thiobacillus bacteria and nano-zinc

A field experiment was conducted in spring season of 2022 according to a randomized complete block design with three replications (RCBD). The experiment included three factors. The first included three levels of agricultural sulfur (0, 1500, and 3000 kg ha-1). The second factor included two levels of thiobacillus bacteria, which are the control treatment (no addition) and the treatment with bacteria. The third factor included three concentrations of nano-zinc (0, 50, and 100 mg L-1). The results showed an excellent level of sulfur (3000 kg ha-1) in the grain yield (8.06 Mg ha-1), the percentage of nitrogen in the grains (1.72%), the percentage of phosphorus in the grains (0.53%) and the percentage of protein in grains is (10.79%), and the percentage of sulfur in grains is (0.270%). As the results showed that the second factor was superior when adding thiobacillus bacteria in the weight of 500 grains and the total grain yield (154.64 g and 7.52 Mg ha-1, respectively). As for nano-zinc, the third level (100 mg L-1) excelled in percentage of nitrogen (1.62%), phosphorus (0.41%), protein (10.79%) and sulfur (0.239%) in Grains, and the weight of 500 grains (155.53 g), with the exception of the total yield characteristic in which the level excelled (50 mg L-1) with an average of (8.01 mg L-1). The interaction between the three factors also gave a positive effect on most of the traits under study.

Impact of Application Methods and Doses of Micronutrients on Wheat’ Grain Yield, Nutrient Content and Their Uptake

Various methodologies (soil or foliar application) and doses of zinc (Zn), iron (Fe) and manganese (Mn) either in conjunction with urea or in combination with one another were used to evaluate grain and straw production as well as nutrient concentration and their uptake in wheat. The experiment's findings showed that adding Zn, Fe and Mn significantly enhanced grain and straw production over control as well as available nitrogen (N), phosphorus (P) and potassium (K) content and their uptake. When 2.5 mg Zn kg-1 + 5 mg Fe kg-1 + 5 mg Mn kg-1 + 30 mg N kg-1 was applied, the maximum grain yield, straw yield, P uptake in grain and straw, as well as K concentration and uptake in grain and straw were found. Highest N content both in grain and straw was observed when 0.5% FeSO4 + 3 % Urea were applied. Phosphorus content in grain was recorded highest when 0.5% MnSO4 + 0.5% Citric acid was applied whereas in straw maximum concentration of phosphorus was noticed when 0.5% ZnSO4 + 2% Urea were applied. Highest uptake of nitrogen in grain was found when 0.5% MnSO4 + 2.5% Urea were applied and in straw when 0.5% FeSO4 + 3 % Urea were applied. The experimental results also showed that micronutrient (Zn, Fe and Mn) concentration and uptake significantly increased as compared to control with micronutrient application (Zn, Fe and Mn).

Effect of Biofertilizers on Nutrient Uptake by Green Gram [Vigna radiata (L.) Wilczek] under Agri-horti System in Vindhyan Region of Eastern Uttar Pradesh

A field investigation was carried out in Factorial Randomized Block Design during autumn 2018 at agricultural farm, Rajiv Gandhi South Campus, Barkachha, Mirzapur (RGSC), Banaras Hindu University (U.P.) to investigate the impact of fertiliser and biofertilizer on the nutrient uptake by the green gram (V. radiata L.) plant and grain under guava (P. guvajava L.) trees. The twelve year old guava orchard was established in August 2006 with spacing of 7m x 7m. Seven fertilizer combination viz., control, Rhizobium culture, press mud, phosphorus solubilizing bacteria, Rhizobium culture + fertilizer, phosphorus solubilizing bacteria + fertilizer and press mud + fertilizer were applied. Among them application of press mud + fertilizer performed better by recording highest nitrogen content in grain (3.75), nitrogen content in grain (1.50), removal of nitrogen in grain (33.09) Removal of nitrogen in straw (33.03) and phosphorus content in grain (0.41) phosphorus content in straw (0.30), phosphorus uptake in grain (3.62), phosphorus uptake in straw (5.61), and found significantly superior to rest of the treatments.

Nitrogen Use Efficiency of Quality Protein Maize (Zea mays L.) Genotypes

Use of more nutrient-use efficient Quality Protein Maize (QPM) varieties will likely play a pivotal role in maintaining or increasing crop yields and nutritional values in fields where soils are degraded. This study aimed to: (i) assess the nitrogen use efficiency (NUE) of different QPM inbred lines at various levels of nitrogen (N) fertilizer application; (ii) determine the relationships among NUE indices and yield; and (iii) determine the appropriate rate of fertilizer application for QPM genotypes under conditions of this study. Thirty-two QPM inbred lines were evaluated at 0, 30, 60, 90 and 120 kg N ha−1 N fertilizer application in a split-plot randomized complete block design with two replicates at the University of Fort Hare Crop Research farm, South Africa. Results revealed highly significant differences (p ≤ 0.001) for total nitrogen in biomass (Bio Total N), total nitrogen in grain (G Total N), grain yield, NUE and almost all the indices estimated across N levels. The top three genotypes which showed high-yielding potential at 30 kg N ha−1 include L2 (6.24 t/ha), L3 (6.47 t/ha) and L4 (6.34 t/ha), and were considered the most N-efficient genotypes under low N soils. The highest grain yields (6.74 t/ha) and highest NUtE (Nitrogen Utilization Efficiency) (1.93 kg grain/total N) were obtained at 90 kg N ha−1. Highly significant and positive correlation coefficients were found between NUE and yield (+0.9), NUE and NUtE (+0.9), NUE and HI (Harvest Index) (+0.5), NUtE and yield (+0.99), HI and yield (+0.5) and NUtE and HI (+0.5). Highest nitrogen uptake efficiency (NUpE) was obtained from the lowest fertilizer rate, which was 30 kg N ha−1.

Dense Planting with Reducing Nitrogen Rate Increased Nitrogen Use Efficiency and Translocated Nitrogen in Grains in Double-Cropped Rice

Nitrogen fertilization and planting density are two key factors that influence the yield of rice. Reducing nitrogen fertilizer input and increasing planting density will help to improve nitrogen use efficiency and stabilize yield. Field and 15N tracer method in plot experiments were conducted to study the trends of yield, nitrogen use efficiency (NUE) and nitrogen transfer of hybrid rice and conventional rice under dense planting with a reduced nitrogen rate (DPRN) and sparse planting with a high nitrogen rate (SPHN). Among the nitrogen in rice plants, the proportion of nitrogen from fertilizer under the DPRN was reduced by 1.8–13%. The late-season rice (LSR) had a higher rate of decrease compared with the early-season rice (ESR). The uptake efficiency of nitrogen fertilizer was significantly higher under the DPRN than that under the SPHN, with an increase of 7.7–21.9%. The accumulated nitrogen and translocated ratio under the DPRN before the heading stage were 6.1–10.8% and 2.0–9.6% higher than those under the SPHN, respectively. The yield did not change under different treatments. Those findings suggest that the DPRN could guarantee a stabilized yield while increasing the NUE and the amount of translocated nitrogen in the double-cropped rice system.

Indigenous organic resources utilization, application methods and sowing time replenish soil nitrogen and increase maize yield and total dry biomass

Wise management of indigenous resources replenishes soil nutrients and improves crop productivity and soil sustainability. Three year consecutive experiments were performed in the framework of Farmers Field School (FFS) during 2012–2014. Organic nitrogen sources [animal-urine (AU), animal-manures (AM), and animal manure-compost (AMC) with two application methods [interior-application method (IAM) and exterior-application method (EAM)] and three sowing timing [early sowing (ES), late-sowing (LS), and timely sowing (TS)] were studied. One control plot in each replication was placed as a check. The results showed that among different sowing time, TS has higher grains year−1, 1000 grains weight, dry biomass, grain yield and harvest index (HI) than LS and ES. AM delayed silking and physiological maturation. A higher grains year−1, 1000 grains weight, grain yield, total dry biomass, and HI were observed with AMC than control plots. In application methods, the IAM has delayed the silking and physiological maturity as compared to EAM. Similarly, higher grains year−1, 1000 grains weight, grain yield, dry biomass, and HI were observed with IAM than EAM. In sowing timing, higher grain nitrogen (GN) was observed in TS. Higher GN produced by AMC and AU treated plots. AMC produced 10% higher GN than manures treated plots. The IAM produced higher GN than EAM. The AMC produced significantly higher soil N and statistically at par with AU treated plots. IAM applied AMC, maize grain yield was higher than the AU and AM. In conclusion, AMC and AU embedded in soil with TS can sustainably increase maize yield and soil productivity.

Influence of Tillage Practices and Nitrogen Sources on Nitrogen Availability and Uptake of Rice

Aim: Evaluation of tillage practices and nitrogen sources on nitrogen availability in soil and nitrogen uptake of rice
 Study design: The experiment was laid out in strip-plot design with different tillage practices in horizontal strip and different nitrogen sources in vertical strip and was replicated thrice.
 Place and duration of study: The field experiment was conducted during the kharif season of 2019 and 2020 at the Agricultural College Farm, Bapatla, ANGRAU, Lam, Guntur, Andhra Pradesh.
 Methodology: The experiment was performed with twenty treatments in strip-plot design. The horizontal strip comprised four different tillage practices and vertical strip with five different nitrogen sources. Rice variety “BPT-5204” was taken as the test variety. Observations of the crop and soil during the experimentation were recorded at regular intervals. The significance of the treatment impact was examined by the test.
 Results: Among tillage practices, higher nitrogen uptake by rice grain (85.30 and 86.96 Kg ha-1) and straw (41.21 and 41.91 Kg ha-1) during 2019-20 and 2020-21, respectively was recorded in conventional tillage (T4) which was found statistically on a par with dry seeding on puddled soil (T1) (81.15 and 82.79 Kg ha-1, 38.59 and 39.20 Kg ha-1 during 2019-20 and 2020-21, respectively) and significantly superior over reduced tillage (T2) and minimum tillage (T3). Among nitrogen source, application of 50% STBN through fertilizer + 50% N through cured poultry manure (N5) registered the highest uptake of nitrogen in grain and straw (85.38 and 87.02 Kg ha-1. 42.09 and 42.76 Kg ha-1 during 2019-20 and 2020-21, respectively) and it was found significantly on a par with 75% STBN through fertilizer + 25% N through cured poultry manure (N4) and significantly superior over 50% STBN through fertilizer + 50% N through FYM (N3), 75% STBN through fertilizer + 25% N through FYM (N2), and 100% STBN through fertilizer (N1) treatment.

A critical review of the impacts of cover crops on nitrogen leaching, net greenhouse gas balance and crop productivity.

Cover crops play an increasingly important role in improving soil quality, reducing agricultural inputs and improving environmental sustainability. The main objectives of this critical global review and systematic analysis were to assess cover crop practices in the context of their impacts on nitrogen leaching, net greenhouse gas balances (NGHGB) and crop productivity. Only studies that investigated the impacts of cover crops and measured one or a combination of nitrogen leaching, soil organic carbon (SOC), nitrous oxide (N2O), grain yield and nitrogen in grain of primary crop, and had a control treatment were included in the analysis. Long‐term studies were uncommon, with most data coming from studies lasting 2–3 years. The literature search resulted in 106 studies carried out at 372 sites and covering different countries, climatic zones and management. Our analysis demonstrates that cover crops significantly (p < 0.001) decreased N leaching and significantly (p < 0.001) increased SOC sequestration without having significant (p > 0.05) effects on direct N2O emissions. Cover crops could mitigate the NGHGB by 2.06 ± 2.10 Mg CO2‐eq ha−1 year−1. One of the potential disadvantages of cover crops identified was the reduction in grain yield of the primary crop by ≈4%, compared to the control treatment. This drawback could be avoided by selecting mixed cover crops with a range of legumes and non‐legumes, which increased the yield by ≈13%. These advantages of cover crops justify their widespread adoption. However, management practices in relation to cover crops will need to be adapted to specific soil, management and regional climatic conditions.

Effect of nitrogen concentrations and Fusarium oxysporum inoculation on barley growth under different Cd levels

Nitrogen fertilization plays an essential role in plant-defense reactions against various stresses. However, its role in developing a plant's heavy-metal stress reaction in the presence of fungal inoculation is still not well understood. Therefore, a greenhouse pot experiment of barley plants was carried out to trace the impact of different concentrations of nitrogen (60 and 90 mg kg−1) and inoculation with Fusarium oxysporium on the nitrogen uptake and the yield/plant, which were affected by various cadmium levels in the soil using the 15N tracer technique. The dry weight increased significantly with increasing N concentrations and cadmium concentrations in the spiked soil, especially for fungal inoculated plants compared to than uninoculated plants. The highest N uptake was detected in the shoots and grains of fungal inoculated plants with different nitrogen levels. The cadmium content in grains tended to decrease with fungal inoculation. This holds true for all nitrogen and cadmium interactions compared to the uninoculated plants. On the other hand, cadmium detention was recorded in the roots of fungal inoculated plants that were fertilized with highest N-concentrations. The highest percentage of nitrogen in grains derived from fertilizer (Ndff%) was 24.45 and 23.30% in the pots with 90 mg N/kg soil + 10 mg Cd/kg soil + Fungi and 90 mg N/kg soil + 20 mg Cd/kg soil + Fungi, respectively, while the nitrogen use efficiency (NUE%) of the grains in the these pots were recorded as 4.3% and 4.2%, respectively.

Response of Different Wheat (Triticum Aestivum L.) Varieties to Graded Levels of Nitrogen

The present study entitled, “Response of different wheat (Triticum aestivum L.) varieties to graded levels of nitrogen” was conducted during winter season, 2009-10 on sandy clay loam soils of Students’ farm, College of Agriculture, Acharya N. G. Ranga Agricultural University, Rajendranagar, Hyderabad. The treatments consisted of three varieties (HP 4080, RAJ 4037 and HI 8682) and four nitrogen levels (0, 60, 120 and 180 kg N ha). The experiment was laid out in randomized block design with varieties as first factor and nitrogen levels as second factor with three replications. Plant height, tillers m, leaf area index and dry matter at 10, 30, 60, 90 days after sowing and at harvest were recorded maximum with variety RAJ 4037. Similarly, at 180 kg N ha plant height, tiller m, leaf area index and dry matter were found markedly higher compared to the rest of the doses. The physiological studies have indicated that crop growth rate was maximum between 60-90 DAS and maximum for variety RAJ 4037 and at 180 kg N ha among all the levels of nitrogen. Relative growth rate and net assimilation rates were found maximum between 10-30 days after sowing. Yield attributing characters i.e., number of ears m, spike length and 1000-grain weight were maximum with variety RAJ 4037. All the above yield attributing parameters were found maximum with 180 kg N ha. Grain and straw yield recorded maximum with variety RAJ 4037 over the other two varieties and among the nitrogen levels application of 180 kg N ha` recorded maximum grain and straw yields. Among the post harvest observations apparent recovery fraction, protein content were maximum with the variety RAJ 4037. Physiological efficiency was more with variety HP 4080. Agronomic efficiency was found to be on par with all the three varieties and all the nitrogen levels. Protein content was maximum with 180 kg N ha. Apparent recovery fraction was maximum with 60 kg N ha and physiological efficiency with 120 kg N ha. The nitrogen uptake in grain and straw was maximum with variety RAJ 4037. Among the nitrogen levels, 180 kg N ha recorded significantly maximum uptake of nitrogen in grain and straw. Net returns and benefit-cost ratio were maximum with variety RAJ 4037 and among the nitrogen levels application of 180 kg N ha recorded maximum values. It can be concluded that among the three varieties, variety RAJ 4037 with 180 kg N ha is the best combination for obtaining higher yields and returns on sandy clay loam soils of Southern Telangana region of Andhra Pradesh CHAPTER-

Combined inoculation of rhizobia on the cowpea development in the soil of Cerrado

BBiological nitrogen fixation (BNF) plays an important role in the cowpea cultivation. This study aimed to assess the foliar levels of chlorophyll and the yield components of cowpea subjected to combined inoculation of rhizobia in Cerrado soil. The experiment was carried out in field conditions, from December of 2014 to the march of 2015, in Rondonopolis, Mato Grosso, using randomized block design with ten treatments and three replicates. Were tested the single strains MT8 and MT15 (both of R. tropici), MT16 (R. leguminosarum), BR3267 (Bradyrhizobium japonicum), the strains combinations MT8+MT15, MT8+MT16, MT15+MT16, and MT8+MT15+MT16, nitrogen fertilization (70 kg ha-1 of N-urea), and absolute control (without inoculation of rhizobia and without nitrogen fertilization). Data were subjected to analysis of variance and the averages were compared by orthogonal contrast and F test (p≤0.05). Were assessed the Falker chlorophyll index (at the 40 and 60 days after sowing), number and dry matter of nodules (at the 40 days after sowing), number of pods per plant, grains yield, the concentration and accumulation of nitrogen in grains, and crude protein. The number of pods per plant was increased 33.6% in the combination MT8+MT15. The same effect was observed for the yield grain, which presented an increase of 8.7%, 13.8%, and 16.7% in the combinations MT8+MT16, MT15+MT16, and MT8+MT15, respectively. The nitrogen accumulation in the grains increased 42.7% with the inoculation of MT15 strain. The cowpea responds positively to the usage of combinations of rhizobia strains.

The impact of weather conditions on the yield of winter triticale and content of macroelements in grain

The purpose of this work was to determine the impact of weather conditions during the spring and summer growth of winter triticale on the yield and content of nutrients in its grain. The research results were achieved from a controlled field experiment carried out at the Experimental Station of the University of Warmia and Mazury in Olsztyn, located in Tomaszkowo near Olsztyn (53o42′ N; 20o26′ E). The impact of weather factors during the spring and summer growth of winter triticale on the yield and content of nutrients in its grain was explained by correlation and multiple regression analyses. The duration of the spring and summer growing season (b′ = 0.929**) and the average daily temperatures during the plant growth (b′ = 0.409*) had the strongest, significantly positive impact on winter triticale yield. A significant linear correlation was found only between the content of nitrogen and potassium in winter triticale grain and the selected weather parameters. The nitrogen content depended on the number of plant growing days and average minimum daily temperature, while the potassium content was affected by the number of spring and summer growing days, average daily temperature, total precipitation volume and the number of days with precipitation. Considering the cumulative impact of the examined weather parameters on the content of macroelements in triticale grain, a significant effect was found for phosphorus and potassium, whose levels depended, to the largest extent, on the precipitation volume and number of days without precipitation ≥10 days, respectively. The content of phosphorus and nitrogen in grain was significantly negatively correlated with the yields of winter triticale.

The Nitrate-Inducible NAC Transcription Factor TaNAC2-5A Controls Nitrate Response and Increases Wheat Yield.

Nitrate is a major nitrogen resource for cereal crops; thus, understanding nitrate signaling in cereal crops is valuable for engineering crops with improved nitrogen use efficiency. Although several regulators have been identified in nitrate sensing and signaling in Arabidopsis (Arabidopsis thaliana), the equivalent information in cereals is missing. Here, we isolated a nitrate-inducible and cereal-specific NAM, ATAF, and CUC (NAC) transcription factor, TaNAC2-5A, from wheat (Triticum aestivum). A chromatin immunoprecipitation assay showed that TaNAC2-5A could directly bind to the promoter regions of the genes encoding nitrate transporter and glutamine synthetase. Overexpression of TaNAC2-5A in wheat enhanced root growth and nitrate influx rate and, hence, increased the root's ability to acquire nitrogen. Furthermore, we found that TaNAC2-5A-overexpressing transgenic wheat lines had higher grain yield and higher nitrogen accumulation in aerial parts and allocated more nitrogen in grains in a field experiment. These results suggest that TaNAC2-5A is involved in nitrate signaling and show that it is an exciting gene resource for breeding crops with more efficient use of fertilizer.

Effect of tillage practices and nutrient management on nitrogen content, uptake and yield of sorghum [Sorghum bicolor(L.) Moench

A field experiment was conducted during two consecutive kharif seasons of 2010 and 2011 at the Instructional Farm, Rajasthan College of Agriculture, Udaipur. The soil of the experimental field was clay loam in texture with medium in available nitrogen (268.40 and 270.80 kg/ha) and phosphorus (19.80 and 19.70 kg/ha) and high in available potassium (288.52 and 290.50 kg/ha) and alkaline in reaction with pH 7.85 and 8.01 during 2010 and 2011, respectively. The experiment consisting of 18 treatment combinations and replicated four times was set out in split plot design with three tillage practices (conventional, reduced and minimum tillage) as main plots and six nitrogen management treatments (control, 100% through urea, 50% through chemical fertilizer+50% through VC, 50% through chemical fertilizer+50% through FYM, 25% through chemical fertilizer+75% through VC and 25% through chemical fertilizer+75% through FYM as sub-plot treatments. Sorghum variety CSV-23 was taken as test crop during both the years. Maximum content and uptake of nitrogen in grain and fodder were also observed through 100% chemical source.

Effect of different nitrogen level on nutrients accumulation, transfer and nitrogen utilization efficiency of dry land oil flax

Field experiments were carried out to determine the effect of different nitrogen application rates on nitrogen nutrient uptake,transfer and nitrogen utilization efficiency of dry land oil flax. The results indicated that different nitrogen application rates affected nitrogen nutrient uptake,accumulation and transfer at different growth stages,and changes tendencies were consistant. The amount of nitrogen translocation from leaf,translocation efficiency and contribution to grain were 89. 18%,83. 36% and 86. 36% higher than from stem. The nitrogen in grain,among which 47. 10%-57. 66% was transferred from leaf,22. 46%-30. 94% was transferred from stem and 21. 00%-30. 48% was absorbed from soil. The result indicated that compared to no nitrogen application,the yield of nitrogen treatments( as 27. 6,55. 2 and 82. 8 kg·hm-2) increased 10.21%,16.92% and 15.55%,respectively. The nitrogen transfer amounts,transfer efficiency and contribution efficiency of leaf and stem to grain were maximum when the nitrogen application rate was 55. 2kg·hm-2. With increased nitrogen application rate,apparent nitrogen recovery efficiency of oil flax first increased then decreased. The partial nitrogen factor productivity of oil flax decreased significantly. After taking into account of grain yield,nitrogen utilization efficiency and ecological environment,the recommended nitrogen fertilizer rate for dry land oil flax was 27. 6-55. 2kg·hm-2at the soil fertility level in our experiment.

Effects of straw mulch on growth and yield of durum wheat during transition to Conservation Agriculture in Mediterranean environment

In Mediterranean environment, the transition to Conservation Agriculture (CA) poses as major issue the scarce accumulation of residues on soil surface; covering the soil with additional straw mulch could be a proven strategy for soil and water conservation, especially where durum wheat is the main crop, until reaching a layer of adequate thickness, typical of the stabilized CA systems.Two field trials were carried out from 2010 to 2012 in a representative area of Southern Italy during the first two years of transition to CA. Durum wheat was grown under three increasing levels of straw added as soil mulching: 5.0tha−1 (100% mulch cover (100%MC)), 2.5tha−1 (50%MC) and 1.5tha−1 (30%MC), plus a CONTROL. The influence of such additional straw on soil water and nutrient availability, physiological traits, growth and yield of durum wheat was assessed, as well as the necessary amount of additional straw was estimated.Both years of study indicated that root-zone moisture contents, monitored at 5cm depth starting from the beginning of head emergence, were significantly improved by mulching, with the highest differences detected between 100%MC and CONTROL (36 and 41% higher in 2011 and 2012, respectively). 100%MC exhibited also the significant lowest concentration of nitrate-N (9mgL−1 on average), K, Ca and Mg in soil solution. Additional straw at higher rates improved crop physiology: leaf water content (LWC) was highest in 100%MC (48.3%) and lowest in CONTROL (38.2%); SPAD and NDVI values (chlorophyll content) were respectively increased by 25% and 22% in 100%MC and by 15% and 17% in 50%MC, with respect to CONTROL. Nitrogen Nutrition Index (NNI) at anthesis was highest in 100%MC (0.97 vs. 0.50 in CONTROL). Significant high correlations were found between yield components and water as well as NO3− availability in soil solution (number of grainsm−2 vs. NO3− in soil solution R2 0.89; number of grainsm−2 vs. soil water R2 0.96). Yield was significantly affected by crop dry weight and N status at anthesis (0.49kgm−2 in 100%MC vs. 0.27kgm−2 in CONTROL, averaged over years). Moreover, the plots with higher amount of additional straw (100%MC and 50%MC) promoted significantly the accumulation of nitrogen in grains (0.56mgNgrain−1 in 2011 and 0.51mgNgrain−1 in 2012 in 50%MC).Under our experimental conditions, 1.5tha−1 of straw added as mulching are enough to significantly produce higher yields, although to exert significant positive effects both on soil and on crop physiological indicators, 2.5tha−1 of wheat straw are necessary. However, increasing the amount of crop residues until 5tha−1, crop performances and soil characteristics continue to significantly improve.

Dynamics of the nitrogen uptake by spring barley at injection application of nitrogen fertilizers

Influence of CULTAN system (controlled uptake long term ammonium nutrition) on the nitrogen uptake by spring barley (Hordeum vulgare L.) was observed at 5-year small-plot field experiments under conditions of the Czech Republic (central Europe). Nitrogen uptake by CULTAN-fertilized plants was more even during vegetation period probably due to delayed term of fertilizer application. Nitrogen concentration in the aboveground biomass at BBCH 51 and in straw had no effect on grain yield. Post-heading nitrogen uptake as well as contribution of nitrogen translocation to total nitrogen in grain did not differ among both nitrogen fertilization treatments. Increase in grain size of spring barley by the CULTAN system can be explained by tendency to lower number of ears per area rather than by prolonged nitrogen uptake from soil. Lower protein content in grain of CULTAN-fertilized spring barley can be caused by increase in grain retained on a 2.5 mm sieve and also decrease in total nitrogen concentration in above-ground biomass at BBCH 51. No significant effect of CULTAN treatment on nitrogen use efficiency and nitrogen uptake efficiency was recorded. Significantly higher nitrogen utilization efficiency at CULTAN treatment could be explained by lower grain protein content compared to conventional treatment.

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].

Effect of storage time and Furolan on the contents of nitrogen, protein and non protein nitrogen in winter wheat grain

This study was carried out to investigate the effect of storage time and growth regulator, Furolan on protein, non-protein nitrogen and nitrogen contents of three varieties of winter wheat grains namely Batko, Diya and Krasnodar 99. The contents of the nitrogen, protein and non-protein nitrogen in winter wheat grain were determined by different protocols during the full ripeness phase of the grain and the period of 12 months storage. The grains (both the control and experimental) were kept in storage for varied periods under normal conditions. Krasnodar 99 variety responded most to the Furolan and recorded an increase in protein nitrogen content by 46.3% followed by 24.9% in experimental Batko variety and 17.4% in Diya’s variety in comparison with the control. The content of protein nitrogen in the grain of experimental Batko variety increased up to the seventh month of storage, and then decreased by the 12th month of storage. In the control—a similar tendency of change in this parameter was observed. It was noted that seven months of storage is critical in change dynamics of the content of non-protein nitrogen in the selected winter wheat varieties studied.