Search Results (58)

Optimizing the efficiency of fertilizer use is critical for sustainable maize production and food security, particularly in smallholder systems. Sub-optimal application rates pose a significant risk of soil nutrient depletion and low productivity. Split plot experiments were conducted across four locations in Ghana’s Guinea Savannah using seven maize varieties from three different maturity classes. The study assessed the response to nitrogen fertilizer applications (0, 60, 90, and 120 kg N ha⁻¹) regarding yield, Agronomic Efficiency (AE_N), Water Use Efficiency (WUE), and economic feasibility. Grain yields across locations and varieties demonstrated a strong linear response to nitrogen fertilization. The 90 kg N ha⁻¹ application generally produced the highest AE_N for all sites and varieties. Gross Revenue (GR) and WUE increased with higher N rates, with Value-to-Cost Ratios (VCR) consistently exceeding 2. Applying 90 kg N ha⁻¹ resulted in statistically similar Gross Revenues (GRs) to the 120 kg N ha⁻¹ fertilization. Different maturity classes significantly impacted fertilizer efficiency in semi-arid Ghana, with intermediate varieties outperforming extra-early ones. Though a 90 kg N ha⁻¹ rate was generally identified as the economically optimal rate of N fertilization for the locations, targeted fertilizer recommendations based on maize maturity groups and location are strongly advised. Full article

The application of urease inhibitors (UIs) and optimizing nitrogen (N) split application ratio (NSR) can both minimize ammonia (NH₃) volatilization and increase rice yield. However, few studies have analyzed the combined effects of these two practices with straw returning on rice yield and NH₃ volatilization. In this study, based on a field experiment involving rice yield, aboveground dry matter (ADM), crop N uptake (N_upt), and NH₃ volatilization from 2018 to 2019 in Sichuan Basin, China, the WHCNS (soil water heat carbon nitrogen simulator) model was used to simulate the effects of straw returning, UI, and NSR on rice growth and NH₃ volatilization. The results showed that the WHCNS model performed well in simulating rice growth and NH₃ volatilization. With straw return amount exceeding 4 t ha⁻¹, rice yield increased slowly or stabilized, while N_upt and NH₃ volatilization continued to increase. Increasing the panicle fertilizer (PF) proportion enhanced N_upt during the PF stage, thereby promoting yield improvement. The NSR₃ (a 1:1:3 ratio of base fertilizer, tiller fertilizer, and PF) achieved the highest yield, exceeding that of 2:1:2 by 0.29, 0.23, and 0.08 t ha⁻¹ at straw return amounts of 2, 3, and 4 t ha⁻¹, respectively. However, the effects of UI on N_upt and yield enhancement were limited. Furthermore, optimized NSR and the application of UI reduced NH₃ volatilization during the basal or tiller fertilizer stages, leading to an average decrease of 5.5% and 8.5% in total NH₃ volatilization, respectively. Meanwhile, the increase in straw return amount reduced the NH₃ volatilization reduction effects of both practices. Overall, the combination of NSR₃ and UI with the straw return amount of 3 t ha⁻¹ was the optimal practice for balancing food security and environmental benefits in purple soil area. Full article

The balanced application of organic and chemical fertilizers is essential for maintaining soil fertility and crop productivity. To optimize nitrogen (N) balance and maize yield through integrated pig slurry and straw mulching management, a split-plot field experiment was conducted in Northeast China. The study included two straw treatments (straw mulching, S; no straw, NS) and three substitution levels of pig slurry for chemical fertilizer (0%, 20%, and 40%; denoted as M0, M20, and M40). Parameters evaluated included N balance, maize biomass, soil available N, and the mineral N to TN ratio (mineral-N/TN), measured across 0–100 cm at key maize growth stages. Results showed that pig slurry substitution significantly increased soil DON, mineral N, and mineral-N/TN in the topsoil (0–20 cm) at the maize seeding stage and decreased mineral-N/TN at the maize milk (10–40 cm) and maturity (80–100 cm) stages. Meanwhile, straw mulching reduced NH₄⁺-N accumulation in the 0–10 cm of topsoil at the seeding stage, decreased NO₃⁻-N in the 0–40 cm soil layer from the jointing to maturity stages, and lowered the mineral-N/TN ratio in the topsoil, thereby mitigating the risk of N leaching. Notably, the combination of pig slurry substitution and straw mulching slightly increased DON and NO₃⁻-N in the topsoil while significantly reducing the mineral-N/TN in the deep soil layer at the seeding and milk stages. Pig slurry substitution significantly improved maize yield, N uptake, and N use efficiency (NUE). The highest maize yield (14,628 kg ha⁻¹) was observed in the S-M20 treatment, representing a 19% increase compared to NS-M0. N balance analysis indicated that pig slurry substitution alone increased maize yield and N uptake but depleted soil N, whereas straw mulching maintained N surplus. The findings highlight that combining pig slurry with straw mulching optimizes soil N availability and improves sustainable N management and crop productivity in agroecosystems. Full article

This study developed a nitrogen management framework that simultaneously addresses photosynthetic limitations and water scarcity challenges, providing a scalable solution for sustainable wheat production in arid farming systems. Focusing on Xinjiang’s arid region, we investigated how different ratios of basal to topdressed nitrogen fertilization affect photosynthetic mechanisms in drip-irrigated spring wheat. We implemented a split-plot design during the 2020–2021 growing seasons, using two wheat cultivars as main plots: strong-gluten Xinchun 37 (XC37) and medium-gluten Xinchun 6 (XC6). The subplots consisted of five N application treatments: N00: (no nitrogen application, control), N28 (base fertilizer 20%, top dressing 80%, and so on), N37 (3:7), N46 (4:6), and N55 (5:5). The vast majority of indicators performed best under N37 treatment. And LAI, RuBPC (ribulose-1,5-diphosphate ribulose carboxylase) activity, net photosynthetic rate (P_n), yield, and its composition were higher than the rest of the treatments by 0.21~31.75%, 6.94~25.21%, 7.42~40.78%, 0.86~25.44%, and 0.44~12.02%. And intercellular CO₂, concentration (C_i) was lower than other treatments by 7.63~50.60%. Yield showed q highly significant positive correlation with P_n, G_s, T_r, Φ_PSⅡ, and chlorophyll fluorescence parameters, but a negative correlation with C_i. Stepwise regression analysis showed that LAI, P_n, C_i, and RuBPC activity had a significant impact on yield and its compositions. In addition, all index performances of XC37 were better than XC6. Under drip irrigation in arid zones, allocating 30% basal + 70% topdressed N optimally enhances photosynthetic capacity and yield formation in spring wheat, offering a practical pathway for sustainable intensification in water-limited agroecosystems. Full article

Maintaining the long-term viability of a wheat–maize planting system, particularly the synchronous improvement of crop production and soil organic carbon (SOC) sequestration, is crucial for ensuring food security in the North China Plain. A field experiment in which wheat–maize was regarded as an integral fertilization unit was carried out in Shanxi Province, China, adopting a split-plot design with different distribution ratios of phosphorus (P) and potassium (K) fertilizer between wheat and maize seasons in the main plot (A) (a ratio of 3:0, A1; a ratio of 2:1, A2) and different application rates of pure nitrogen (N) during the entire wheat and maize growth period (B) (450 kg·ha⁻¹, B1; 600 kg·ha⁻¹, B2). Moreover, no fertilization was used in the entire wheat and maize growth period for the control (CK). The findings showed that A2B1 treatment led to the highest response, with an average wheat yield of 7.75 t·ha⁻¹ and an average maize yield of 8.40 t·ha⁻¹ over the last 9 years. The highest SOC content (15.13 g·kg⁻¹), storage (34.20 t·ha⁻¹), and sequestration (7.11 t·ha⁻¹) were also observed under the A2B1 treatment. Both enhanced crop yield and SOC sequestration resulted from improvements in cumulative carbon (C) input, soil nutrients, and stoichiometry under the A2B1 treatment. It was confirmed that total N (TN), alkali-hydrolysable N (AN), available P (AP), available K (AK), and the ratios of C:K, N:K, and N:P had positive effects on crop yield through the labile components of SOC and on SOC sequestration through microbial necromass C. To conclude, our findings highlight the urgent need to optimize fertilizer management strategies to improve crop production and SOC sequestration in the North China Plain. Full article

Controlled-release nitrogen fertilizers are gaining popularity in rice (Oryza stavia L.) cultivation for their ability to increase yields while reducing environmental impact. Grain filling is essential for both the yield and quality of rice. However, the impact of controlled-release nitrogen fertilizer on grain-filling characteristics, as well as the relationship between these characteristics and rice quality, remains unclear. This study aimed to identify key grain-filling characteristics influencing rice milling quality, appearance, cooking and eating qualities, and physicochemical properties of starch. In this study, a two-year field experiment was conducted that included four nitrogen management practices: zero nitrogen input (CK), a local high-yield practice with split urea applications (100% urea, CU), a single basal application of 100% controlled-release nitrogen fertilizer (CRNF), and a basal application blend of 70% controlled-release nitrogen fertilizer with 30% urea (CRNF-CU). The results showed that a sufficient amount of carbohydrates for the rice grain-filling process, as indicated by a higher sugar–spikelet ratio, is essential for improving grain quality. An increased sugar–spikelet ratio enhances the grain-filling process, resulting in an elevated average grain-filling rate (G_mean) and the peak grain-filling rate (G_max), while also reducing the overall time required for grain filling (D). Compared to CU, CRNF and CRNF-CU treatments did not significantly change milling qualities, but reduced the chalky kernel rate and chalkiness, thereby enhancing the appearance quality. These treatments increased the amylose and amylopectin contents while reducing protein content, though the proportion of protein constituents remained unchanged. These treatments led to larger starch granules with notably smoother surfaces. Additionally, CRNF and CRNF-CU reduced relative crystallinity and structural order, while increasing the amorphous structure in the outer region of starch granules, which lowered rice starch crystal stability. The treatments also increased viscosity and improved the thermodynamic properties of starch, resulting in enhanced eating and cooking quality of the rice. In conclusion, the CRNF-CU is the most effective strategy in this study to enhance both grain yield and quality. This practice ensures an adequate carbohydrate supply for grain filling, which is essential for efficient grain filling and improved overall quality. Full article

Crude protein (CP) reduction and amino acid (AAs) supplementation is an interesting cost-reducing strategy for environmental compliance. The objective of this work is to study productive performances of heavy Duroc X (Landrace X Large white) male and female pigs during the finishing stage under a 2% CP reduction with crystalline AA supplementation. A total of 60 entire male and 60 female pigs (means ± standard deviations: 109 ± 4.9 days of age; 67.9 ± 7.18 kg of body weight) were distributed in split-sex pens (6 pigs/pen) and fed ad libitum. Two isoenergetic diets were provided (145 and 125 g CP/kg with AA supplementation, control and low-CP) during the final 42 days of finishing period. Growth performance, carcass and meat traits were evaluated. The fixed effects of dietary treatment, sex and their interaction were considered and simple least squares models used. Males were 7.25% heavier (p < 0.001) and had 16% higher average daily gains (p < 0.0001) than females in both treatments with no differences in feed intake or feed conversion ratio (p > 0.05). Nitrogen efficiency was 35% higher in low-CP males. Little difference was found for most carcass and meat traits between treatments. Males had 7–8% higher loin subcutaneous fat thickness in both dietary treatments (p = 0.011). Males and females of the low-CP diet showed higher fat and saturated fat contents than controls (p = 0.020). A 20 g/kg CP reduction with AA supplementation is an efficient strategy during the finishing phase without productivity losses in heavy Duroc sire line genotypes of both sexes. Full article

To address the prevailing problems of high water and fertilizer input and low productivity in Isatis tinctoria L. production in the Hexi Corridor in China, the effects of different irrigation amounts and nitrogen application rates on growth characteristics, photosynthetic physiology, root yield, and quality of I. tinctoria plants were studied with the aim of obtaining the optimal irrigation level and nitrogen application rate. From 2021 to 2023, we established a two-factor split-plot experiment in the oasis irrigation area with three irrigation amounts (sufficient water, medium water, and low water are 100%, 85%, and 70% of the typical local irrigation quota) for the main zone; three nitrogen application rates (low nitrogen, 150 kg ha⁻¹, medium nitrogen, 200 kg ha⁻¹, and high nitrogen, 250 kg ha⁻¹) for the secondary zone; and three irrigation amounts without nitrogen as the control to explore the response of these different water and nitrogen management patterns for I. tinctoria in terms of growth characteristics, photosynthetic physiology, root yield, and quality. The results showed the following: (1) When the irrigation amount was increased from 75% to 100% of the local typical irrigation quota and the nitrogen application rate was increased from 150 to 250 kg ha⁻¹, while the plant’s height, leaf area index, dry matter accumulation in the stem, leaf, and root, as well as the net photosynthetic rate (Pn), the stomatal conductance (Gs), and the transpiration rate (Tr) of I. tinctoria increased gradually, and the root–shoot ratio decreased. (2) When the irrigation amount increased from 75% to 100% of the local typical irrigation quota, the yield and net proceeds of I. tinctoria increased from 43.12% to 53.43% and 55.07% to 71.61%, respectively. However, when the irrigation quota was 100% of the local typical irrigation quota, and the nitrogen application rate increased from 150 to 200 kg ha⁻¹, the yield of I. tinctoria increased from 21.58% to 23.69%, whereas the increase in nitrogen application rate from 200 to 250 kg ha⁻¹ resulted in a decrease in the yield of I. tinctoria from 10.66% to 18.92%. During the 3-year experiment, the maximum yield of I. tinctoria appeared when treated with sufficient water and medium nitrogen, reaching 9054.68, 8066.79, and 8806.15 kg ha⁻¹, respectively. (3) The effect of different water and nitrogen combination treatments on the root quality of I. tinctoria was significant. Under the same irrigation level, increasing the nitrogen application rate from 150 to 250 kg ha⁻¹ could increase the contents of indigo, indirubin, (R,S)–goitrin, total nucleoside, uridine, and adenosine in the root of I. tinctoria from 3.94% to 9.59%, 1.74% to 12.58%, 5.45% to 18.35%, 5.61% to 11.59%, 7.34% to 11.32%, and 14.98% to 54.40%, respectively, while the root quality of I. tinctoria showed a trend of first increasing and then decreasing under the same nitrogen application level. (4) AHP, the entropy weight method, and the TOPSIS method were used for a comprehensive evaluation of multiple indexes of water–nitrogen coupling planting patterns for I. tinctoria, which resulted in the optimal evaluation of the W3N2 combination. Therefore, the irrigation level was 100% of the local typical irrigation quota, the nitrogen application rate should be appropriately reduced, and controlling the nitrogen application rate at the level of 190.30–218.27 kg ha⁻¹ can improve water–nitrogen productivity yields for I. tinctoria and root quality. The results of this study can provide a theoretical basis and technical support for a more reasonable water and fertilizer management model for the I. tinctoria production industry in the Hexi Corridor in China. Full article

Incorporating crop residues into the soil is an effective method for improving soil carbon sequestration, fertility, and crop productivity. Such potential benefits, however, may be offset if residue addition leads to a substantial increase in soil greenhouse gas (GHG) emissions. This study aimed to quantify the effect of different crop residues with varying C/N ratios and different nitrogen (N) fertilizers on GHG emissions, yield, and yield-scaled emissions (GHGI) in winter wheat. The field experiment was conducted during the 2018–2019 winter wheat season, comprising of four residue treatments (no residue, maize residue, soybean residue, and maize-soybean mixed residue) and four fertilizer treatments (control, urea, manure, and manure + urea). The experiment followed a randomized split-plot design, with N treatments as the main plot factor and crop residue treatments as the sub-plot factor. Except for the control, all N treatments received 150 kg N ha⁻¹ season⁻¹. The results showed that soils from all treatments acted as a net source of N₂O and CO₂ fluxes but as a net sink of CH₄ fluxes. Soybean residue significantly increased soil N₂O emissions, while mixed residue had the lowest N₂O emissions among the three residues. However, all residue amendments significantly increased soil CO₂ emissions. Furthermore, soybean and mixed residues significantly increased grain yield by 24% and 21%, respectively, compared to no residue amendment. Both soybean and mixed residues reduced GHGI by 25% compared to maize residue. Additionally, the urea and manure + urea treatments exhibited higher N₂O emissions among the N treatments, but they contributed to significantly higher grain yields and resulted in lower GHGI. Moreover, crop residue incorporation significantly altered soil N dynamics. In soybean residue-amended soil, both NH₄⁺ and NO₃⁻ concentrations were significantly higher (p < 0.05). Conversely, soil NO₃⁻ content was notably lower in the maize-soybean mixed residue amendment. Overall, our findings contribute to a comprehensive understanding of how different residue additions from different cropping systems influence soil N dynamics and GHG emissions, offering valuable insights into effective agroecosystems management for long-term food security and soil sustainability while mitigating GHG emissions. Full article

Research has been increasingly focusing on the preservation of the biodiversity of vegetable crops under sustainable farming management. An experiment was carried out in southern Italy on Brassica oleracea L. var. botrytis, landrace Gigante di Napoli, to assess the effects of two transplanting times (9 September and 7 October), in factorial combination with five nitrogen–potassium ratios (0.6; 0.8; 1.0; 1.2; and 1.4) on plant growth, yield, and quality of cauliflower heads. A split-plot design was used for the treatment distribution in the field, with three replications. The earlier transplant and the 1.2 N:K ratio led to the highest yield, mean weight, and firmness of cauliflower heads which were not significantly affected by both transplanting time and N:K ratio in terms of colour components. The 1.2 N:K ratio led to the highest head diameter with the earlier transplant, whereas the 1.0 ratio was the most effective on this parameter in the later crop cycle. The highest nitrate, nitrogen, and potassium concentrations in the heads were recorded with the earlier transplanting time. Antioxidant activity, ascorbic acid, and polyphenol content increased with the rise of the N:K ratio. The element use efficiency was constantly negative with the N:K increase for nitrogen and was augmented until the 1.2 ratio for potassium. The results of our investigation showed that the optimal combination between transplanting time and N:K ratio is a key aspect to improve head yield and quality of the cauliflower landrace Gigante di Napoli, under the perspective of biodiversity safeguarding and valorisation. Full article

Understanding the stoichiometry of extracellular enzymes in soil, particularly in relation to nutrient acquisition (e.g., carbon, nitrogen, phosphorus), provides valuable insights into microorganisms’ resource requirements. This study investigates the metabolic constraints of soil microorganisms in response to different growth stages of apple trees under various soil management practices. A 14-year long-term experiment with a split-plot design was conducted, where the main plots received different cover crop treatments (bare vs. cover crop), and subplots were subjected to four fertilizer treatments (CK, M, NPK, MNPK). The significant main and interactive effects of cover crops, fertilizer treatment, and growth period on soil nutrients were observed (p < 0.001). Both cover crop and fertilizer treatments significantly increased the soil organic matter content, with implications for orchard resilience to drought. However, the cover factor alone did not notably influence soil carbon–nitrogen ratios or microbial communities. Microbial carbon limitations were driven by soil water dynamics and microbial biomass, while microbial phosphorus limitations were closely linked to total nitrogen levels. The results underscore the combination of cover crops and MNPK fertilizer-enhanced soil nutrient levels and enzyme activities, mitigating microbial carbon and phosphorus limitations. These findings suggest practical strategies for optimizing fertilization practices to improve soil fertility and address nutrient constraints in orchard ecosystems. Full article

This study addresses the uncertainty regarding the potential of a one-time basal application of mixed nitrogen (N) fertilizer to optimize both yield and eating quality of late-maturing medium japonica rice Nangeng 9108 and Fenggeng 1606 in the Yangtze River Delta. Six distinct combinations of blended N fertilizers were evaluated, with conventional split fertilization serving as the control. The blended formulations combined controlled-release N fertilizer (CRNF) and quick-acting N fertilizer (CNF) at a 1:1 ratio. Furthermore, the CRNF component was a combination of two CRNF types with varied N-release durations at a 4:1 ratio, leading to treatments labeled A1, A2, B1, B2, C1, and C2. Over a 2-year study, treatments B1, B2, C1, and C2 matched or surpassed the control in grain yield, with C1 and C2 yielding 2.83–4.85% more. Among the above high-yield treatments, C1 showcased the best rice eating quality, which exhibited increased peak viscosity, hot viscosity, cool viscosity, breakdown, and taste value of milled rice, and a decrease in rice protein content (PC). This enhancement in quality correlated with N accumulation patterns and their interplay with sink capacity. Specifically, a higher N accumulation resulted in a robust sink capacity under the C1 treatment, thus reducing N availability per unit sink capacity (NAV) and rice PC, ultimately enhancing the overall palatability of milled rice. Conclusively, the C1 fertilizer blend demonstrates potential in concurrently boosting yield and eating quality of late-maturing medium japonica rice in the region. Full article

The chromatographic conditions were optimized using headspace gas chromatography, and a simple and rapid method was established for the simultaneous determination of five residual solvents in ursodeoxycholic acid raw materials. The corresponding quality standards were revised. The research results demonstrate that by utilizing a capillary column with a stationary phase consisting of 5% phenyl-95% dimethylpolysiloxane (HP-5, 30 m × 0.32 mm, film thickness 1.0 µm) and a flame ionization detector in conjunction with a headspace injection system and a programmed temperature ramping method, satisfactory analytical results can be achieved. The specific operating conditions are as follows: an initial column temperature of 45 °C, followed by a column temperature increase at a rate of 5 °C per minute up to 60 °C, then a further increase at a rate of 10 °C per minute up to 100 °C, and finally a rapid increase at a rate of 40 °C per minute up to 200 °C, where it is held for 10 min. Nitrogen is employed as the carrier gas at a flow rate of 1 mL/min with a split ratio of 14:1. The headspace vial temperature is maintained at 100 °C, with a sample equilibration time of 45 min. The concentration of methanol ranged from 0.06 mg/mL to 0.3 mg/mL, and the concentrations of acetone, tert-butanol, ethyl acetate, and triethylamine showed a good linear relationship with the peak area within the range of 0.1 mg/mL to 0.5 mg/mL (r = 0.999); The quantitation limits for methanol, acetone, tert-butanol, ethyl acetate, and triethylamine were 4.2, 0.9, 1.5, 1, and 0.1 μg/mL, respectively, with detection limits of 1.2, 0.25, 0.025, 0.3, and 0.025 μg/mL, respectively. The recovery rates of each solvent ranged from 92.9% to 106.0%, with RSD% (n = 9) less than 3.8%; the method exhibited good repeatability, with RSD% (n = 6) less than 2.5%. Furthermore, the robustness is good. The established method is simple, accurate, specific, and highly sensitive, and can be used for the simultaneous and rapid determination of five residual solvents in ursodeoxycholic acid raw materials. Full article

A field experiment was conducted at Sardar Vallabhbhai Patel University of Agriculture and Technology, Meerut (U.P.), India, during the kharif season (June–September) in 2019 to study the impact of planting techniques and nutrient management on the crop productivity and profitability of rice (Oryza sativa L.). The treatment comprised four planting techniques as the main (M) treatments and six fertility levels as subplot (S) treatments in a split-plot design with three replications. The results of the experimentation revealed that Conventional Tillage Transplanted rice and the combination of nitrogen chemical fertilizer with organic nitrogen from FYM (farmyard yard manure) resulted in the highest effective tillers, grains per panicle and grain yield. Conventional Tillage Transplanted rice (M2) stood out with the highest gross returns (USD 1151.27 per ha) and net returns (USD 690.03 per ha) due to its superior yield. The Reduce Tillage Transplanted rice (M1) and Unpuddled Transplanted rice (M4) techniques produced good yields, with net returns of USD 564.97 per ha and USD 634.93 per ha, respectively. Among the fertility levels, 75% NPK + 25% N FYM (S5) led with the highest gross returns (USD 1257.74 per ha) and net returns (USD 815.90 per ha). The treatment with 100% NPK + 25% N from FYM (S6) also performed well, with net returns of USD 837.70 per ha, emphasizing the value of combining chemical fertilizers and organic sources for optimal results. Among the planting techniques, M2 resulted in the highest benefit-cost ratio (1.5), while S5 yielded the highest benefit-cost ratio (1.85), indicating their economic viability Full article

Imbalanced use (form, quantity, and ratio) of nitrogen fertilization can result in decreased grain yields and increased nitrogen loss, leading to adverse effects on overall environmental quality. Globally, limited empirical research has been conducted on the comprehensive effects of different levels of N that can significantly influence wheat agronomic and genotypic traits. Therefore, this study aimed to evaluate wheat genotypes for two consecutive years (2020–2021 and 2021–2022) under different N fertilization treatments: N0 (native N, without external application of N), N75 (½ of the recommended dose of N), and N150 (recommended dose of N). The study findings revealed that ‘HD 3249’ and ‘HD 3117’ were the top-performing genotypes in terms of grain yield (5.3 t ha⁻¹; 5.0 t ha⁻¹), straw yield (6.9 t ha⁻¹; 6.7 t ha⁻¹), biological yield (12.2 t ha⁻¹; 11.8 t ha⁻¹), and harvest index (42.9%; 42.4%). In particular, the application of N75 and N150 increased grain yields by 142.6% and 61.3%, respectively; straw yields by 72.3%; and by 110.6% over N0. Furthermore, N levels (N75 and 150) significantly increased the higher concentration of N in grain (23.1% and 33%) and straw (21.1% and 29.8%); N uptake in grain (70.2 and 104.2) and straw (64.8 and 41.5); and total N uptake (68.8% and 101.4%) than N0, respectively. Additionally, correlation analysis revealed that there were positive correlations between yields, harvest index as well as N concentration and uptake. This study identified the two elite genotypes, ‘HD 3249’ and ‘HD 3117’, with N150 splits giving a better response, which can be used as selection criteria for developing wheat varieties that are more efficient in using nitrogen, leading to high yields and N uptake. Full article