Timing Of Nitrogen Fertilization Research Articles

Nitrogen status of durum wheat derived from Sentinel-2 satellite data in Central Italy

In agriculture, nitrogen (N) is a key element in plant nutrition that affects, both positively and negatively, the productive and qualitative results of the crop. Accurate quantification of nitrogen levels is crucial for devising effective plant nutrition strategies. The objective of this study was to validate a novel method to estimate the N content at different phenological stages of durum wheat (Triticum durum Desf. cv. Iride) under different N management strategies (chemical synthetic fertilizer - SYN and organic fertilizer - ORG) in Italy, using the Nitrogen Nutrition Index (NNI)as a diagnostic tool for improving nitrogen fertilization timing and doses. The NNI is the ratio between the actual crop nitrogen content (Na) and the optimal level (Nc) required for ideal growth conditions.On ground level, Leaf Area Index (LAI) , Canopy reflectance, leaf chlorophyll content (LCC) and N concentration in leaves were measured. At landscape level, LAI and Canopy Chlorophyll Indices (CIs) were derived from Sentinel 2 (S2) multispectral images captured on the same days as the ground measurements: Chlorophyll Indexes were used for estimating the canopy chlorophyll content, CCC. Na in leaves and canopy were calculated from LCC and CCC respectively.In the study area, Nc is Nc=4.65LAI–0.35, R2=0.92. Among the tested Chlorophyll Indices (CIs) regression models, the linear regression was the more accurate to predict Na content, even though most of the tested Chlorophyll Indices (CIs) showed an R2 > 0.8,a. The best-performing spectral index in both calibration and validation steps resulted from the IRECI, with R2=0.90 and RMSE=0.31. The developed NNI well-captured the seasonal N dynamic for durum wheat, under different N management and meteorological conditions. The NNI calculated from S2 data for crop N status assessment, showed to be an accurate estimation of the Nitrogen Nutrition Index and can be used for the fertilization plans without costly on ground measurements.

Nitrogen fertilization timing and rate influence N recovery efficiency and rice yield

AbstractNitrogen (N) fertilizer management in rice (Oryza sativa L.) varies with production practices. In drill‐seeded, delayed‐flood production systems, the most common production practice in Louisiana N fertilizer is applied at two application timings. The first application timing is just before the permanent flood is established. The second application is at midseason. Nitrogen fertilization before flooding is critical for maximum N uptake, nitrogen recovery efficiency (NRE), and yield. Field experiments were conducted from 2017 to 2020 to evaluate N timing effects on N uptake, NRE, and rice yield. The rice cultivar CL153 was drill‐seeded into a stale seedbed at a seed rate of 85 kg ha−1. Fertilizer‐N was applied utilizing multiple application timings and rates adding up to a seasonal rate of 155 kg ha−1 across treatments. A single N application 1‐day before flooding significantly increased grain yield in all trials, ranging from 8523 kg ha−1 in 2019 to 11,322 kg ha−1 in 2018. Compared to post‐flood applications, preflood N increased plant height, N uptake, and NRE. Split N application rates and timings after flooding did not impact rice yield or its agronomics, such as height, aboveground biomass, and time of heading. NRE and yield were significantly correlated (r = 0.805; p < 0.001). Our results indicated that a single N application before flooding has the potential to be an alternative option for N management in the drill‐seeded, delayed‐flood rice system.

Mowing and nitrogen management guidelines for superior rice ratoon yields

Forage-grain ratoon rice (FG-RR) is a dual-cropping system, with forage harvested in the initial season and grain during the regeneration phase. While it is known that the timing of mowing and nitrogen (N) fertilization are key drivers that influence FG-RR production, physiological mechanisms ensuing mowing and N fertilizer application remain unclear. We conducted field experiments in 2021 and 2022 to investigate the yield and growth characteristics of ratooned crops (RC) under various mowing treatments (heading, milk-ripening, dry-ripening and maturity) using three N levels (135, 270, and 405 kg ha−1), two rice genotypes, Taoyouxiangzhan (TYXZ) and Liangyou 6326 (LY6326). Our results demonstrate a significant increase in ratoon yield when mowing occurred at heading or milk-ripening stages compared with maturity, with a yield increase of 2.2-fold when mowing occurred at heading. Early mowing stages increased stubble biomass (up to 73 %) and non-structural carbohydrate (up to 198 %) compared with that at maturity. Mowing at heading or milk-ripening improved accumulated temperature and light exposure, and when coupled with higher N application (270 kg ha−1 N), amplified ratoon ability to recover. Collectively, these factors raised leaf area index, canopy light interception and biomass. Hierarchical partitioning analysis underscored the substantial yet indirect influence of environmental drivers of ratoon yield, alongside a direct driver of growth, particularly thermal sum. We conclude that mowing at heading and milk-ripening with 270 kg ha−1 N elicits optimal ratoon yield with forage production, although further studies are required to determine how these guidelines vary across environments.

Grazing intensity and nitrogen fertilization timing to increase soil organic carbon stock and nitrogen in integrated crop-livestock systems

ABSTRACT Integrated crop-livestock systems (ICLS) foster synergistic relationships to increase nitrogen (N) cycling and soil organic carbon (SOC) accrual in agricultural setups. This study evaluated how the grazing intensity and N fertilization (rates and timing) affect both SOC and N fractions, and soil organic matter chemical composition in an ICLS managed under no-tillage in an Oxisol, six years after initiation. The ICLS was compared to a nearby pasture (PA) and a native forest (NF). The treatments consisted of two grazing intensities: Low Sward Height (LH) and High Sward Height (HH) were maintained with high and low stocking rates, respectively. The HH varied between 0.20 and 0.60 m, and LH between 0.10 and 0.30 m according to the plant forage species throughout the experiment. Fertilization using 200 kg ha -1 N-urea, not splitting up, was conducted at two timings, either at the winter pasture establishment (autumn), about 35 days after sowing or during the summer cash crop cycle (spring). Total N amount per year, including both phases, pasture and cash crop was the same for all treatments. The SOC and N contents were assessed in soil and particulate organic matter (POM), while carbon (C) and N stocks were specifically determined in the soil. Soil organic matter composition was characterized by FTIR. The combination of HH and N fertilization during the pasture phase increased the content of C from 36.1 to 39.9 ± 0.7 g C kg -1 and of N from 2.7 to 3.2 ± 0.1 g N kg -1 . The SOC stocks varied from 37.3 to 41.1 ± 0.7 Mg C ha -1 , and the N stocks from 2.1 to 3.3 ± 0.1 Mg N ha -1 at 0.0-0.10 m soil layer. The SOC content of the POM and the soil organic matter chemical composition determined by FTIR were mainly affected by the grazing intensity. The HH led to an increased in C content within the POM fraction, reaching values of 51.6 ± 1 and 49.2 g C kg -1 , respectively to N crop fertilization and N pasture fertilization. Land-use changed how organic functional groups were stored in soil organic matter fractions. The NF had a greater abundance of aliphatic and phenol in the MAOM, while pasture and ICLS systems had greater aliphatic in the POM fraction. In ICLS, SOC accrual was positively associated with more recalcitrant organic functional groups of phenol, aromatic, and carbonyl C-O. The HH increases SOC accrual, while N-fertilization on pasture ensures adequate nutrition of plants and animals during the winter ICLS phase, at the same time as providing greater residual N for subsequent cash crops through enhanced catalyzed by ruminants. Therefore, grazing and fertilization management strategies should be considered to promote sustainable agriculture intensification with ICLS.

Effect of different NPK fertilization timing sequences management on soil-petiole system nutrient uptake and fertilizer utilization efficiency of drip irrigation cotton

In order to elucidate the effects of different nitrogen (N), phosphorus (P), and potassium (K) fertilization timing sequences management on nutrient absorption and utilization in drip irrigation cotton, field experiments were conducted from 2020 to 2021. There are six timing sequences management methods for NPK fertilization (S1–S6: 1/3Time N–1/3Time PK–1/3Time W, 1/3Time PK–1/3Time N–1/3Time W, 1/2Time NPK–1/2Time W, 1/4Time W–1/4Time N–1/4Time PK–1/4Time W, 1/3Time W–1/3Time NPK–1/3Time W), among which S6 is the current management method for field fertilization timing sequences, and S7 is the non N. The results showed that during the main growth stage, S5 accumulated more nitrate nitrogen (NO3–-N) and ammonium nitrogen (NH4+-N) content in soil between 20 and 40 cm, and accumulated more available phosphorus content in soil between 5–15 cm and 15–25 cm, S5 reducing N leaching and increasing P mobility. It is recommended to change the timing sequences management method of NPK fertilization for drip irrigation cotton to 1/4Time W–1/4Time PK–1/4Time N–1/4Time W, which is beneficial for plant nutrient absorption and utilization while reducing environmental pollution.

Recommended fertilization and timing of nitrogen fertilization influences the morphogenesis, structural characteristics, and production efficiency of Mombaça grass

This study aimed to evaluate whether different fertilization strategies influence the morphogenic, structural, and production characteristics of Megathyrsus maximus cv. Mombaça. The experimental design adopted was a randomized block design with a 4 × 3 factorial scheme having five replications. The treatments were as per the following fertilization recommendations: 5th Approach Guide (5AP), Pará Guide (PG), Nutrient Replacement (RP), and the Michaelis and Menten adapted model (MM), applied for three days after application of the nitrogen (N) source following defoliation (days 0, 3, and 6). The interaction between factors affected the following variables: leaf appearance rate (LAR), leaf elongation rate (LER), and leaf senescence rate (LSR). The highest stem elongation rate (SER) was observed for the 5AP recommendation treatment with N application on day 0 (0.113 cm). The highest leaf area index (LAI; 5.33) and tiller population density (TPD; 421.5 tillers m-2) were observed for the 5AP recommendation. The 5AP recommendation with N application on day 0 and on the sixth day after defoliation, and the MM recommendation with fertilization on day 0 showed the best LAR and LER, as well as a greater number of cycles and greater absolute values of leaf blade dry mass.

Interaction of the coupled effects of irrigation mode and nitrogen fertilizer timing on rice yield in different regions

AbstractThe production efficiency of water and nitrogen is affected by irrigation and the nitrogen rate. However, it is unclear whether there is a coupling effect of irrigation mode and the timing of nitrogen fertilizer application on rice. Therefore, a two‐year field experiment was conducted at two sites with varying cumulative temperatures from 2018 to 2019. The effects of irrigation mode and nitrogen fertilization timing on rice yield and related physiological parameters were examined in different regions. The results showed that sites with different average temperatures had different coupling effects of water and nitrogen on crop growth. The impact of irrigation mode on yield was greater than that of nitrogen fertilizer timing at the site with a 2800 °C annual cumulative temperature (Wanchang). Alternate wetting and drying irrigation increased yield, water production efficiency and nitrogen production efficiency by 8%–10%, 31%–37% and 8%–10%, respectively. In the site with a 2500 °C annual cumulative temperature (Longjing), the coupling effect of irrigation method and nitrogen fertilization timing was significant, and continuously flooded irrigation combined with nitrogen fertilizer (40%:30%:20%:10%) improved rice yield and production efficiency by delaying senescence of leaves and increasing dry matter translocation. The results indicate that combining temperature to explore the optimal coupling mode of irrigation and nitrogen is a promising cropping technique to improve crop productivity and production efficiency in northeastern China.

Soybean growth and nitrogen accumulation by soybeans in response to desiccation times of Urochloa brizantha pasture and nitrogen fertilization

The desiccation time of high-biomass pasture and nitrogen (N) fertilization of pasture and soybean can influence the soybean sowing, establishment and growth. The objective of this study was to evaluate how the time of desiccation of the preceding pasture of Urochloa brizantha cv. BRS Piatã, cultivated at three levels of N, and by the soybean N fertilization affect soybean growth and N accumulation. Three N rates (0; 150 and 300 kg ha-1), broadcast as urea on the U. brizantha pasture were evaluated separately in each N level, every one considered as one experiment. In each experiment, five times of pasture desiccation were evaluated (60; 45; 30; 15, and 1 day before soybean sowing) and two levels of soybean N fertilization: 30 kg ha-1 (urea) broadcast at sowing or without N fertilization. A randomized complete block design with five replications was used. Early desiccation of U. brizantha pasture favors the establishment of soybean and promotes an increase in biomass and N accumulation in the vegetative stages, however these differences are not observed during the grain filling, regardless the soybean N fertilization. The soybean yield was not influenced by the desiccation time. N fertilization with 30 kg ha-1 at sowing intensifies soybean growth at the vegetative phase, but after full flowering, there were no effects on biomass and grain yield, independently of the desiccation time.

Momento de adubação nitrogenada afeta as reservas radiculares de gramíneas tropicais

ABSTRACT Grass regrowth can reduce root mass, delaying reestablishment and grazing periods by reducing the nutrient absorption from the soil by plants. This study aimed to determine the optimal intervals for harvest and nitrogen fertilization in Urochloa brizantha cv. BRS Piatã and Megathyrsus maximus cv. BRS Quênia, as well as to investigate whether the flexibility of the fertilization time is related to the accumulation of water-soluble carbohydrates (WSC) and nitrogen in the roots. The experiment was conducted in a greenhouse, using a completely randomized design, with five treatments (nitrogen fertilization after harvest: 0, 2, 4, 6 and 8 days) and ten replicates. The nitrogen fertilization time linearly reduced the forage and root mass for the BRS Piatã, but had no effect on the BRS Quênia guinea grass. For the BRS Piatã, the WSC and starch concentrations in the roots showed a quadratic response, decreasing from harvest to day 2 and increasing until the day 8. However, the delayed fertilization led to a linear reduction in the root nitrogen content. The nitrogen fertilization time had a quadratic effect on the WSC concentration for the BRS Quênia roots. For the BRS Piatã, the nitrogen fertilization immediately after harvest improves the forage and root masses, WSC and nitrogen reserves. In contrast, the BRS Quênia exhibited a greater flexibility, concerning the nitrogen fertilization time. The interval between harvest and nitrogen fertilization is primarily depended on root mass, which influences the nitrogen accumulation in the roots.

Effect of Wheat Crop Nitrogen Fertilization Schedule on the Phenolic Content and Antioxidant Activity of Sprouts and Wheatgrass Obtained from Offspring Grains.

This work was aimed at investigating the effects of rate and timing of nitrogen fertilization applied to a maternal wheat crop on phytochemical content and antioxidant activity of edible sprouts and wheatgrass obtained from offspring grains. We hypothesized that imbalance in N nutrition experienced by the mother plants translates into transgenerational responses on seedlings obtained from the offspring seeds. To this purpose, we sprouted grains of two bread wheat cultivars (Bologna and Bora) grown in the field under four N fertilization schedules: constantly well N fed with a total of 300 kg N ha−1; N fed only very early, i.e., one month after sowing, with 60 kg N ha−1; N fed only late, i.e., at initial shoot elongation, with 120 kg N ha−1; and unfertilized control. We measured percent germination, seedling growth, vegetation indices (by reflectance spectroscopy), the phytochemical content (total phenols, phenolic acids, carotenoids, chlorophylls), and the antioxidant activity (by gold nanoparticles photometric assay) of extracts in sprout and wheatgrass obtained from the harvested seeds. Our main finding is that grains obtained from crops subjected to late N deficiency produced wheatgrass with much higher phenolic content (as compared to the other N treatments), and this was observed in both cultivars. Thus, we conclude that late N deficiency is a stressing condition which elicits the production of phenols. This may help counterbalance the loss of income related to lower grain yield in crops subjected to such an imbalance in N nutrition.

The effect of water and nitrogen on drip tape irrigated silage maize grown under arid conditions: Experimental and simulations

Nutrients and nitrate move to the boundary of the wetted zone under drip-tape irrigation (DTI) of row crops, so irrigation depth, wetted width, and irrigation frequency are the most important factors in managing the wetting front and keeping N in the root zone. Many farmers in arid regions who have changed their irrigation systems to DTI, but they are still applying N in two splits as they are used for surface and sprinkler irrigation. Crop models can be used to optimize the timing and amount of nitrogen fertilizer applied to minimize both N leaching and the amount of N remaining in the soil after harvest. The objectives of this study were to calibrate the Cropping System Model (CSM)-CERES-Maize for two maize hybrids and to evaluate the model under DTI with two different soil wetting widths. The single cross Hybrid 704 (SC704) grown in two experimental fields (Exp-1 and Exp-2) and the single cross Hybrid 606 (SC606) grown in one experimental field and two farmer fields (Exp-3, Ff-1 and Ff-2) were evaluated during three years (2016, 2017 and 2019). Plant traits including leaf area index (LAI), total biomass (TB), soil moisture (SM), nitrogen uptake (NU) and water productivity (WP) were measured. Soil NO3-N was measured at three distances from the planting row and three soil depths in Exp-1 and Exp-3 during two maize growth stages. The fraction of the wetted width (fw) along drip-tape was 70% in Exp-1% and 100% in Exp-3 (referred to as fw-70 and fw-100, respectively). The results showed good performance of the model for simulating TB and LAI with NRMSE < 21.9% for the two hybrids in the applied N fertilizer treatments. The accuracy of the simulation of SM and WP in fw-100 was better than that of fw-70. Simulated NO3-N followed the observed trend for fw-100, while model performance varied for the different irrigation and N levels in fw-70. Model accuracy for soil NO3-N prediction decreased for the high N fertilizer application under deficit irrigation management. These differences were related to the wetting pattern volume, the distribution of N in the soil profile, and accumulation of soil N under DTI. Overall, the model can simulate TB and NU with high accuracy, SM with good accuracy, and soil NO3-N with an acceptable accuracy under DTI. The accuracy of the model was also higher for the unlimited wetting width, as compared to the limited one. This study showed that the CSM-CERES-Maize model can be used for evaluation of nitrogen management practices for drip irrigated maize grown under arid conditions.

Impact of nitrogen fertilizer timing on nitrate loss and crop production in northwest Iowa.

In the U.S. Midwest, nitrate in subsurface tile drainage from corn (Zea mays L.)-soybean [Glycine max (L.) Merr.] systems is detrimental to water quality at local and national scales. The objective of this replicated plot study in northwest Iowa, performed in 2015-2020, was to investigate the influence of nitrogen (N) fertilizer timing on crop production and NO3 load in subsurface (tile) drainage discharge. Four treatments applied to corn included fall anhydrous ammonia with a nitrification inhibitor (F), spring anhydrous ammonia (S), split-banded urea at planting and mid-vegetative growth (SS), and no N fertilizer (0N). Across crops and years, NO3 -N concentration in subsurface drainage discharge was the same at 11.7mg L-1 for F and S applied anhydrous ammonia (AA). The NO3 -N concentration was statistically lower with SS urea (10mg L-1 ) than F and S, and 0N was lower than SS at 8.3mg L-1 . Average annual NO3 -N loads were not different between any treatments due to plot variability in drainage discharge. Corn responded to N application, with overall mean yield the same for F, S, and SS. There were no agronomic or water quality benefits for applying AA in spring compared with fall, where the F included a nitrification inhibitor and was applied to cold soils. Split-applied urea had a small positive water quality impact but no crop yield enhancement. This study shows that there were improvements to NO3 -N concentration in subsurface drainage discharge, but more nutrient reduction practices are needed than fertilizer N management alone to reduce nitrate load to surface water systems.

Soil carbon and nitrous oxide dynamics in corn (Zea mays L.) production under different nitrogen, tillage and residue management practices

Reducing tillage frequency and intensity and returning crop residues to the soil are two agricultural management practices to increase soil organic carbon (SOC). Timing and rates of nitrogen fertilizer, coupled with tillage methods and residue incorporation, can also influence nitrous oxide emissions. In this study, we used measured data from a long term (23 years) tillage and residue management experiment, under intensive grain corn production, together with the DNDC (DeNitrification-DeComposition) process-based model, to ascertain the most effective fertilizer and tillage management practices to reduce nitrous oxide emissions and nitrate leaching, and increase soil carbon stocks. The field experiment consisted of no-till [NT], reduced [RT], and conventional tillage [CT], with and without corn residue return. After calibration and validation, using field observed data, the DNDC model was run with 108 management scenarios (six N application rates, spring single N fertilization, spring split N fertilization and fall fertilization, three tillage practices and two residue-return options). N application rate was predicted to be a significant driver for corn yield, SOC sequestration, N2O emissions and nitrate leaching, indicating the need to identify a critical N rate to both optimize production and achieve sustainability goals. Split (vs. single) N application did not significantly affect corn yield, nitrate leaching, N2O emissions or SOC, while fall fertilization should be avoided due to greater nitrate leaching and higher N2O emissions as well as lower crop yield. Although stimulating N2O emissions, both NT and residue return are recommended for their ability to enhance SOC stocks. Results of this study can be used for policy development regarding carbon sequestration and GHG emissions for intensive grain cropping systems in the humid regions of North America.

By-Plant Prediction of Dry Matter Yields at Various Growth Stages of Maize Plants (Zea mays L.) Using Leaf Greenness Indicator in Climatic Conditions of Poland

Predicting yield at an early growth stage allows one to optimize the amount and timing of nitrogen fertilization to maximize crop yield. The aim of the study was to determine how different nitrogen doses would affect the nutrition of two maize varieties (Zea mays L.) with this element and their yields, and to demonstrate the potential of using the SPAD index as an early-stage predictor of dry matter yield (DMY) of maize biomass. The field experiment, with different pre- and post-sown N fertilizer doses, was conducted for two years in Poland. The two-factor experiment was set up in a randomized block design with three field replicates. There were four mineral fertilization variants: (I) 120 kg N·ha−1 without P and K fertilization, (II) 120 kg N·ha−1 + PK, (III) 160 kg N·ha−1 + PK, and (IV) 200 kg N·ha−1 + PK. The second-order factor was two stay-green maize varieties: Delitop (FAO 240) and Magitop (FAO 270). The mean values of the SPAD index of maize depended on the nitrogen dose. When the dose was increased from 120 kg·ha−1 to 200 kg·ha−1 with constant P and K fertilization, the value of the leaf greenness index increased significantly. The plants of both maize varieties fertilized with nitrogen at a dose of 120 kg N·ha−1 without P and K were characterized by the lowest values of the SPAD index, regardless of the year of the experiment. When the nitrogen dose was supplemented with P and K, the plants’ nutrition with nitrogen improved significantly. The values of the SPAD index in the maize plants of the variety Magitop were significantly greater than in the plants of the variety Delitop. The coefficients of correlation calculated for both maize varieties were highly significant at all measurement dates. Therefore, it is possible to conclude that the SPAD leaf greenness index can be used as an important, reliable, and non-invasive indicator for maize yield prediction. Nutrition of maize plants with nitrogen proved to be the main determinant of variability of the biomass yield. For this reason, it was the basis for the verification of individual mineral fertilization variants. The lack of phosphorus and potassium in the dose of mineral fertilizer limited the yield regardless of the variety, as compared to the variant that was optimally balanced with the nitrogen dose.

Nitrogen use efficiency, partitioning, and storage in cool climate potted Pinot Noir vines

Optimal timing of nitrogen (N) fertilizer to promote N use efficiency (NUE) in cool climate wine regions is largely unknown. One year-old potted Vitis vinifera L. (Vitaceae) cv. Pinot Noir vines were subjected to soil applied 15N-labelled calcium nitrate (5.5 atom%) fertilizer at four application timings (budbreak to fruit set, fruit set to veraison, veraison to harvest, or spread evenly across the growing season) over two growing seasons (2017/18 and 2018/19) at a rate of 12 g N vine−1. Annual vine parts (leaves and clusters) were collected at commercial harvest in both 2018 and 2019 and the remaining vine was destructively harvested during winter dormancy. Vines were separated into organs (leaves, clusters, shoot, trunk, and roots) and organ dry matter was determined before samples were ground into a fine powder to determine total N percentage and 15N atom percentage using flash combustion isotope ratio mass spectrometry (varioPYRO cube coupled to Isoprime100 mass spectrometer). Compared to the average values obtained from the other treatments, the veraison to harvest treatment significantly reduced whole vine dry matter by 39.1% and vine NUE by 42.1%. Yield was also reduced by 12.9% compared to the budbreak to fruit set treatment. NDF, defined here as the proportion of N within the vine (or vine organ) that was derived from fertilizer N, and overall vine total N content was lower in the veraison to harvest treatment due to the reduction of root and shoot NDF content. This suggests that for young, actively growing vines in cool climates, limiting N applications until veraison is inefficient and ineffective. No significant differences in NUE, N partitioning or N storage were observed between the other fertilizer N application timings.

Laboratory germinability and germination energy of spelt grain depending on fertilization and storage

Spelt is a promising crop for processing, as valuable micronutrients are evenly distributed in its grain, while in modern wheat bread varieties they are concentrated in the hull, aleurone layer and germ. Its proteins contain more gliadins and fewer glutenins, making gluten weak, but better digestible in the human body.&#x0D; Purpose and objectives: to assess the germinability and germination energy of spelt depending on the types, doses and timing of nitrogen fertilization and storage period.&#x0D; Materials and methods. The study was conducted in the Laboratory of Evaluation of Grain and Grain Product Quality of the Chair of Grain Storage and Processing Technologies of Uman National University of Horticulture. We studied winter spelt variety Yevropa created by hybridization of Triticum aestivum L. with Triticum spelta L. Fertilizers were ammonium nitrate, ammonium sulfate, granular superphosphate, and potassium chloride.&#x0D; Results and discussion. The study found that before storage the germination energy of grain was 87–90% depending on fertilization. Nitrogen fertilizers significantly increased this indicator. When grain was stored for 30 and 90 days, the germination energy was the highest and amounted to 98–99%. Longer storage significantly decreased this parameter. It was the lowest after P60K60 application: 95%, 92% and 87% when grain was stored for 180, 270 and 360 days, respectively.&#x0D; Before and after 30- and 90-days storage of spelt grain, this parameter amounted to 99% and regardless of fertilizers. The lowest laboratory germinability was observed after 1-year storage of grain (81–84% depending on fertilizers). This indicator was the highest with P60 + N120, amounting to 84%, and the lowest without fertilizers or with N60S70 + N60.&#x0D; Conclusions. The germination energy of spelt grain was found to be the highest after 30- to 180-day storage (96-99%). This indicator was most affected by nitrogen fertilizers. After 360-day storage, the germination energy reduced to 87–91% depending on the type and timing of nitrogen fertilization. The laboratory germinability of spelt grain of 97–99% maintained from harvesting to storage day 180. When spelt grain was stored in sealed containers without temperature control, this indicator gradually decreased to 81–84% for 360 days of storage, depending on fertilizers

Timing of nitrogen application and cover crops on upland rice economic viability

Abstract: The objective of this work was to evaluate the economic viability and competitiveness of upland rice (Oryza sativa), compared with flooded rice, in a system with different nitrogen fertilization timing and cover crops in Southeastern Brazil. The treatments consisted of upland rice grown under Urochloa brizantha or Urochloa ruziziensis straw, with the following fertilization: T, 30 kg ha-1 N at rice sowing + no extra N supply (0 kg ha-1); C, 30 kg ha-1 N at rice sowing + 90 kg ha-1 N at rice tillering; A2, 30 kg ha-1 N at rice sowing + 90 kg ha-1 N one day before rice sowing; and A1, 30 kg ha-1 N at rice sowing + 90 kg ha-1 N in the living cover crops. Total operating cost, gross revenue, operating profit, profitability index, and equilibrium price were determined. Upland rice results in a monetary gain for the farmer similar to that of flooded rice when nitrogen is added, regardless of fertilization timing. Under rainfall deficit conditions, upland rice sown on U. brizantha straw shows higher profitability rates than when sown on U. ruziziensis. When there is a possibility of rainfall deficit, U. brizantha, as a cover plant, results in a greater economic security for upland rice producers.

Nitrogen Fertilizer Timing and Phosphorus and Potassium Fertilization Rates for Established Endophyte-Free Tall Fescue: Year 3

Nitrogen Fertilizer Timing and Phosphorus and Potassium Fertilization Rates for Established Endophyte-Free Tall Fescue: Year 3

Timing, Source, and Placement of Nitrogen Fertilizer Increases Wheat Yield and Protein Content in High Yielding Environments

Timing, Source, and Placement of Nitrogen Fertilizer Increases Wheat Yield and Protein Content in High Yielding Environments

Nitrous oxide emissions and nitrogen use efficiency in wheat: Nitrogen fertilization timing and formulation, soil nitrogen, and weather effects

AbstractImproving N fertilization in croplands could minimize soil emissions of nitrous oxide (N2O) and mitigate climate change. This study investigated the effects of spring vs. fall N applications of conventional vs. enhanced‐efficiency N fertilizers (EENFs) on N2O emissions and N use efficiency in spring wheat (Triticum aestivum L.) over 2.5 yr in Alberta, Canada. Fertilizers were anhydrous ammonia and urea and the EENF formulations included urease and nitrification inhibitors and a polymer coating. We measured a fertilizer N2O emission factor of 0.31 ± 0.04%. Irrespective of N fertilizer and timing options peak N2O emissions were evident following soil thawing and major rainfalls. Because most of the annual N2O emissions were associated with soil thawing, spring‐applied N emitted half the N2O of the fall‐applied N during the second study year (P &lt; .001). Conversely, the opposite was observed for the first study year when overall N2O emissions were 36% larger for spring‐ than fall‐applied N (P = .031) as major rainfalls occurred shortly after the spring N fertilization. Nevertheless, within this first study year, EENFs significantly reduced N2O emissions (by 26% on average; P = .019), with a tendency for 11% higher grain yield across springtime EENFs than for conventional fertilizers. Concomitantly, spring‐applied N doubled the fertilizer N recovery efficiency in the same year (P = .023). The soil at the study site inherently had high N availability (NH4 and NO3) and this probably moderated the beneficial effects of EENFs on N2O emissions and grain yields. Results suggest that spring EENFs can mitigate the risk for N2O emissions while sustaining high yields even under scenarios with high availability of native soil N.