Type Of Nitrogen Fertilizer Research Articles

Assessment of Nitrogen Volatilization and Greenhouse Gas Emissions from Urea with N-stabilizer in a Productive Oil Palm Plantation (Elaeis guineensis Jacq.)

Nitrogen fertilization plays a crucial role in supporting plant growth. However, nitrogen in the soil can be lost through rainwater leaching. To address this issue, the concept of fertilizing N-stabilizer-coated urea was proposed. The aim is to reduce nitrogen loss on the field due to vaporization and minimize greenhouse gas (GHG) emissions. The study was conducted to assess the effectiveness of this N-stabilizer-coated urea in reducing nitrogen loss through vaporization, improving GHG emissions, and its impact on plant growth and leaf quality. The research was conducted at IPB-Cargill Jonggol, Bogor, West Java, oil palm education and research station from August 2021 to March 2022. The experimental design employed a completely randomized block design. The fertilizer treatments included four types of nitrogen fertilizers: urea (46% N), coated urea with N-stabilizer (46% N), ZA (21% N), and NPK (15-15-15, 15% N). Additionally, a control treatment without any fertilizer application was included. All treatments were replicated three times. Data analysis was done using the SAS (Statistical Analysis System) 9.0 program. The F-test was conducted, followed by DMRT (Duncan Multiple Range Test) advanced tests at a 5% error level. The results revealed that urea with N-stabilizer fertilization significantly reduced NH3-vaporization by 53% in the first week compared to the application of normal urea. NH3-vaporization level from ZA and NPK was < 1% compared to urea application. Field application of urea with N-stabilizer showed no significant difference in greenhouse gas emission (GHG) compared to the other nitrogen fertilizer types. The GHG values ranged from 7.10 to 7.29 g CO2-e.m-2 per day. The use of N-stabilizer-coated urea could be an effective approach to minimize nitrogen loss through vaporization and reduce greenhouse gas emissions while maintaining comparable results to other nitrogen fertilizer types in terms of GHG emissions on the field.

Combination of nitrogen and organic fertilizers reduce N2O emissions while increasing winter wheat grain yields and quality in China

Wheat grain yields, quality, and nitrous oxide (N2O) emissions were controlled through the type and application rate of nitrogen (N) fertilizer. Here, we investigated the optimal management of N fertilization by examining the combined effects of organic and N fertilizers on wheat yields, quality, and N2O emissions. Field trials under six treatments were located on campus farms at Anhui Science and Technology University, including farmer’s common practice (270 kg N ha-1, N270), 2/3 reduction in N270 (90 kg N ha-1, N90), organic fertilizer with equal N270 (OF270), 2/3 reduction in OF270 (OF90), 4/5 reduction OF270 + 1/5 reduction N270 (20% OF270 + 80% N270), and 4/5 reduction OF90 + 1/5 reduction N90 (20% OF90 + 80% N90) were applied to winter wheat. The plots were arranged in a randomized complete block experimental design. The N2O emissions were quantified under different fertilization measures in the peak wheat growing season during sowing, jointing, and grain filling stages, respectively. Compared with N270 and N90 treatments, N2O emissions were significantly decreased by 18.6% and 27.2%, respectively, under 20% OF270 + 80% N270% and 20% OF90 + 80% N90 (p < 0.05). Further, N2O emissions in N270 were increased by 50.8% relative to N90. Wheat yields increased significantly under 20% OF90 + 80% N90 by 27.6% (N270) and 16.4% (N90), and were considerably enhanced under 20% OF270 + 80% N270 by 40.6% (N270) and 12.7% (N90) in contrast to OF270 and N270 (p < 0.05). Compared with N90, the content of wet gluten, protein and starch under 20% OF90 + 80% N90 treatment significantly increased by 7.7%, 13.8% and 7.9%, and enhanced by 7.6%, 4.8%, 8.0% relative to OF90, respectively (p < 0.05). The starch content increased significantly by 2.0%, whereas the settlement value decreased considerably by 2.9% under 20% OF270 + 80% N270 (p < 0.05), and there was no notable difference in the wet gluten and protein contents (p > 0.05). Our findings indicated that organic fertilizer mixed with N fertilizer can effectively reduce N2O emissions, increase both the grain yields and quality in wheat field compared with N fertilizer alone.

Co-application effects of rice husk biochar and different types of nitrogen fertilizers on rice yield, yield components, and nitrogen use efficiency

The Nitrogen (N) recovery index in rice paddy soils has never been exceeded by more than 30%, regardless of using proven fertilizer management strategies and amounting to significant N being out of rice plant use. Biochar application and the newly released N biofertilizers (singly or in combination) increase the N use efficiency by increasing the soil nutrient retention capacity. Therefore, a two-year pot experiment was conducted to explore the effects of the co-application of rice husk biochar and nitrogen fertilizers on rice yield, yield components, and nitrogen use efficiency indexes. The applied treatments were rice husk biochar at three levels (0, 20, and 40 tha−1) and N fertilizers at three levels (0, chemical (Urea), and N-biofertilizer). The most effective combination treatments (200 kg N ha−1 in source of urea plus 40 tha−1 rice husk biochar) significantly (p ≤ 0.01) increased the grain yield (2.38 times), straw and biological yield (2.83 and 2.62 times, respectively), N content of soil N (59%), nitrogen uptake efficiency (2.92 times), and nitrogen internal efficiency (59%), whereas, nitrogen recovery efficiency decreased by about 52%. Moreover, the maximum increase in N content of grain and harvest index was recorded at combination application of 20 tha−1 biochar plus urea by about 48 and 15%, respectively. It can be concluded that the co-application of rice husk biochar and N fertilizers has substantial advantages over their single applications in terms of N fertilizer recovery, N uptake. Thus, it might be an effective way to enhance rice yield.

The Effect of Paclobutrazol and Types of Nitrogen (N) Fertilizer on The Growth and Yield of Long Bean (Vigna sinensis L.)

Long bean is the one of the most widely consumed vegetables both fresh and processed. The market demand for long beans is rising, but their production remains limited. This study aims to investigate how different concentrations of paclobutrazol and various types of nitrogen fertilizers affect the growth and yield of long bean plants. The research was conducted in Dander Village, Dander District, Bojonegoro Regency, East Java. The study employed a factorial Randomized Block Design (RBD) with two factors: the concentration of paclobutrazol (P0 = control, P1 = 150 ppm, P2 = 200 ppm, P3 = 250 ppm) and the type of nitrogen fertilizer (N0 = NPK control, N1 = Urea, N2 = ZA, N3 = KNO3). Variables to observed included plant length, number of leaves, flowering age, number of pods, pod weight, number of seeds, and fruit set. The results showed that the combination of 150 ppm paclobutrazol and KNO3 nitrogen fertilizer produced the best results in terms of the fastest flower emergence at 29 days after planting (HST) and the highest pod weight of long beans at 43.00 grams per plant. Keywords: Paclobutrazol, Various Nitrogen Fertilizers, Growth, Yield, Long Beans (Vigna sinensis L.)

The electrochemical mechanism of biochar for mediating the product ratio of N2O/(N2O + N2) in the denitrification process

The biochar electrochemical properties and surface functional groups significantly impact N2O production and reduction during denitrification process. However, its effects on N2O emissions during the denitrification process and its electrochemical mechanisms remain unclear. The study examined the impact of pristine and oxidized biochar combined with two types of nitrogen fertilizers on the N2O/(N2O + N2) ratio and N2O emissions in an incubation experiment with seven treatments: (1) CK (no application of chemical fertilizer); (2) N1 (applying (NH4)2SO4); (3) N1B ((NH4)2SO4 + pristine biochar); (4) N1BO ((NH4)2SO4 + oxidized biochar); (5) N2 (applying KNO3); (6) N2B (KNO3 + pristine biochar); (7) N2BO (KNO3 + oxidized biochar). The study found that in comparison with applying nitrogen fertilizer alone, combining pristine biochar decreased soil N2O concentration by 7.1 %–85.8 %, while combining oxidized biochar increased it by 15.7 %–125.6 %. Applying pristine biochar reduced N2O/(N2O + N2) ratio by 10.4 %–86.2 %, whereas applying oxidized biochar increased it by 12.9 %–121.6 %. The application of pristine biochar increased the nosZ gene abundance and decreased the (nirS + nirK)/nosZ ratio, which contributed to reducing N2O to N2. Compared with oxidized biochar, the oxygen-containing functional groups of pristine biochar decreased by 46.6 %, and it possessed a higher specific surface area (23.01 m2 g−1) and electrical conductivity (0.003 mS cm−1). The correlation analysis showed that DOC and inorganic nitrogen were the key environmental factors affecting N2O emissions. Additionally, the electrical conductivity, specific capacitance, and oxygen-containing functional groups of the biochar were identified as the main factors driving N2O emissions. The SEM analysis suggested that the indirect influence of biochar electrochemical properties on N2O emissions was greater than its direct influence. Our work provides fresh perspectives on reducing soil N2O emissions and establishes a theoretical foundation for the subsequent preparation of biochar materials with enhanced N2O reduction capabilities.

Interactive effects of soil salinity and nitrogen fertilizer types on nitrous oxide and ammonia fluxes

Soil salinization, impaired by climate change and poor management practices, poses a global threat, particularly in arid and semi-arid regions, leading to significant land degradation. This study aims to investigate the effects of different nitrogen (N) fertilizer sources (urea, ammonium-sulfate, and biogas waste) on CO2, N2O, and NH3 emissions and soil enzyme activities in two soil types varying in salinity level (non-saline: EC = 1.15 dS m−1, and saline: EC = 35.80 dS m−1) in a robotized continuous-flow soil incubation system. Our results showed a sharp increase in N2O and CO2 emissions (up to 0.51 ± 0.02 g N2O-N ha−1 day−1, 28.1 ± 3.9 kg CO2-C ha−1 day−1) in non-saline soils following soil rewetting, attributed to bacterial denitrification. However, this pattern was not observed in saline soils, suggesting that salinity causes partial inhibition to the regeneration of soil organic matter mineralization and denitrification processes after rewetting. Although salinity did not alter the overall cumulative N2O losses in any fertilizer treatment, it significantly delayed the evolution of N2O peak during the incubation period. On the other hand, NH3 volatilization was significantly higher in N-fertilized saline soils compared to non-saline soils (241% and 157% in ammonium-sulfate and biogas waste treatments, respectively), except for urea treatment, likely due to the decrease in nitrification rates. Furthermore, the study clearly showed lower soil enzyme activity levels for both nitrate reductase and urease activity. Interestingly, the lowest NH3 emissions were measured in urea treatment in both soils. Overall, our findings highlight the complex interplay between soil salinity, nitrogen fertilizer sources, and microbial processes, significantly influencing gaseous nitrogen emissions and N cycling in agricultural soils. Identifying the specific fertilizer treatments that minimize or maximize gaseous nitrogen losses in varying soil salinity, may guide the selection of appropriate fertilization strategies for farmers and policymakers to mitigate environmental impacts of fertilizer use during agricultural production.

Effects of nitrogen fertilization on the fate of high-risk antibiotic resistance genes in reclaimed water-irrigated soil and plants

High-risk antibiotic resistance genes (ARGs) in reclaimed water-irrigated soil pose a potential threat to ecosystem and human health. Inorganic fertilization – including with nitrogen, a key ingredient in agricultural production – may affect the ARG profile in soil. However, little is known about nitrogen fertilization's influence on ARGs profiles in the soil–plant system. This study investigated the effects of different nitrogen fertilizer types (CO(NH2)2, NO3–-N (NaNO3) and NH4+-N (NH4HCO3)) and different nitrogen fertilizer application rates (low, medium, high) on the distribution of high-risk ARGs in reclaimed water-irrigated soil and plants using quantitative PCR, high-throughput sequencing and metagenomic sequencing. Soil microcosms results revealed that nitrogen fertilization significantly affected the pattern of high-risk ARGs in soil, and also affected high-risk ARGs abundance and transfer capacity in plants. Compared with nitrogen fertilizer application rate, nitrogen fertilizer types significantly contributed to enhancing the soil resistome, with the order of CO(NH2)2 > NO3–-N ≈ NH4+-N. The medium application of NO3–-N and NH4+-N significantly reduced high-risk ARGs abundance in the leaf endophyte. Bacterial community mainly drove the variation of ARGs in nitrogen-fertilized soil–plant system, and class I integron and metal resistance genes (MRGs) also had direct effects on these high-risk ARGs. A similar high-risk ARGs pattern was also found in field plot experiments, and several dangerous pathogens were observed as the main high-risk ARGs potential hosts in nitrogen-fertilized soil. Based on an economic assessment, application of NH4+-N (NH4HCO3) could reduce costs by $1,312.83 ha−1 compared with NO3–-N (NaNO3). These results showed that the more important role of nitrogen type might be an effective and economical way to control high-risk ARGs spread in soil–plant system under reclaimed water irrigation.

Annual consumption and types of synthetic nitrogen fertilizers: Ammonia emission indicators for mitigation strategies in the European Union

Anthropogenic ammonia (NH3) emissions are primarily derived from agricultural activities. NH3 emissions from synthetic nitrogen (N) fertilizers are associated with the annual consumption of various N fertilizers. In this study, the annual consumption of different types of synthetic N fertilizers in the EU countries, derived from the database of the International Fertilizer Association, was analyzed, and the implementation of mitigation measures for NH3 emissions at the national level was assessed. NH3 emissions were estimated using the emission factors of different N fertilizers in cool, temperate and hot climates, and low- and high-pH soils, as the European Environment Agency proposed. The results revealed that the annual consumption of various synthetic N fertilizers (average values from 2016 to 2020) varied markedly in different EU countries. France, Germany, Poland, Spain, and the United Kingdom had the largest annual consumption of synthetic N fertilizers. NH3 emissions from urea-based fertilizers are the highest in most EU countries. The annual NH3 emissions were associated with the type of synthetic N fertilizer consumed. For example, although the annual synthetic N fertilizer consumption in Germany was 38% and 41.5% higher than those in Spain and Italy, the annual NH3 emissions in Germany were 63% and 20% lower than those in Spain and Italy, respectively, due to the high proportion of urea-based fertilizers with the highest emission factor among the synthetic N fertilizers in Spain and Italy. Thus, mitigation strategies should be tailored to specific types of N fertilizers with high emission factors and proportions to minimize NH3 emissions. Since the NH3 emissions from urea-based fertilizers are the highest in the EU countries, especially in the top five countries, we recommend the addition of urease inhibitors to urea fertilizers as one important strategy for mitigating NH3 emissions.

Optimization of N Fertilizer Type and Ridge–Furrow Ratio to Improve Resource Use Efficiency and Grain Yield of Rain-Fed Winter Wheat in Loess Plateau, China

Ridge and furrow plastic mulch (RFPM) and nitrogen (N) application are effective strategies for improving crop productivity in China’s Loess Plain. However, it is not clear how the ridge–furrow ratio and nitrogen fertilizer type (NT) affect the use of water, nitrogen, heat, and radiation resources for the enhancement of rain-fed wheat production. Two nitrogen fertilizer types (traditional urea (TU) and controlled-release urea (CRU)) and four planting patterns (conventional flat planting (F) and the RFPM system of 20 cm ridges with 40 cm furrows (R2F4), 40 cm ridges with 40 cm furrows (R4F4), and 60 cm ridges with 40 cm furrows (R6F4)) were tested from September 2018 to June 2021 during the winter wheat growing season. It was found that the RFPM system can increase soil thermal time (TTsoil) from 41.0 to 152.1 °C d compared to the F. RFPM system thermal effect, which reduced the vegetative growth period and prolonged the reproductive growth period for 2 to 7 days, which promoted an increase in the leaf area index (LAI) and final dry matter (DM) accumulation. These significantly increased the grain yield (GY) in the RFPM system by 51.6–115.2% and enhanced the thermal time use efficiency (TUE) by 48–99.5%, water productivity (WP) by 37.4–76.3%, radiation use efficiency (RUE) by 16.3–34.4%, and partial factor productivity of nitrogen (PFPN) by 51.6–115.2% compared to F. Although a high ridge and furrow ratio in combination with CRU increased the GY and resource use efficiency, it also exacerbated the soil water depletion, especially in the soil layer between 40 and 140 cm. Overall, CRU combined with the 40 cm ridge and 40 cm furrow RFPM system maximized resource efficiency and increased wheat production on China’s Loess Plateau.

Impact of nitrogen fertilizer type and application rate on growth, nitrate accumulation, and postharvest quality of spinach.

A balanced supply of nitrogen is essential for spinach, supporting both optimal growth and appropriate nitrate (NO3 -) levels for improved storage quality. Thus, choosing the correct nitrogen fertilizer type and application rate is key for successful spinach cultivation. This study investigated the effects of different nitrogen (N) fertilizer type and application rates on the growth, nitrate content, and storage quality of spinach plants. Four fertilizer types were applied at five N doses (25, 50, 200, and 400 mg N kg-1) to plants grown in plastic pots at a greenhouse. The fertilizer types used in the experiment were ammonium sulphate (AS), slow-release ammonium sulphate (SRAS), calcium nitrate (CN), and yeast residue (YR). Spinach parameters like Soil Plant Analysis Development (SPAD) values (chlorophyll content), plant height, and fresh weight were measured. Nitrate content in leaves was analyzed after storage periods simulating post-harvest handling (0, 5, and 10 days). The application of nitrogen fertilizer significantly influenced spinach growth parameters and nitrate content. The YRx400 treatment yielded the largest leaves (10.3 ± 0.5 cm long, 5.3 ± 0.2 cm wide). SPAD values increased with higher N doses for AS, SRAS, and CN fertilizers, with AS×400 (58.1 ± 0.8) and SRAS×400 (62.0 ± 5.8) reaching the highest values. YR treatments showed a moderate SPAD increase. Fresh weight response depended on fertilizer type, N dose, and storage period. While fresh weight increased in all fertilizers till 200 mg kg-1 dose, a decrease was observed at the highest dose for AS and CN. SRAS exhibited a more gradual increase in fresh weight with increasing nitrogen dose, without the negative impact seen at the highest dose in AS and CN. Nitrate content in spinach leaves varied by fertilizer type, dose, and storage day. CNx400 resulted in the highest NO3 - content (4,395 mg kg-1) at harvest (Day 0), exceeding the European Union's safety limit. This level decreased over 10 days of storage but remained above the limit for CN on Days 0 and 5. SRAS and YR fertilizers generally had lower NO3 - concentrations throughout the experiment. Storage at +4 °C significantly affected NO3 - content. While levels remained relatively stable during the first 5 days, a substantial decrease was observed by Day 10 for all fertilizers and doses, providing insights into the spinach's nitrate content over a 10-day storage period. For rapid early growth and potentially higher yields, AS may be suitable at moderate doses (200 mg kg-1). SRAS offers a more balanced approach, promoting sustained growth while potentially reducing NO3 - accumulation compared to AS. Yeast residue, with its slow nitrogen release and consistently low NO3 - levels, could be a viable option for organic spinach production.

Integrated Management of Slow- release Nitrogen Fertilizer Types and Rates for Wheat Production under Middle Nile Delta Soil Conditions

Integrated Management of Slow- release Nitrogen Fertilizer Types and Rates for Wheat Production under Middle Nile Delta Soil Conditions

The Effect of Nitrogen Fertilizer Types and Doses on Cob Yield and Some Quality Characteristics in Sweet Corn (Zea mays saccharata Sturt.)

Araştırmada azotlu gübre çeşitleri [Nitropower 33, üre ve UTEC] ve dozlarının (15, 20 ve 25 kg da-1) şeker mısırında verim ve kalite özelliklerine etkisi belirlenmiştir. Çalışma şans bloklarında bölünmüş parseller deneme planına göre kurulmuştur. Ana parsellere gübreler, alt parsellere ise dozlar yerleştirilmiştir. Çalışmada, gübre çeşitlerinin taze koçan verimine (kavuzlu ve kavuzsuz), ham kül oranına, toplam çözülebilir şeker miktarına; dozların ise ham protein oranına, ham kül oranına ve toplam çözülebilir şeker miktarına etkisi istatistiksel olarak önemli olduğu belirlenmiştir. Elde dilen sonuçlara göre, en yüksek kavuzlu ve kavuzsuz taze koçan verimi, yavaş salınımlı gübre çeşidinde (UTEC) ve 20 kg da-1 gübre uygulamasında tespit edilmiştir. Azot dozunun artmasıyla özellikle toplam çözülebilir şeker miktarı, ham protein ve ham kül oranı da artmıştır.
 Sonuç olarak, Vega F1 tatlı mısır çeşidinde yavaş salınımlı gübre uygulamasının (UTEC) verim artışı yanında, kalite (ham protein ve toplam çözülebilir şeker miktarı gibi) üzerinde de olumlu etki yaptığı belirlenmiştir.
 Sonuç olarak, Vega F1 tatlı mısır çeşidinde yavaş salınımlı gübre uygulamasının (UTEC) verim artışı yanında, kalite (ham protein ve toplam çözülebilir şeker miktarı gibi) üzerinde de olumlu etki yaptığı belirlenmiştir.

Effect of different doses and application types of nitrogen fertilizer on some physiological and agronomical parameters of bread wheat genotypes

Wheat (Triticum aestivum L.) is an important food crop in many regions of the World. Wheat production in the world depends significantly on the application of nitrogen fertilizer in the right amount and time. We studied the effect of different doses (0, 90, 120, 150kgN/ha) and application types (full, split) of nitrogen (N) fertilizer on some physiological (gas exchange, pigments content, relative water content, stem dry mass), agronomical (aboveground biomass, number of stems per unit area, grain yield) parameters of 3 bread wheat genotypes. Increasing the dose of nitrogen fertilizer had a positive effect on the parameters studied, with the exception harvest index. Full application of N was more effective. The response of the Gobustan and Gyrmyzy gul 1 genotypes to the use of N fertilizer was more strict. Keywords: Wheat, nitrogen fertilizer, physiological and agronomical parameters, pigments, grain yield

Controlled-Release Nitrogen Mixed with Common Nitrogen Fertilizer Can Maintain High Yield of Rapeseed and Improve Nitrogen Utilization Efficiency.

Field experiments were conducted to study the effects of different proportions of controlled-release nitrogen fertilizer mixed with quick-acting nitrogen fertilizer on the yield and nitrogen utilization efficiency of direct-seeding rapeseed. Using a conventional nitrogen application rate of 180 kg ha-1 as a control, a total of 5 types of available nitrogen fertilizers and different proportions of controlled-release nitrogen fertilizers were mixed for fertilizer treatment. The proportion of available nitrogen fertilizer used was 135 kg ha-1, and the addition ratios of the five types of controlled-release nitrogen fertilizers were 0%, 30%, 50%, 70%, and 100%, respectively (i.e., the proportion of controlled-release nitrogen to the total nitrogen application amount). These ratios were represented as N135R0, N135R1, N135R2, N135R3, and N135R4, respectively. The results showed that there was no significant difference in the number of pods per plant, the number of seeds per pod, or the grain yield under the treatment of controlled-release nitrogen fertilizer mixed with quick-acting nitrogen fertilizer for proportions of 30-50% (N135R1~R3) when compared with the control, and a stable yield was achieved. Mixing controlled-release nitrogen fertilizer under reduced nitrogen application can significantly improve the apparent utilization rate of rapeseed nitrogen fertilizer, but it first increases and then decreases with the increase of the controlled-release nitrogen mixing ratio, reaching its highest under the N135R2 treatment. The agronomic utilization efficiency and partial productivity of nitrogen fertilizer first increased and then decreased with the increased proportion of controlled-release nitrogen, and both reached their highest utilization with the N135R2 treatment. The mixed treatment of controlled-release nitrogen did not affect soil urease activity, but significantly increased soil sucrase activity. The mixed treatment of controlled-release nitrogen also increased soil microbial biomass nitrogen and carbon content. Especially in the flowering stage, the soil microbial biomass nitrogen and carbon content was significantly higher under a controlled-release nitrogen mixing ratio of 30-50%. At the same time, it had a similar effect on soil inorganic nitrogen content. Therefore, a controlled-release nitrogen mixing treatment provided sufficient nitrogen for the key growth period of rapeseed. Under the condition of reducing the amount of nitrogen fertilizer by 25% based on the amount of nitrogen fertilizer applied to conventional rapeseed, the application of controlled-release urea mixed with common nitrogen fertilizer mixed at a ratio of 30-50% can be an effective way to maintain grain yield levels and improve nitrogen utilization efficiency.

Functional relationships between yield of maize (Zea mays L.) and its components

Summary A field experiment was carried out in the years 2017–2019 on the fields of the Experimental Station in Chrząstowo, belonging to the Research Centre for Cultivar Testing in Słupia Wielka. It was carried out for 3 years in the same split-plot design with 2 experimental factors in 3 field replicates. The following factors were studied: A – 1st order factor – maize variety: A1 – ES Bombastic (FAO 230-240) – single cross hybrid (SC), A2 – ES Abakus (FAO 230-240) – three-way cross hybrid (TC, stay-green), A3 – ES Metronom (FAO 240) – single cross hybrid (SC, stay-green + roots power). B – 2nd order factor – type of nitrogen fertilizer: B1 – control (without N application), B2 – ammonium nitrate, B3 – urea, B4 – ammonium nitrate + N-Lock, B5 – urea + N-Lock, B6 – Super N-46, B7 – UltraGran stabilo. In this study, we investigated whether there was a functional relationship between maize grain yield and ear number, TSW (thousand-seed weight), and seed number per ear. Additionally, we investigated whether there was a functional relationship between maize grain yield and ear number, TSW, and seed number per ear for each type of fertilization in a given study year, as well as for each type of fertilization regardless of year.

Effect of co-application of straw and various nitrogen fertilizers on N2O emission in acid soil

In order to explore the alteration of N transformation and N2O emissions in acid soil with the co-application of straw and different types of nitrogen (N) fertilizers, an incubation experiment was carried out for 40 days. There are totally five treatments in the study: (a) without straw and N fertilizer (N0), (b) straw alone application (SN0), (c) straw with NH4Cl (SN1), (d) straw with NaNO3 (SN2), and (e) straw with NH4NO3 (SN3). N2O emissions, soil physicochemical properties, and abundance/activity of ammonia-oxidizing archaea (AOA) were measured. The results showed that the combined application of straw and N enhanced N2O emissions, particularly, SN2 and SN3 treatments. Moreover, the soil pH was lower in co-application treatments and the average decreasing rate was 9.69%. Specially, the pH was lowest in the SN1 treatment. The results of correlation analysis indicated a markedly negative relationship between pH and N2O, as well as a negative relationship between pH and net mineralization rate. These findings suggest that pH alteration can affect the N transformation process in soil and thus influence N2O emissions. In addition, the dominant AOA at the genus level in the SN2 treatment was Nitrosopumilus, and Candidatus nitrosocosmicus in the SN3 treatment. The reshaped AOA structure can serve as additional evidence of the changes in the N transformation process. In conclusion, as the return of straw, the cumulation of N2O from arable acid soil depends on the form of N fertilizer. It is also important to consider how N fertilizer is applied to reduce the possibility of N being lost in the soil as gas.

Effects of Combined Application of Biochar and Different Types of Nitrogen Fertilizers on Rapeseed Root Growth and Properties of Purple Soil in Southwest China

To demonstrate the effects of combined application of biochar and different types of nitrogen fertilizers on the growth of plant roots and on purple soil properties such as soil nutrients, soil carbon content and soil respiration, a 206-day greenhouse pot experiment with rapeseed was conducted. Three types of nitrogen fertilizer were used: urea (UR), controlled-release urea (RU), a mixture of 60% urea and 40% controlled-release urea (40% RU), and biochar was added at mass fractions of 0% (C0), 2% (C1) and 4% (C2), with a control treatment (CK) without nitrogen fertilizer and biochar. The results showed that biochar significantly improved soil nutrient status, with the best effect observed when 40%RU was co-applied with biochar. The addition of biochar significantly increased soil total organic carbon (TOC) and particulate organic carbon (POC). Soil respiration increased with increasing biochar application, and the combination of 2% biochar and 40% RU showed a reduction in carbon emissions compared to the UR and RU treatments. The number of rapeseed root tips (NT), forks (NF) and crossings (NC) increased significantly with the addition of biochar, and the combination of biochar and 40% RU was more beneficial for root growth and development than RU and UR. Considering the improvement in soil nutrition, increased soil organic carbon content, reduced carbon emissions, and enhanced rapeseed growth and development, the co-application of 2% biochar and 40% RU is recommended for large-scale application in rapeseed cultivation in the hilly purple soil of southwest China.

Nutrient runoff loss from saline-alkali paddy fields in Songnen Plain of Northeast China via different runoff pathways: effects of nitrogen fertilizer types.

The application of nitrogen (N) fertilizer aggravates the nutrient runoff loss from paddy, causing serious agricultural non-point source pollution, and leading to a serious decline in water quality. The global area of saline-alkali paddy has expanded, but the response of nutrient loss via runoff to N-fertilizer applications in saline-alkali paddy is still unclear. This study conducted a 147-day field experiment to evaluate the nutrient runoff loss from saline-alkali paddy with different N-fertilizer application strategies in Songnen Plain of Northeast China. Regardless of N-fertilizer types, the nutrient loss via rainfall runoff in the entire rice-growing season was significantly (p < 0.05) higher than that via artificial drainage. The N and phosphorus (P) concentrations in runoff water were correlated with salinity and alkalinity. Especially, pH had a significant positive correlation with total-P (TP) (r = 0.658, p < 0.01). In the entire rice-growing season, the TN runoff losses in urea (U), microbial fertilizer (MF), and inorganic compound fertilizer (ICF) treatments were significantly (p < 0.05) lower compared with carbon-based slow-release fertilizer (CSF) and organic-inorganic compound fertilizer (OCF), respectively. Meanwhile, the TP runoff losses in OCF and ICF treatments were significantly (p < 0.05) lower than U and MF, respectively. Overall, the application of ICF is a better choice to avoid N and P losses via runoff from saline-alkali paddy fields.

Optimizing fertilizer management mitigated net greenhouse gas emissions in a paddy rice-upland wheat rotation system: A ten-year in situ observation of the Yangtze River Delta, China

Optimizing the type and rate of nitrogen (N) fertilizer is an effective approach for achieving food security and minimizing environmental impacts. In this study, a ten-year in situ field experiment was conducted to evaluate the interannual responses of crop yields and greenhouse gas (GHG) emissions to the continuous application of chemical fertilizer (CF) and partial manure application (30 %, CFM) in a paddy rice-upland wheat rotation system. The results indicated that the trends of crop yields and GHG emissions were stable over ten years, and an appropriate N rate (200/150 kg N ha-1 for rice/wheat) in the rice-wheat system had greater potential for maintaining crop yields (9.25/3.32 t ha-1 for rice/wheat) and reducing their net GHG emissions by 20.8–38.7 % in contrast to the high rate (300/225 kg N ha-1 for rice/wheat). Among CF treatments, CH4 emissions had a negative correlation with the N rate, while N2O emissions were positively correlated. The CFM treatments significantly increased CH4 emissions (37.5–112.2 %) compared to the CF treatments during the rice season, but mitigated N2O emissions during both the rice (55.7–58.2 %) and wheat season (32.0–48.2 %). In a comprehensive assessment of the CH4 and N2O emissions in rice-wheat system, 81 % of the net GHG emissions was occurred in the rice season, and there was no significant difference between the CF and CFM at rate of 200/150 kg N ha-1. The study suggests that partial manure application at an optimum rate can effectively mitigate GHG emissions and be beneficial for the sustainability of rice and wheat production in a paddy rice-upland wheat rotation system.

تأثير نوع السماد الآزوتي في نمو وإنتاجية صنفين من الذرة الصفراء مزروعين في تربة كلسية

الملخص أجري البحث في محطة بحوث ستخيرس التابعة لمركز البحوث العلمية الزراعية في اللاذقية-سوريا لعام 2020، لدراسة تأثير نوعين من الاسمدة الآزوتية وهما سلفات الأمونيوم [(NH4)2SO4] ونترات البوتاسيوم [KNO3]) على معايير النمو والإنتاجية لصنفين من الذرة الصفراء (صنف دينا F1 وصنف فيحاء) المزروعين في تربة كلسية بالإضافة لمعاملة الشاهد بدون اضافة للآزوت وبمعدل ثلاث مكررات لكل معاملة، حيث صممت التجربة بنظام تصميم القطع المنشقة (Split Plots)؛ وبلغ عدد القطع التجريبية 18 قطعة. أظهرت النتائج تفوق الصنف دينا F1 (صنف أجنبي) على الصنف فيحاء (صنف محلي) من حيث ارتفاع النبات وخلال مراحل النمو المختلفة وأيضا في متوسط الانتاجية. وأن التسميد الآزوتي قد أثر في الصفات المدروسة بشكل معنوي حيث تفوقت معاملة سلفات الأمونيوم على باقي المعاملات في ارتفاع النباتات والوزن الجاف وكذلك في متوسط الإنتاجية للعرانيس الطازجة. كما بينت نتائجنا أن أعلى إنتاجية للعرانيس كانت في معاملة سلفات الأمونيوم والصنف دينا F1 وقد بلغت الإنتاجية 14.04 طن/هـ.