Levels Of Nitrogen Fertilization Research Articles

Soil Nitrogen Fertility Influences the Growth and Yield of American Elderberry but Is Less Impactful than Genotype and Environment on Other Horticultural Characteristics

A long-term horticultural experiment was conducted at two geographically distinct sites in southern Missouri in 2011–15 to study the response of American elderberry [Sambucus nigra (L.) subsp. canadensis (L.) Bolli] to various soil nitrogen (N) fertilizer levels. Three commercially available elderberry cultivars (‘Adams II’, ‘Bob Gordon’, and ‘Wyldewood’) were used. The three cultivars were each assigned to 16 of 48 four-plant plots in a completely randomized manner at each site. Four replications of four N fertilizer treatments (0, 56, 112, 169 kg⋅ha−1 N) were randomly assigned to each cultivar’s plots and applied for 4 years (2012–15). Fruit yields, plant growth, phenology, and pest incidence were determined each year. Fruit quality was assessed by analyzing basic juice characteristics as well as organic acids, carbohydrates, anthocyanins, and polyphenols from 2012–14 samples. Leaf tissue analysis determined the plants’ mineral contents in 2012–14. Most factors evaluated were significantly affected by site, year, and cultivar, whereas the effects of N fertilizer treatment were less definitive. Fruit yields and plant growth increased with increasing N levels. For example, plants fertilized with 0, 56, 112, and 169 kg⋅ha−1 N produced 123, 137, 155, and 161 fruiting cymes per plot (5.8 m2), respectively. The eriophyid mite incidence was higher on fertilized plants, but other pests were not influenced by the N treatment. Basic fruit juice characteristics (soluble solids, pH, titratable acidity, polyphenols) were not influenced by the N treatment, whereas total anthocyanins were statistically higher in unfertilized plants. Levels of organic acids and carbohydrates in juice varied statistically among N treatments, but patterns were difficult to discern. Leaf N concentrations were correlated with N fertilizer levels—2.75% N with the highest fertilizer level compared with 2.55% N in unfertilized plants. Leaf levels of most other macronutrients varied, but consistent patterns did not emerge, and none of the micronutrients was different among N treatments. Although elderberry plants responded positively to increased N fertilizer levels in terms of plant growth and fruit yield, genetics (cultivar) and environment (site, year) were more influential on most other experimental factors evaluated.

A Systematic Review on Effects of Nitrogen Fertilizer Levels on Cabbage (Brassica oleracea var. capitata L.) Production in Ethiopia.

Cabbage (Brassica oleracea var. capitata L.) holds significant agricultural and nutritional importance in Ethiopia; yet, its production faces challenges, including suboptimal nitrogen fertilizer management. The aim of this review was to review the possible effect of nitrogen fertilizer levels on the production of cabbage in Ethiopia. Nitrogen fertilization significantly influences cabbage yield and quality. Moderate to high levels of nitrogen application enhance plant growth, leaf area, head weight, and yield. However, excessive nitrogen levels can lead to adverse effects such as delayed maturity, increased susceptibility to pests and diseases, and reduced postharvest quality. In Ethiopia, small-scale farmers use different nitrogen levels for cabbage cultivation. In Ethiopia, NPSB or NPSBZN fertilizers are widely employed for the growing of various crops such as cabbage. 242 kg of NPS and 79 kg of urea are the blanket recommendation for the current production of cabbage in Ethiopia. The existing rate is not conducive for farmers. Therefore, small-scale farmers ought to utilize an optimal and cost-effective nitrogen rate to boost the cabbage yield. Furthermore, the effectiveness of nitrogen fertilization is influenced by various factors including the soil type, climate, cabbage variety, and agronomic practices. Integrated nutrient management approaches, combining nitrogen fertilizers with organic amendments or other nutrients, have shown promise in optimizing cabbage production while minimizing environmental impacts. The government ought to heed suggestions concerning soil characteristics such as the soil type, fertility, and additional factors such as the soil pH level and soil moisture contents.

Exploring Biochar with N-Fertilizer Effects on Soil CO2 Emissions and Physical-Chemical Properties as a Climate Change Mitigation Tool

Abstract The global agriculture industry is facing never before faced issues in the form of soil degradation, water scarcity, rising greenhouse gas emissions, and climate change. Among the possible remedies, applying biochar to the soil has drawn interest as a viable strategy. Although a great deal of literature has been written about the benefits and drawbacks of applying biochar initially, there is still a significant amount of research on the effects of using biochar repeatedly. This study seeks to address this gap by examining the varied effects of both the initial application (at rates of 0 t.ha−1, 10 t.ha−1, and 20 t.ha−1) and the reapplication of biochar (at rates of 0, 10, and 20 t.ha−1), especially when combined with different levels of nitrogen fertilizer (0, 108, and 162 kg.ha−1). The investigation focuses on soil properties and CO2 emissions from Haplic Luvisol in the temperate climate zone (Slovakia). The results showed that biochar generally improved soil properties, such as soil pH (KCl) (p <0.05), shifting it from acidic towards moderately acidic, and generally led to a decrease in ammonium (NH4 +) and nitrate (NO3 -) content. The second level of fertilization, combined with different biochar treatments, yielded the most efficient results in physical properties such as soil temperature, bulk density (BD), and soil water content (SWC) compared to control treatments without biochar. Biochar application contributed to the reduction of both average daily CO2 emissions and cumulative CO2 emissions during the study period (April – October) in 2022 compared to the control without biochar application.

Nitrogen fertilization modulates rice phyllosphere functional genes and pathogens through fungal communities

The phyllosphere is a vital yet often neglected habitat hosting diverse microorganisms with various functions. However, studies regarding how the composition and functions of the phyllosphere microbiome respond to agricultural practices, like nitrogen fertilization, are limited. This study investigated the effects of long-term nitrogen fertilization with different levels (CK, N90, N210, N330) on the functional genes and pathogens of the rice phyllosphere microbiome. Results showed that the relative abundance of many microbial functional genes in the rice phyllosphere was significantly affected by nitrogen fertilization, especially those involved in C fixation and denitrification genes. Different nitrogen fertilization levels have greater effects on fungal communities than bacteria communities in the rice phyllosphere, and network analysis and structural equation models further elucidate that fungal communities not only changed bacterial-fungal inter-kingdom interactions in the phyllosphere but also contributed to the variation of biogeochemical cycle potential. Besides, the moderate nitrogen fertilization level (N210) was associated with an enrichment of beneficial microbes in the phyllosphere, while also resulting in the lowest abundance of pathogenic fungi (1.14 %). In contrast, the highest abundance of pathogenic fungi (1.64 %) was observed in the highest nitrogen fertilization level (N330). This enrichment of pathogen due to high nitrogen level was also regulated by the fungal communities, as revealed through SEM analysis. Together, we demonstrated that the phyllosphere fungal communities were more sensitive to the nitrogen fertilization levels and played a crucial role in influencing phyllosphere functional profiles including element cycling potential and pathogen abundance. This study expands our knowledge regarding the role of phyllosphere fungal communities in modulating the element cycling and plant health in sustainable agriculture.

Soil tillage reduction as a climate change mitigation strategy in Mediterranean cereal‐based cropping systems

AbstractAccording to climate change projections, global temperatures would increase by 2°C by 2070, and agriculture is expected to be among the most affected sectors, particularly intensive field crops like cereals. Therefore, researchers need to investigate the most cost‐effective agricultural strategies that can prevent production losses and ensure global food security. This study aimed to identify the limiting factors of durum wheat (Triticum turgidum L. subsp. Durum (Desf.) Husn.) yield production under Mediterranean conditions. Durum wheat yield data of over 5 years (2017–2022), from a 30‐year rainfed long‐term experiment conducted in the ‘Pasquale Rosati’ experimental farm of the Polytechnic University of Marche in Agugliano, Italy (43°32’ N, 13°22′ E, 100 a.s.l.) on Calcaric Gleyic Cambisols with a silt‐clay texture, were analysed and compared with the recorded thermo‐pluviometric trend. The field trial included two soil managements (no tillage vs. conventional tillage) and three Nitrogen (N) fertilization levels (0, 90, and 180 kg N ha−1). The most important driver for durum wheat production was N fertilization. However, in the absence of N fertilization, no tillage showed a higher yield (+1.2 t ha−1) than conventional tillage due to the accumulation of organic matter in the soil. When wheat was fertilized with 90 kg N ha−1, no tillage resulted in 25% yield more than conventional tillage (+1.2 t ha−1), but this occurred only when the increase in temperatures was constant from January until harvest (this happened in 3 of 5 years of monitoring). The non‐constant increase in temperature from January to wheat harvest may hamper crop phenological development and reduce the potential yield. The highest fertilization rate (180 Kg N ha−1) resulted in the highest wheat yields regardless of soil management and thermo‐pluviometric trends (5.78 t ha−1). After N fertilization and soil management, the minimum and maximum temperature in February and the maximum temperature in April were crucial for durum wheat production under Mediterranean condition. When there is non‐constant increase in temperature from January to wheat harvest no‐tillage should be preferred over conventional tillage because wheat yields did not reduce under no tillage. Thus, agricultural policies that support the switch from conventional tillage to no‐tillage management should be promoted to enable food security in Mediterranean environments.

Field and Economic Evaluation of Barley Productivity as Affected by Seed Rates and Slow-release Nitrogen Fertilizer Levels under Rainfed Conditions

A field experiment was conducted at the north western coast of Egypt under rainfed conditions to study the effects of seed rates (70, 95 and 120 kg ha-1) and nitrogen fertilizer treatments (0, 35, 70 and 105 kg N ha-1) of Ensiabeen-40% N as slow-release fertilizer compared with 105 kg N ha-1 as Ammonium nitrate (33.5%N) on productivity of barley cultivar Giza134. This investigation was conducted during 2019/2020 and 2020/2021 winter growing seasons. The treatments were laid out in a split plot design, with three replications. Plant height, spike length, number of grins spike-1, number of spikes per m2, 1000 grain weight, biological and grain yield were recorded. In addition, total income and net return (LE)/hactare were calculated. The results indicated that mean squares due to seasons, seed rates, nitrogen levels and their interactions were significant for most studied traits. Mean performance of the studied traits as affected by seasons, seed rates and nitrogen levels showed that, the most desirable values were obtained by SR1 for spike length (6.13cm), number of grains spike-1 (48.78 grain) and 1000 grain weight (42.15g), from SR2 for Biological yield (6.02 ton ha-1) and grain yield (1.85 ton ha-1) and from SR3 for plant height (78.28cm) and number of spikes m-2 (180.11 spike). For nitrogen level effects, N4 recorded the most favorable values for all studied traits; plant height (81.48cm), spike length (6.33cm), number of grains spike-1 (49.99 grain), number of spikes m-2 (187.60 spike), Biological yield (6.88 ton ha-1), grain yield (2.12 ton ha-1) and 1000 grain weight (42.89g). Grain yield exhibited highly significant and positive correlation with each of plant height (r= 0.833**), spike length(r=0.621**), number of grains spike-1 (r=0.768**), number of spikes m-2(r=0.880**) and weight of 1000 grains (r= 0.661**). The most contributing variable in the total variation of grain yield were number of spikes m-2, number of grains spike-1 and spike length. These variables contributed by 92.9% in the grain yield variation. The results also indicated that, the highest values in the total income were 19149 and 24990 pound.hec-1 respectively, and net return were 9492 and 15498 pound.hec-1 obtained from the interaction between seed rate of 5kg ha-1 (SR2) and 105 unit of slow release fertilizer (N4) during the two growing seasons. It could recommend this treatment to maximize the total income for the farmers in such location.

Growth and Yield Responses of Green Mustard (Brassica juncea L.) by using Cow Manure and Nitrogen Levelsat Wet Season By IJISRT

Green mustard is a kind of vegetables that is easy to plant and it has nutrition for our health. The method to use or select varieties is a good technique to yield of green mustard and fertilizer also plays a key role to increase the growth of green mustard. The purpose of this research was to show the method for using cow manure with the levels of nitrogen fertilizer in responding to growth and yield of varieties of green mustard (Brassica juncea). This experiment had two factors such as three varieties of green mustard and cow manure with the three levels of nitrogen fertilizer. Factor number one was the green mustard varieties (Brassica juncea): (V1) the pretty mustard, (V2) the black mustard (coss) and (V3) the green - leaf mustard. Factor number two was the use of cow manure of 20 t/ha with three levels of nitrogen fertilizer: (F1) nitrogen fertilizer of 0 Kg/ha, (F2) nitrogen fertilizer of 15 Kg/ha and (F3) nitrogen fertilizer of 30 Kg/ha. The experiment was done by using Randomized Complete Block Design (RCBD) with 4 replications, 9 treatment combinations, which were equal to 36 small plots. It was done at Thmor Sar village, Svay Chrum commune, Svay Chrum district, Svay Rieng province, Cambodia from September to December, 2022. The results showed that the higher yield of green mustard was the treatment combination of (V3F3) and it provided 8.92 t/ha. So, it could be concluded that the better variety of green mustard was V3 (green - leaf mustard) by using F3 (fertilizer) cow manure of 20 t/ha with nitrogen fertilizer of 30 Kg/ha that it could provide a higher yield (8.92 t/ha).

Expected effects of climate change on the soil organic matter content related to contrasting agricultural management practices based on a crop model ensemble for locations in Czechia

The organic matter stored in soils is a major carbon pool with fundamental importance for the global atmospheric carbon balance. Its decomposition contributes not only to the emission of greenhouse gases into the atmosphere but also to the release of minerals that serve as nutrients for plants growing in these soils. SOC is an indicator of soil fertility, reflecting the influences of agricultural practices on this property. Using crop models, the amount of soil organic carbon (SOC) can be simulated under the assumption of different climate scenarios and different agricultural practices. The conventional agricultural practice in Czechia includes short crop rotations of mainly cereals and oil-seed rape, mineral fertilisation and removal of crop residues for technical and energy use. However, the conventional approach is often associated with soil degradation and constant depletion of soil carbon stocks. Based on the standard crop rotation method, we compared the conventional practice (CR1) to an alternative practice (CR2), in which more effort is made towards stabilising soil carbon stocks by including cover crops in the rotation, organic fertilizers and leaving crop residues in the field. We used an ensemble of crop models (APSIM, DAISY, DSSAT, HERMES, and MONICA) to assess the carbon loss from two typical agricultural soils (Chernozem and Cambisol) at three locations in Czechia under current and future climate conditions (RCP 8.5, as represented by five global climate models). The ensemble simulations revealed that using CR2 could lead to an average increase in the SOC content by 15.427 kg/ha for Chernozem and 12.624 kg/ha for Cambisol until 2080. With the use of CR1 the SOC values on average decreased by 34.462 kg/ha for Chernozem and 24.096 kg/ha for Cambisol until 2080. The 1990 value was taken as the SOC reference level. Furthermore, both the increase (CR2) and decrease (CR1) amounts SOC stabilised after 2050. As such, even at the cost of high levels of nitrogen fertilisation and the associated risk of nitrogen leaching (CR2), the additional carbon that can be stored in soils is limited. The differences due to the different climate models are negligible in the case of CR1, while in the case of CR2, the different climate scenarios (baseline vs. future) yielded different SOC equilibrium levels, with a lower level (by 4.400 kg/ha on average) under the RCP 8.5 scenario for both soils. The results showed that carbon can be sequestered by increasing organic inputs. The crop models predicted that CR2 could lead to a higher SOC content, which occurs at the cost of high manure application levels and increased risk of nitrogen leaching.

Analysis of Erect-Panicle Japonica Rice in Northern China: Yield, Quality Status, and Quality Improvement Directions.

China is the only country that extensively cultivates the indica and japonica rice varieties, with the largest japonica rice production area being in northeast China. A study of the relationship between the yield and quality of japonica rice and the effect of nitrogen fertilizer application on this relationship is important. In this paper, we aimed to assess the current yield and quality of japonica rice in northeast China. We selected erect-panicle varieties as the test materials. Field experiments were conducted using different nitrogen fertilizer levels for two consecutive years to analyze the rice varieties' yield, quality, interrelationship, and nitrogen fertilizer response. The average yield following high- and low-nitrogen treatments exceeded 10,000.00 kg/hm2, with a maximum of 12,285.63 kg/hm2. The high-yield-high-nitrogen treatment group had more panicles, a higher seed-setting rate, and a higher 1000-grain weight than the other groups. The high-yield-low-nitrogen group had a higher number of panicles and seed-setting rate than the other groups. The low-yield-high-nitrogen group had a lower number of whole grains, grain length-to-width ratio, and taste value than the other groups. The low-yield-low-nitrogen group had fewer primary branches than the other groups; excluding the primary branch-setting rate and 1000-grain weight, the values of the other panicle traits of the group were significantly higher than those of the other groups. The high-nitrogen-high-flavor group had lower panicle and spikelet numbers and higher spikelet fertility rates than the other groups. The low-nitrogen-high-flavor group had higher spikelet fertility rates and 1000-grain weight than the other groups. Compared to the other groups, the low-nitrogen-high-flavor group had a higher head rice yield, and the high-nitrogen-high-flavor group had a lower chalkiness rate. The main goal of the breeding and cultivation of high-yield and high-quality erect-panicle japonica rice in northern China is to achieve "dual high, dual low, and one high and one low" conditions, signifying a high yield with high or low nitrogen levels, low protein and amylose contents, high head rice rates, and low chalkiness. This study provides a new technique for enhancing the taste of northern erect-panicle japonica rice to promote the sustainable, high-yield, and high-quality development of japonica rice in northern China.

Effects of Intercropping and Nitrogen Application on Soil Fertility and Microbial Communities in Peanut Rhizosphere Soil

The intercropping of peanuts and sugarcane is a sustainable planting model that deserves in-depth research. For this study, two variables, i.e., intercropping status (peanut monocropping or sugarcane/peanut intercropping) and the level of nitrogen fertilization (low, medium, or high), were evaluated to analyze the effects of intercropping and nitrogen application on soil fertility and microbial communities in peanut rhizosphere soil. These analyses revealed that higher nitrogen application led to increased total nitrogen (TN), available nitrogen (AN), and soil organic matter (OM) levels in rhizosphere soil for both monocropped and intercropped peanuts, with a decrease in pH. Monocropped peanuts had higher TN, total phosphorus (TP), and total potassium (TK) levels compared to intercropped peanuts at the same nitrogen level but lower AN content and pH levels. The diversity of microbial communities in the rhizosphere soil of intercropped peanuts was significantly higher than that of monocropped peanuts under high levels of nitrogen fertilizer application. Higher levels of Gemmatimonadetes abundance were observed in intercropping rhizosphere soil, compared to that associated with peanut monocropping under low, middle, and high levels of nitrogen fertilizer application, whereas the opposite trend was observed for Chloroflexi abundance. Nitrospira abundance levels rose gradually in the monocropping treatment group, whereas the opposite trend was evident under intercropping conditions. Further analyses of nitrogen cycle-related genes demonstrated higher levels of nitrogen conversion cycle activity in intercropping peanut rhizosphere soil under low nitrogen levels, whereas nitrogen transformation cycle activity levels were higher in monocropping peanut rhizosphere soil under high levels of nitrogen amendment. It can be concluded that intercropping and nitrogen fertilizer application change the physical and chemical properties of soil, thus affecting the diversity and function of soil microbial communities in the peanut rhizosphere. These results offer a theoretical foundation for more efficient sugarcane/peanut intercropping systems.

Effects of irrigation and fertilization with biochar on the growth, yield, and water/nitrogen use of maize on the Guanzhong Plain, China

Excessive water and nitrogen inputs in agricultural production can result in resource wastage and environmental pollution. This makes it imperative to identify effective farmland management strategies to ensure sustainable agriculture development, and it remains to be explored whether biochar can be an effective solution. In this study, a 2-year (2021 and 2022) field experiment was conducted with two irrigation levels, W100 (ET) and W80 (0.8 ET), and three nitrogen fertilizer levels, NH (270 kg ha−1), NM (180 kg ha−1), and NL (90 kg ha−1), in full combination with biochar (30 t ha−1). The NM and N0 treatments without biochar at both irrigation levels were set as controls. The results of the study showed that there was no significant difference in maize yield between the high and medium N treatments. Further, maximum water productivity (WP), nitrogen agronomic efficiency (NAE), and nitrogen recovery efficiency (NRE) were obtained in NM treatments when water and nitrogen were kept consistent. Deficit irrigation was effective in reducing water consumption and increased WP by 15.54% and 11.06% in 2021 and 2022, respectively. Biochar application increased WP, nitrogen use efficiencies, and significantly increased the yield by 7.02% and 6.46% in 2021 and 2022, respectively. Therefore, the application of biochar can be an effective measure to promote crop growth and resource use. Based on the results of this experiment, an irrigation level of 0.8 ET in combination with NM and biochar application is recommended to ensure the sustainability of agricultural production.

Assessing light and quality indicators of fodder at different levels of nitrogen fertilizer based on additive intercropping of barley (Hordeum vulgare) and vetch (Vicilia ervilia) under dryland farming

The intercropping system leads to increasing radiation use efficiency and quality indicators and improving the stability in the production of fodder plants. Intercropping and reducing the use of chemical fertilizers are the most effective methods to achieve sustainable agriculture goals. To investigate light and quality indicators of fodder obtained from barley and vetch additive intercropping at different levels of nitrogen fertilizer, a split plot experiment was performed with a randomized complete block design (RCBD) and 4 replications in two experimental fields in Sisab and Shirvan, North Khorasan Province, Iran, during 2017–2018. The factor included nitrogen fertilizer at three levels (zero, 50 and 100 Kg.ha−1 (N0, N1 and N2)) and the subfactor included the combination of crops at four levels (barley pure cropping (I1), 15% vetch +100% barley (I2), 30% vetch +100% barley (I3) and 45% vetch + 100% barley (I4) additive intercropping). The results showed the highest fodder dry weight, absorbed radiation, radiation use efficiency, light extinction coefficient, ground cover percentage and leaf area index (LAI) in I3 and N2 in Sisab, and the lowest in I1 and N0 in Shirvan. Also, the highest crude protein (CP) was obtained from I4 and N2 in Shirvan, and the lowest crude protein was obtained from I1 and N0 in Sisab, which was inconsistent with neutral detergent fiber (NDF). The study results showed that increasing the percentage of vetch by 30% in intercropping and using nitrogen fertilizer led to increases in the indicators measured in the experiment.

Effect of Vermicompost and Nitrogen Fertilizer on the Growth and Production of Aloe Vera

Purpose: The effect of vermicompost and nitrogen fertilizers on the growth and production of Aloe vera were conducted using factorial based on Randomized Complete Block Design (RCBD).
 Background: Vermicompost can be used in sustainable agriculture to support growing populations by increasing water holding capacity, nutrient supply, high porosity, adequate ventilation and drainage, and production of plant hormones that have beneficial effects on seed germination.
 Methods: According to the RCBD method, treatments were included: four levels of vermicompost (V0: Control, V1: 75, V2: 150 and V3: 200 g per pot) and four levels of nitrogen fertilizer (N0: control, N1: 500, N2: 1000, and N3: 1500 mg per pot) using urea.
 Results: The results showed that application of 150 g of vermicompost and 1000 mg of nitrogen had the highest effect on growth traits, and application of 200 g of vermicompost and 1500 mg of nitrogen had the greatest effect on sucker characteristics, so that the highest number of suckers was obtained by using 200 g of vermicompost and 1000 and 1500 mg of nitrogen. However, simultaneous application of 150 g of vermicompost and 1000 mg of nitrogen had the greatest effect on plant height, number of leaves, and leaf diameter, and treatment with 200 g of vermicompost and 1500 mg of nitrogen had the greatest effect on the number of suckers, stem weight, number of leaves, sucker height, total biomass and Aloin content.
 Conclusions: Therefore, simultaneous use of vermicompost and nitrogen fertilizer in Aloe vera cultivation plays an important role in the production and enhancement of sucker and plant yield.

Moderate nitrogen application facilitates Bt cotton growth and suppresses population expansion of aphids (Aphis gossypii) by altering plant physiological characteristics.

Excessive application of nitrogen fertilizer in cotton field causes soil and water pollution as well as significant increase of aphid population. Reasonable fertilization is an important approach to improve agricultural production efficiency and reduce agriculture-derived pollutions. This study was aimed to explore the effects of nitrogen fertilizer on the Bt cotton physiological characteristics and the growth and development of A. gossypii, a sap-sucking cotton pest. Five different levels of Ca(NO3)2 (0.0 g/kg, 0.3 g/kg, 0.9 g/kg, 2.7 g/kg and 8.1 g/kg) were applied into vermiculite as nitrogen fertilizer in order to explore the effects of nitrogen fertilizer on the growth and development of Bt cotton and aphids. The results showed that the medium level of nitrogen fertilizer (0.9 g/kg) effectively facilitated the growth of Bt cotton plant and suppressed the population expansion of aphids, whereas high and extremely high nitrogen application (2.7 and 8.1 g/kg) significantly increased the population size of aphids. Both high and low nitrogen application benefited aphid growth in multiple aspects such as prolonging nymph period and adult lifespan, enhancing fecundity, and improving adult survival rate by elevating soluble sugar content in host Bt cotton plants. Cotton leaf Bt toxin content in medium nitrogen group (0.9 g/kg) was significantly higher than that in high (2.7 and 8.1 g/kg) and low (0.3 g/kg) nitrogen groups, but Bt toxin content in aphids was very low in all the nitrogen treatment groups, suggesting that medium level (0.9 g/kg) might be the optimal nitrogen fertilizer treatment level for promoting cotton seedling growth and inhibiting aphids. Overall, this study provides insight into trophic interaction among nitrogen fertilizer levels, Bt cotton, and cotton aphid, and reveals the multiple effects of nitrogen fertilizer levels on growth and development of cotton and aphids. Our findings will contribute to the optimization of the integrated management of Bt cotton and cotton aphids under nitrogen fertilization.

Influence of Nitrogen Fertilisation Level and Weather Conditions on Yield and Quantitative Profile of Anti-Nutritional Compounds in Grain of Selected Rye Cultivars

Cultivar, habitat conditions and agrotechnology have an influence on the yield and chemical composition of rye grain. The main anti-nutritional substances present in rye grain include alkylresorcinols, water-soluble pentosans and trypsin inhibitors. The aim of this study was to determine the variability in yield and the concentration of anti-nutritional compounds in the grain of selected winter rye cultivars in relation to nitrogen fertilisation levels and weather conditions. Field studies were conducted at the Experimental Station of IUNG-PIB in Osiny (Poland) in two growing seasons (2018/2019 and 2019/2020). The experiment was located on pseudo-polylic soil using the randomised sub-block method in three replications. The first factor of the experiment was the level of nitrogen fertilisation (0, 70 and 140 kg N∙ha−1) and the second was the population (Dańkowskie Skand, Piastowskie) and hybrid (KWS Vinetto, SU Performer) winter rye cultivars. The study showed that the yield of winter rye depended on the genotype and the level of nitrogen fertilisation. The hybrid cultivars yield ed 17.9% higher in relation to the population cultivars. The content of anti-nutritional compounds in rye grain depended significantly on genotype, level of nitrogen fertilisation and weather conditions. The reason for the higher synthesis of anti-nutrients in rye grain was the stressful weather conditions occurring in the 2019/2020 season. Nitrogen fertilisation influenced the content of alkylresorcinols, water-soluble pentosans and trypsin inhibitor activity in grain. The interaction of cultivar and fertilisation was also found to shape the content of the aforementioned anti-nutrients.

Sustainability analysis of irrigated and rainfed wheat production systems under varying levels of nitrogen fertilizer through coupling of emergy accounting and life cycle assessment

Most of the crop production systems have strived for improving crop productivity by increasing various resource inputs; especially water and synthetic nitrogen (N) fertilizer, without considering their environmental consequences. Yet, only few studies have evaluated the sustainability of cropping systems simultaneously using life cycle assessment (LCA) and emergy accounting (EMA) techniques. The former highlights pollutant emissions and environmental impacts, while the latter emphasizes resource consumption and system efficiency. In this three-year field study, the environmental impacts and sustainability of farming systems were estimated under rainfed and irrigated patterns at four N application rates in the Northwest China. Our result indicated that the irrigated pattern enhanced grain yield by 9%, while simultaneously increasing 8% of environmental impact and 12% of emergy input based on per hectare of wheat production. Almost similar results of environmental impact per kg basis of grain production and emergy sustainability index revealed that irrigation practice did not decrease the overall sustainability of a cropping system. Conversely, the higher N levels of 240 and 360 kg N ha−1 did not provide a proportionate yield return and were accompanied by increased environmental impacts of 20% and 69%, respectively on per kg grain production basis, when compared to an N dose of 120 kg N ha−1. Meanwhile, the gross unit emergy value revealed that the production efficiency under 120 kg N ha−1 was enhanced, in comparison with other N levels. Therefore, a moderate N dose of 120 kg N ha−1 under both irrigated and rainfed patterns is highly recommended for adoption due to its overall advantage in terms of yield returns, environmental impact and production efficiency.

CO2 elevation and N fertilizer supply modulate leaf physiology, crop growth and water use efficiency of maize in response to progressive soil drought

AbstractElevated atmospheric CO2 concentration (e[CO2]) and varied nitrogen (N) fertilization levels may mediate the different responses of C4 crops to progressive soil drought. In this study, the effects of reduced N (N1, 0.8 g pot−1) and adequate N (N2, 1.6 g pot−1) supply on leaf physiology, plant growth and water use efficiency (WUE) of maize (C4 crop) exposed to progressive soil drought grown at ambient CO2 (a[CO2], 400 ppm) and elevated CO2 (e[CO2], 800 ppm) concentration were investigated. The results indicated that compared with a[CO2], net photosynthetic rate (An) and leaf water potential (Ψl) at e[CO2] were maintained in maize leaves, while stomatal conductance (gs), transpiration rate and leaf hydraulic conductance were decreased, leading to enhanced WUE from stomatal to leaf scale. Despite An and Ψl of e[CO2] plants were more sensitive to progressive soil drought under both N fertilization levels, e[CO2] would increase leaf ABA concentration ([ABA]leaf) but decline the gs response to [ABA]leaf under N1 supply. e[CO2] coupled with N1 fertilization was conducive to enlarging leaf area, promoting specific leaf area, root and total dry mass, whereas reduced stomatal aperture and plant water use under progressive drought stress, contributing to an improvement in plant WUE, implying a better modulation of maize leaf stomata and water status under reduced N supply combined with e[CO2] responding to progressive soil drought. These findings in the current study would provide valuable advice for N management on maize (C4) crop efficient water use in a drier and CO2‐enriched environment.

Response of tomato (Solanum lycopersicum) to varying levels of irrigation and nitrogen under trickle fertigation

An experiment was conducted during 2022 and 2023 at Lovely Professional University, Jalandhar, Punjab to study the response of tomato (Solanum lycopersicum L.) to 3 irrigation levels [I1, 70%; I2, 85% and I3, 100% of IWR] and 3 nitrogen fertilization levels [N1, 70%; N2, 85% and N3, 100% of RDN] in split plot design. On individual effect basis, the fruit yield first increased with the increase in amount of applied irrigation water in I2 (95.6 t/ha) and then decreased in I3 (93.5 t/ha). Irrigation water use efficiency (IWUE) was the highest in I2 (3.73 t/ha-cm). Plant growth, tomato yield and IWUE were significantly higher in N2 than that were found in N1 and N3. Nitrogen use efficiency (NUE) decreased with increasing nitrogen levels (N2 and N3) but it increased with increasing amount of water applied (I3). The treatments having deficit irrigation level as I1 and I2, significantly enhanced the lycopene content (27 to 33 µg/g) and reduced the nitrate content (74 to 95 mg/kg) in the fruit over full irrigation level I3. Nitrate content was highest in N3 (100 mg/kg). Among all the combination of irrigation and nitrogen fertilization levels the interaction of I2N2 (85% of IWR and RDN) was found the best to grow the drip-irrigated tomato crop. This combination gave optimum plant growth (87.5 cm), fruit yield (100 t/ha), IWUE (3.93 t/ha-cm), NUE (0.79 t/kg) and good quality fruit. The findings can be utilized for irrigation planning and nitrogen management in tomato cultivation and to conserve available fresh water resources in water scare regions of Punjab. In order to promote trickle fertigation at village level, the awareness programs for farmers could be conducted.

Effect of nitrogen fertilization levels and plant density on dry weight, yield components and bulb quality of onion plant

A field experiment was carried out during the two successive winter seasons of 2020/2021 and 2021/2022 to study the effect of mineral nitrogen levels and plant density on dry weight, yield and its components, as well as bulb quality of onions (cv. ‘Ahmar Tanawy’). This experiment included 12 treatments, which were combinations between four levels of mineral nitrogen (0, 192, 240 and 288 kg N/ha) and three plant densities (4, 5 and 6 rows/ridge equal 33.33, 41.67 and 50 plants/m2, respectively). These treatments were arranged in a split-plot design with three replications. Nitrogen levels were randomly arranged in the main plots, and plant densities were randomly distributed in the subplots. Nitrogen application at 192,244 and 288 kg N/ha led to increase dry weight/plant compared to control (zero N) and 288 kg N/ha gave the highest values of dry weight of leaves, dry weight of bulbs, and total dry weight per plant at 100 days in both seasons. The increases in total dry weight per plant were about 4.84 and 4.80 g per plant for 192 kg N/ha, 4.76 and 3.87 g per plant for 244 kg N/ha, and 6.86 and 5.74 g per plant for 288 kg N/ha over the control at 100 days in the 1st and 2nd seasons, respectively. The interaction between N at 288 kg/ha and low plant density (4 rows/ridge) gave the highest values of dry weight of leaves, bulb, and total dry weight/plant and increased yield of grade 1, exportable yield, average bulb weight, as well as nitrate and sulphur contents in bulbs, whereas the interaction between N at 244 kg/ha and high plant density (6 rows/ridge) increased grades 2, 3, and 4, marketable yield, and total yield/ha.

Combined Application of Nitrogen and Phosphorus Promotes the Growth and Nutrient Accumulations of Cinnamomum camphora Container Seedlings

Combining the application of nitrogen and phosphorus is widely recognized as an effective measure to promote seedling growth. The purpose of this study was to investigate the effects of the combined application of nitrogen and phosphorus on the growth and nutrient status of C. camphora container seedlings. Exponential fertilization was applied to a range of fertilizers, including single nitrogen fertilizer, single phosphorus fertilizer, and combinations of nitrogen and phosphorus to C. camphora. Eight distinct fertilization levels of treatment (CK, N1, N2, N3, P, N1P, N2P, and N3P) were established. The height and ground diameter of the seedlings were determined periodically in each treatment group. Biomass, root system (including root length, root surface area, and root volume), and nutrient accumulation (content of soluble sugars, soluble proteins, and starch in the root system, stems, and leaves) were determined for each treatment group of seedlings. The N3P treatment (N: 9000 mg∙plant−1 + P: 6000 mg∙plant−1) had the most significant effect on the height and ground diameter of C. camphora container seedlings, while the N3 treatment (N: 9000 mg∙plant−1) proved to be the most beneficial for biomass accumulation among the eight different fertilizer levels. In addition, a single P fertilizer (P: 6000 mg∙plant−1) emerged as the most effective fertilizer for enhancing root morphology (root length, root surface area, root volume, and root average diameter) and accumulating nutrient composition (soluble sugar, soluble protein, and starch). Furthermore, it was discovered that a high level of nitrogen fertilization hindered the accumulation of nutrient composition in C. camphora container seedlings. Our comprehensive analysis revealed that nitrogen fertilizer promoted the morphological growth of C. camphora container seedlings, while phosphorus fertilizer proved to be the most beneficial for root growth and nutrient composition accumulation. Additionally, it was emphasized that controlling the quantity of nitrogen fertilizer is also a crucial measure.