Effect Of Nitrogen Fertilizer Rates Research Articles

Effects of nitrogen fertilization rate and seeding density on the forage yield and quality of autumn‐sown triticale in an alpine grazing area of the Qinghai‐Tibetan Plateau, China

Abstract‘Gannong No. 2’ triticale (×Triticosecale Wittmack) is a cold‐resistant annual forage crop variety, which can be planted as artificial pasture to solve the problem of forage shortage in the Gannan alpine grazing area of the Qinghai‐Tibetan Plateau. However, the optimal nitrogen fertilization rate and seeding density for obtaining high yield and quality forage are still unknown. In this study, the effects of nitrogen fertilization rate and seeding density on the forage yield and quality of autumn‐sown ‘Gannong No. 2’ triticale were studied. We used a split‐plot design, with five nitrogen fertilization rates assigned to the main plots, namely 0 (A1), 120 (A2), 240 (A3), 360 (A4), and 480 kg N ha−1 (A5), and five seeding densities assigned to subplots: 506 × 104 (B1), 675 × 104 (B2), 843 × 104 (B3), 1011 × 104 (B4), and 1180 × 104 seeds ha−1 (B5). Significant differences in lodging rate, tiller number, hay yield, crude protein content, neutral detergent fibre, and relative feed value were observed at different fertilization levels. Significant differences were found in lodging rate, plant height, tiller number, hay yield, contents of neutral detergent fibre and acid detergent fibre, dry matter digestibility, and relative feed value among the seeding density treatments. The interaction of nitrogen fertilization rate and seeding density significantly affected forage yield and quality, with the A3B3 treatment having the highest comprehensive evaluation value. In alpine grazing areas of the Qinghai‐Tibetan Plateau, 240 kg N ha−1 and 843 × 104 seeds ha−1 should therefore be used for autumn‐sown triticale.

Effects of Nitrogen Fertilizer Rates on Yield and Yield Components of Maize (Zea mays L.)

Maize is one of the most important cereal crops in the world. To investigate the effects of nitrogen fertilizer rates on growth and yield of maize and to determine the suitable nitrogen fertilizer rate, an experiment was conducted by using Randomized complete block design (RCBD) with four replications at Shwe Baho village, Zayarthiri Township, Nay Pyi Taw in post monsoon season and monsoon season. The treatments were T1 (no nitrogen application), T2 (90 kg N ha-1), T3 (120 kg N ha-1), T4 (150 kg N ha-1) and T5 (180 kg N ha-1) treatments. The tested maize variety was pacific-789 hybrid. According to the results, application of nitrogen gave the significant effect on grain yield and yield components of maize in both seasons. The superior maize yield was observed in all nitrogen treatments compared to control. The use of the highest nitrogen fertilizer rate (180 kg N ha-¹) in T5 gave the significant highest grain yield (7696.6 kg ha-¹) in post monsoon season and (8764.5 kg ha-¹) in monsoon season, respectively. In both seasons, the grain yield in T5 treatment was significantly increased about 62% over T1 treatment. Therefore, the application of nitrogen with the rate of T5 (180 kg ha-1) might be the appropriate rate to maximize the maize production. Considering the increased grain yield of the hybrid maize, nitrogen rate of T5 (180 kg ha-1) could be achieved in this study area.

Effect of Nitrogen Fertilizer Rates on Yield and Yield Related Traits of Durum Wheat (Triticum turgidum L.) Varieties

Low productivity and poor quality of the durum wheat compels Ethiopian pasta industries to import the required raw material; Thus, proper type and amount of nitrogen fertilizer application is the major factor that affects yield and quality components of durum wheat. Hence, field experiment was carried out on farmers’ training center field to determine the effect of nitrogen fertilizerrates in combination with durum wheat varieties on growth, yield and quality components of durum wheat. Factorial combinations of three durum varieties (Mangudo, Ude and Utuba) with six levels of nitrogen (0, 23, 46, 69, 92 and115 kgha-1) were laid out in a randomized complete block design in three replications. The analysis of variance indicated that the interaction effect of nitrogen fertilizer and variety significantly (p< 0.05) influenced 90% days to maturity and spike length. The highest days to 90% maturity (128 days) was recorded from Utuba variety at 115kg N ha-1 application. The longest spike length was recorded from Ude variety at 92 kg N ha- 1 application. However, seed per spike, plant height, productive tiller, grain yield and grain protein content were significantly (p<0.01) influenced by the main effect of nitrogen rates. The highest plant height (85.82cm), productive tiller (7.56), grain yield (4862 kg ha-1), and grain protein content (15.88%) were recorded at the highest N rate (92 kg N ha-1) applied; but, a maximum seed per spike (51.89) was obtained at the rate of 69 N kg ha-1 applied. The analysis of variance also showed that the difference of varieties significantly (p<0.01) influenced the plant height, thousand kernel weight, grain yield, and protein content with highest result obtained from Ude except highest protein content obtained from Utuba. The economic analysis revealed that for a treatment to be considered worthwhile to farmers, application of 92 kg N ha-1to all varieties gave better yields as compared to other N treatments. However, Ude variety is a promising variety for better productivity with profitable economic benefit to the crop at 92 kg N ha-1 application in the study area. However, since the study was done once in single place it is recommended to replicate it spatially and seasonally to have a concrete recommendation on the wheat varieties and nitrogen rates.

Climate and breeding determined below-ground biomass allocation strategy in wheat

Farmland covers about 12% of the ice-free terrestrial surface, and crop below-ground biomass allocation plays a pivotal role in the sequestration of atmospheric carbon. Nevertheless, our understanding of the integrated response of crop belowground biomass allocation strategy to concomitant variation in key environmental factors related to water and nutrient availability remains limited. Furthermore, it is imperative to conduct further analysis to elucidate the influence of breeding efforts geared toward improving crop yield on the below-ground biomass allocation strategy. Here we compiled a global wheat root mass fraction (RMF) database with 221 observations from 39 studies to analyze the integrated response of RMF to climate, soil properties and filed managements, and the relationship of RMF and yield. We identified an aridity index (AI) threshold of 0.44 for wheat below-ground biomass allocation strategy, based on the effect of long-term climate on plow-layer soil organic carbon and field water capacity (FWC). The negative effect of nitrogen fertilizer rate on RMF along the AI gradient did not significantly change but the main mechanism shifted from indirect to direct effects. For AI < 0.44, the response of RMF to change of water availability was relatively conservative with the insignificant effects of FWC on RMF. However, RMF was highly sensitive to precipitation distribution during the growth stage because RMF decreased as the ratio of precipitation during the reproductive stage to the growth stage increased. We did not observe a significant correlation between RMF and yield within the main range of RMF so a large amount of intraspecific variation in belowground biomass allocation strategies had not been filtered out by breeding. For AI ≥ 0.44, RMF was highly sensitive to water resource availability as RMF significantly decreased with an increase in FWC. Yield decreased significantly with increasing RMF within the main range of RMF, resulting in highly consistent intraspecific belowground biomass allocation strategies under the pressure of breeding. The results suggested long-term climate condition and breeding played critical filters in wheat below-ground biomass allocation strategy and provided a more accurate prediction of RMF for global carbon cycle models and crop growth models.

Optimizing nitrogen fertilizer application for achieving high yield with low environmental risks in apple orchard

The great challenges of food security, climate change and environmental degradation resulting from unreasonable nitrogen fertilizer (NF) inputs necessitate the optimization of fertilizer application to ensure fruit production and environmental sustainability. However, there is a lack of systematic analysis on the effects of NF inputs on apple yield and reactive nitrogen losses (N2O emission, NH3 volatilization, and nitrate leaching) at the global scale. Therefore, we used a meta-analysis of 159 observations from 31 published studies to evaluate the response of apple yield and reactive nitrogen losses to NF. We aim to identify suitable NF rates, environmental conditions, and planting factors that improve apple yield while minimizing reactive nitrogen losses. Our results showed that NF significantly increased apple yield, N2O emission, NH3 volatilization, and nitrate leaching by 17.1%, 255.7%, 236.4%, and 68.7% compared with no nitrogen fertilizer (NNF), respectively. The effects of NF rates and environmental factors on the response of N2O emission, NH3 volatilization, and nitrate leaching to NF were prior to those of planting factors, but the result of apple yield was the opposite. Apple production under NF in regions with MAT (mean annual air temperature) ≥ 10 °C and MAP (mean annual precipitation) < 600 mm declined the risk of reactive nitrogen losses and significantly increased apple yield by 24.4%−28%. NF application was more beneficial in soil with pH ≥ 7 and SOM < 15 g kg−1 for apple production. We found that the suitable NF rate was 250–450 kg ha−1, which can increase apple yield by 0.8%−21.3% while significantly reducing reactive nitrogen losses compared with lower NF rate (< 250 kg ha−1) and higher NF rate (> 450 kg ha−1). Our findings provide guidance for optimizing NF management in apple orchard to achieve high crop yields, reduce emissions, and mitigate pollution.

Assessing the performance of wheat (Triticum aestivum L.) crop by managing irrigation and nitrogen fertilizer under a semi-arid environment

Abstract Understanding the linkage between crop yields, irrigation frequencies, and fertilizer rates is crucial in region-specific agriculture practices. The present study was conducted to assess the effect of nitrogen fertilizer rates and irrigation frequency on wheat crop growth and yield in the semi-arid region of Rajasthan, India. The experiment was laid out in a randomized complete block design with 12 treatments with 4 replicas, combining 4 nitrogen fertilizers quantities (0%, 50%, 100%, and 125% of recommended dose) with 3 irrigation intervals (15, 21, and 25 days after sowing) were used for three consecutive years (2014-15, 2015-16 and 2016-17). Crop responses were recorded for different growth stages. One-way analysis of variance and Fisher's least significant difference tests were applied to determine significant changes in yield. The results showed that the high irrigation frequency and high fertilizer application significantly increased crop growth and yields. Yields observed in the first year of the experiment were higher than those in the second and third years in most treatments. The results showed that water and fertilizer are the key factors that can affect wheat yield in the semi- arid region of Rajasthan and should be managed according to soil and irrigation availability.

Effects of nitrogen fertilization rate and environment on the composition of alkylresorcinols in three elite winter wheat cultivars

We received a letter from Editorial Manager saying that “No abstract is required for Short Communication”. But we must have a file here, otherwise we cannot submit the revision.

Study the Effect of Nitrogen Fertilization Rates on Grain Yield and Some Physiological Characteristics of Wheat Varieties

One of the most important strategies for enhancing wheat grain productivity and physiological processes is the application of appropriate nitrogen (N) and the choice of a suitable variety in an adequate environment. The study goals were to assess the impact of various N application rates on the grain yield and some physiological traits of four wheat cultivars under two growing years as well as determine the relationship between these traits across the experimental factors. Four Egyptian bread wheat varieties (Sakha 93, Gemmiza 12, Sids 12, and Sakha 94) and four nitrogen rates including control (N0), 75 kg N fad-1 (N1), 100 kg N fad-1 (N2), and 125 kg N fad-1 (N3) were evaluated in two experimental fields during the 2020/2021 and 2021/2022 growing years at Sakha, Kafr El-Sheikh Governorate, Egypt. Grain yield (kg ha-1), relative water content (RWC) proline content, malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT), and ascorbate peroxidase (APX) activities were the traits under study. The grain yield and the majority of the physiological parameters assessed were significantly influenced by the years, nitrogen treatments, and varieties as well as their first and second-order interactions (p ≤0.05 or 0.01), according to Three-way ANOVA. Grain yield increased with N treatments increased, and N3 treatment was higher than N0, N1 and N3 treatments with values of 31.1%, 22.9%, and 10.6%, respectively. With increased N application there is a tendency for MDA content and SOD activity to decrease and then increase, while RWC, proline content, CAT, and ABX activities to increase and then decrease. The highest values were recorded for grain yield, proline content and CAT activity by Sakha 94 variety and for MDA content, SOD, CAT and ABX activities by Sids 12 variety. According to the interactions among experimental factors, the highest wheat yield and the majority of physiological measures were observed by Sakha 94 variety with N3 rate under the second growing year. The Sakha 94 variety shows a positive correlation with grain production and the majority of physiological parameters under applying N3 treatment during the second growing year based on all variables examined by principal component analysis. Finally, our results recommended using the Sakha 94 variety with 125 kg N fad-1 to increase and improve wheat productivity.

Yield of winter barley with different systems of mineral fertilizer and use of urease inhibitor

The use of urease inhibitors with nitrogen fertilizers is gaining relevance. There was a need to substantiate the expediency of combining these technology elements when growing winter barley. We conducted field experiments at the Lviv National Environmental University in the Banded Forest of the Western Forest Steppe conditions in 2020–2022. Our research goal is to describe the interaction of mineral fertilizers with the N-LokTM brand inhibitor, which restrains the formation of nitrates but improves the agrochemical parameters of the soil. This had a positive effect on the yield of winter barley. The soil is a dark gray forest gilded light loam with low humus. We used traditional methods of field research and standardized methods of laboratory analyses. The nitrogen fertilization system N97(NH4NO3) during vegetation restoration + N-LokTM (before sowing or during vegetation restoration) on the background of N23P60K60 ensured the initial content of easily hydrolyzable nitrogen in the arable layer of 132–136 mg/kg of soil. Applying N97(NH4NO3) + N-LokTM to winter barley during the restoration of vegetation on the background of N23P60K60 under plowing provided the highest yield in the experiment of 7.69 t/ha on average for 2020–2022. The average grain increase relative to the N97(NH4NO3) control (vegetation restoration) on the N23P60K60 background was 1.08 t/ha. On the other hand, applying N97(NH4NO3) during the restoration of vegetation + N-LokTM in autumn before sowing on the same background contributed to a more significant yield increase – by 1.26 t/ha only in 2021. The absence of a phosphorus-potassium background in the winter barley fertilization system reduced the crop yield by 0.11–0.44 t/ha. The significant importance of mineral fertilizers for obtaining high grain harvests, especially in less good years, is proven by the established high correlation coefficients of the parameters of available compounds of nitrogen, phosphorus, and potassium at the start of the growing season with the harvest in 2020–2021. The regression 3D model of winter barley grain yield under the influence of the synergistic effect of nitrogen fertilization rates and the resulting enrichment of the soil with easily hydrolyzable nitrogen illustrates the importance of fertilizers for increasing the fertility of the dark-gray podzolized light loam soil in Pasmovy Pobuzhzhia of the Western Forest Steppe.

Effects of Shallow Groundwater Depth and Nitrogen Application Level on Soil Water and Nitrate Content, Growth and Yield of Winter Wheat

The large amount of nitrogen application on the North China Plain has caused a serious negative impact on the sustainable development of regional agriculture and ecological environmental protection. Our aim was to explore the effects of nitrogen fertilization rate and groundwater depth on growth attributes, soil-water and soil-fertilizer contents, and the winter wheat yield. Experiments were carried out in micro-lysimeters at groundwater depths of 60, 90, 120, and 150 cm on the basis of 0, 150, 240, and 300 kg/ha nitrogen fertilization rates in the growth season for winter wheat. Results showed that plant height, leaf area index, soil plant analysis development, and yield without nitrogen application increased significantly with increases in groundwater depth. The optimal groundwater depths for growth attributes and yield were 60–120 cm and tended to be shallower with added nitrogen application. Soil moisture was lowered significantly with groundwater depth, adding a nitrogen application reduced soil moisture, and excessive nitrogen input intensified soil drought. Nitrate-N accumulation at the 120–150 cm depths was significantly higher than that at the 60–90 cm depths, and a 300 kg/ha (traditional nitrogen application rate) treatment was 6.7 times greater than that of 150 kg/ha treatment and increased by 74% more than that of the 240 kg/ha treatment at 60–150 cm depth. Compared with the yield of the 300 kg/ha rate, the yield of the 240 kg/ha rate had no significant difference, but the yield increased by 3.90% and 11.09% at the 120 cm and 150 cm depths. The growth attributes and yield of winter wheat were better, and the soil nitrate-N content was lower, when the nitrogen application rate was 240 kg/ha. Therefore, it can be concluded that nitrogen application can be reduced by 20% on the North China Plain.

Evaluating the effect of nitrogen fertilizer rate and source on the performance of open‐pollinated rye (Secale cereale L.) cultivars in contrasting European environments

AbstractRye (Secale cereale L.) is a minor cereal with potential to support sustainable farming practices. This study evaluated the performance of four old and modern European open‐pollinated winter rye cultivars grown with different nitrogen (N) sources (cattle slurry, farmyard manure, biogas digestate, mineral N) at two rates of N 50 and 100 kg ha−1 in the United Kingdom and Estonia, in the 2014–2015 and 2015–2016 growing seasons. Grain yield in Estonia was higher than the United Kingdom (6.2 vs. 4.8 t ha−1), which was attributed to a higher ear density (409.4 vs. 249.7 ears m−2) and grain number per ear (50.2 vs. 43.2), although 1,000‐grain weight was higher in the United Kingdom. There were clear differences between sites in the response to N source with significant N source × year interactions. Biogas digestate and mineral N produced higher grain yield than farmyard manure and cattle slurry in the United Kingdom, whereas in Estonia cattle slurry had a lower grain yield than the other N sources. Foliar diseases were absent in Estonia and in the United Kingdom, and N source only affected powdery mildew and leaf blotch on Leaf 2. The response of grain quality to N source and variety was consistent across both sites. The modern variety Elias had the highest Hagberg falling number and specific weight but the lowest protein content, whereas the variety Schlägler had the highest protein content but lowest specific weight. The benefits of selecting cultivars for specific environments are shown by the interactions between genotype and environment.

Effects of nitrogen fertilizer rates on growth and yield of maize in Makurdi-Nigeria

This experiment was conducted at the Agronomy Teaching and Research Farm of Joseph Sarwuan Tarka University, Makurdi in the 2021 rain-fed cropping season to determine the effects of nitrogen fertilizer rates on the growth and yield of maize in Makurdi, Benue State. A total of five treatments (0, 40, 80,120, 160 kg Nha-1) in the form of urea were used. These treatments were laid out in a Randomized Complete Block Design (RCBD) and replicated three times. In addition to the treatments, basal applications of Phosphorus and potassium in the form of SSP and MOP were applied at recommended rates. Maize seeds were planted and the crop grown to maturity with all cultural practices carried out as at when necessary. Data were collected on growth and yield parameters of maize and the data were subjected to the analysis of variance (ANOVA) using GENSTAT 17th Edition, while significant differences in means were separated using Least Significant Difference (LSD). The results

Effect of nitrogen fertilizer rates and splitting nitrogen on yield and yield components of Egyptian cotton cultivar Giza 90 under surface and drip irrigation systems in newly reclaimed lands

Effect of nitrogen fertilizer rates and splitting nitrogen on yield and yield components of Egyptian cotton cultivar Giza 90 under surface and drip irrigation systems in newly reclaimed lands

The effect of nitrogen fertilization rate on growth and physiological parameters of three purslane genotypes grown in a soilless cultivation system

ISHS III International Symposium on Soilless Culture and Hydroponics: Innovation and Advanced Technology for Circular Horticulture The effect of nitrogen fertilization rate on growth and physiological parameters of three purslane genotypes grown in a soilless cultivation system

Effects of nitrogen fertilizer rates on the growth and nutrient utilization of calla lily intercropped with rubber trees

Rubber tree (Heveabrasiliensis Müll. Arg.)–calla lily (Alocasiamacrorrhizos L.) intercropping, practiced in Hainan, China, is a new and promising intercropping system suitable for implementation in shaded mature rubber plantations of which the main product is industrial starch. Nutrient competition between rubber trees and calla lilies was significant in this intercropping system, with rubber trees holding a competitive advantage. In addition, nitrogen (N) fertilizer is commonly used in excess in China. Therefore, adequate N supply is the basis of rubber tree–calla lily intercropping systems that reduces inter-species N competition and ensures efficient intercropping. In this study, experiments with monocropping and intercropping systems under five different N application concentrations (0, 100, 200, 300, and 400 kg ha−1) were conducted to assess how the interaction between intercropping and N fertilizer application rates affected the growth, development, distribution of biomass, and nutrient uptake and utilization in calla lilies, using the root barrier method. The results showed that only when the N fertilizer rates were < 200 kg ha−1, intercropping significantly inhibited calla lily growth and development, but significantly increased the number and length of calla lily roots, and allocated more dry matter to the roots. however, intercropping promoted calla lily growth and development at a N fertilizer application rate of 400 kg ha−1. Intercropping increased the phosphorus (P) concentration and decreased the N and potassium (K) concentrations, and lower N fertilizer rates resulted in larger increases in the P concentration. Intercropping decreased N utilization efficiency in calla lilies, whereas adequate N fertilizer increased N utilization efficiency. These results indicated that calla lilies adapted to the intercropping and low N fertilizer rates condition by balancing growth, changing root morphology, and reserving nutrients in roots, and shows that scientific and rational fertilization application rates can eliminate the negative effects caused by intercropping due to nutrient competition. For the long-term success of intercropping calla lily in mature rubber plantations, N fertilizer must be applied to mitigate the adverse effects of interspecific competition. Based on the growth and N utilization efficiency of calla lilies in relation to N input costs, the optimal N fertilizer rate in rubber tree–calla lily intercropping systems is 200 kg ha−1.

Effects of Growing Substrate and Nitrogen Fertilization on the Chemical Composition and Bioactive Properties of Centaurea raphanina ssp. mixta (DC.) Runemark

The Mediterranean basin is abundant in wild edible species with numerous health beneficial effects due to the presence of various bioactive phytochemicals. In the present work, the effect of nitrogen fertilization rates (0 ppm, (N0), 200 ppm (N1), 400 ppm (N2), and 600 ppm (N3) of total N) and growth substrate composition (soil or peat/perlite (2/1; v/v)) on the chemical composition and bioactive properties of Centaurea raphanina ssp. mixta plants was evaluated. The results of the study showed that both the tested factors affected nutritional value of the edible leaves, with the soil × N1 treatment being the most beneficial for fat, protein, and carbohydrate content and energetic value. On the other hand, the peat/perlite-grown plants that received 200 ppm of N had the highest content in α-, γ-, and total tocopherols, while the control treatment of soil-grown plants was the richest in individual and total sugars. Oxalic, citric, and total organic acids were the highest in the N2 × soil treatment, while malic acid was the highest in control treatment of the same substrate. The main fatty acids were palmitic, α-linolenic, and linoleic acids, with the highest contents being observed in the N0 × soil, N3 × soil, and N3 × peat/perlite treatments, respectively. The major phenolic compounds were pinocembrim neohesperidoside and pinocembrim acetyl neohesperidoside isomer II, with the highest content being observed in the N1 × soil treatment. The highest antihemolytic activity was observed in the N3 × peat/perlite treatment, while the most effective treatments against lipid peroxidation were N0 (in both soil and peat/perlite combinations) and N1 × peat/perlite. Lastly, all the tested extracts (except for N1 × soil) showed promising cytotoxic effects against HeLa (cervical carcinoma), HepG2 (hepatocellular carcinoma), MCF-7 (breast carcinoma), and NCI-H460 (non-small-cell lung cancer), while all the tested extracts exhibited better antifungal activities (lower minimal inhibition concentration (MIC) values) against Trichoderma viride than the positive controls. Overall, the present results suggest that the application of cost-effective practices such as the nitrogen application and the selection of growth substrate may regulate the chemical composition and the bioactive properties of C. raphanina ssp. mixta species and increase its added value under commercial cultivation conditions.

Effect of nitrogen fertilizer rates on growth and oil yield of Java lemongrass (Cymbopogon winterianus Jawitt) in Thu Duc, Ho Chi Minh City

Java lemongrass is commonly cultivated in Vietnam for the use in industries and traditional medicine. Currently, the application of fertilizer, especially nitrogen fertilizer, is one of the most traditional farm practices to increase production yield. A single factorial experiment was carried out in a completely randomized design, three replications to determine the suitability of nitrogen fertilizer rates on growth, leaf and oil yields of Java lemongrass. Six treatments were used in this experiment including 90, 120, 150, 180, 210, 240 kg N/ha and applying 90 kg N/ha as control. Fertilizer base for treatments (for 1 ha) included 20 tons of cow dung compost, 60 kg P2O5 and 60 kg K2O. The application of 120 kg N/ha significantly improved the growth of Java lemongrass as plant height (97.0 cm/plant), average number of leaves (197.1 leaves/plant), average weight of leaves per plant (198.7 g/plant), fully leaf yield (9.4 tons/ha/2 harvest times), essential oil content (1.0% FW) and economic oil yield (97.8 kg/ha/2 harvests).

Fodder Beet (Beta Vulgaris Var Crassa) Yield and Quality Attributrs As Affected By Nitrogen Fertilization and Foliar Boron Application

A field experiment was conducted during two seasons 2018/2019 and 2019/2020 at Homs Agriculture Research Center, General Commission for Scientific Agriculture Researches (GCSAR), Syria, to study the effect of nitrogen fertilization rates and foliar application of boron on root yield and quality and dry matter yield of fodder beet. Results showed that the effect of nitrogen fertilization was significant (p≤0.001) for all studied traits except brix%. The effects were significant positive on root, shoot and biological yields, sucrose percentage, root, shoot and total dry matter yields. On the other hand the effect of boron spraying was presented for each season separately, because the differences of boron treatments were significant for all parameters except brix% at each season, and HI at the two seasons, while the differences of years were significant for all parameters except for HI. the highest yield and yield components were achieved by adding 300 kg N/ha with the addition of boron under Homs governorate conditions.

Effect of Nitrogen Fertilizer Rates and Intra-row Spacing on Yield and Yield Components of ‘Improved Huruta‘ Shallot Variety (Allium cepa var.ascalonicum) at Haramaya, Eastern Ethiopia

Agronomic practices for the newly released shallot variety have not been conducted in Eastern Ethiopia. To assess the effect of nitrogen fertilizer rates and intra-row spacing, a field experiment was conducted in 2017 which consisted of seven rates of nitrogen (0, 25, 50, 75,100,125 and 150 kg N ha-1) and three intra-row spacing (7.5, 10 and 12.5 cm) in factorial combination and it was laid out in a RCBD with three replications. Results of the analysis revealed that all bulb yield and yield components of the variety were highly significantly influenced by the main effects of nitrogen fertilizer and intra-row spacing. Moreover, the interaction of nitrogen fertilizer and intra-row spacing significantly influenced days to maturity, plant height, and average bulb weight and bulb dry matter. The application of 125 kg N ha-1gave high total and marketable bulb yield advantage of 32.45% (13.89 t ha-1) and 40.8% (15.47 t ha-1), respectively over the control. Plants spaced at 7.5 cm had total and marketable bulb yield advantage of 35.94% (14.54 t ha-1) and 32.83% (12.42 t ha-1), respectively over plants spaced at 12.5 cm. Therefore, intra-row spacing of 7.5 cm with the application of 125 kg N ha-1 is used for optimum yield in the study area although further research should be needed to come up with conclusive recommendation.

Effect of Different Rates of Nitrogen Fertilization on Crop Yield, Soil Properties and Leaf Physiological Attributes in Banana Under Subtropical Regions of China.

Excessive nitrogen (N) application is widespread in Southern China. The effects of N fertilization on soil properties and crop physiology are poorly understood in tropical red loam soil. We conducted a field experiment to evaluate the effect of nitrogen fertilization rates on physiological attributes (chlorophyll, plant metabolic enzymes, soluble matters) on banana leaves, soil properties (soil enzymes, soil organic matter (SOM), soil available nutrients) as well as banana crop yield in a subtropical region of southern China. The N rates tested were 0 (N0), 145 (N145), 248 (N248), 352 (N352), 414 (NFT), and 455 (N455) g N per plant. The correlations among soil factors, leaf physiological factors and crop yield were evaluated. The results indiated that the high rates of N fertilization (NFT and N455) significantly decreased soil available potassium (K) content, available phosphorus (P) content, glutamine synthetase (GS) activity, and soluble protein and sugar contents compared with lower N rates. The N352 treatment had the highest crop yields compared with higher N rates treatments, followed by the N455 treatment. However, there were no significant differences in crop yields among N fertilization treatments. Factor analysis showed that the N352 treatment had the highest integrated score for soil and leaf physiological factors among all treatments. Moreover, the N352 treatment was the most effective in improving carbon and nitrogen metabolism in banana. Crop yield was significantly and positively linearly correlated with the integrated score (r = 0.823, p < 0.05). Path analysis revealed that invertase, SOM and sucrose synthase (SS) had a strong positive effect on banana yield. Canonical correspondence analysis (CCA) suggested that available K, invertase, acid phosphatase and available P were the most important factors impacting leaf physiological attributes. Cluster analysis demonstrated distinct differences in N application treatment related to variations in soil and leaf factors. This study suggested that excessive N fertilization had a negative effect on soil fertility, crop physiology and yield. The lower N rates were more effective in improving crop yield than higher rates of N fertilization. The N rate of 352 g N per plant (N352) was recommended to reduce excess N input while maintaining the higher yield for local farmers’ banana planting.