Doses Of Nitrogen Fertilizer Research Articles

Effect of Light Intensities and Nitrogen Fertilizer Dosages on Growth, Phenolics, and Flavonoid Production of Adenostemma lavenia

Adenostemma lavenia (Asteraceae) is a medicinal plant considered a weed, consisted a lot of secondary metabolites, including phenolic and flavonoid. This species has been widely distributed in various countries but has yet to be widely cultivated. Thus, this study aimed to determine the highest plant growth, phenolic, and flavonoid production from A. lavenia cultivated under different shade of nitrogen fertilizers. The experiment used a nested design consisting of 2 factors. The first factor was shade with different intensities (0, 25, 50, and 75%) and the second was nitrogen fertilizer with different doses (0, 45, and 90 kg/ha). The highest plant was achieved at 50% shade level, while the highest leaf number and branch were 25% and 0%, respectively. Leaf thickness and stomata number increased in no-shade conditions. The production of phenolics and flavonoids was high under shaded conditions, supported by significantly high phenolics and flavonoid total under shade conditions, i.e., 35.94 mol gallic acid equivalent/plant and 21.76 mol quercetin equivalent/plant, respectively. A 90 kg/ha nitrogen fertilizer dose produced the best plant growth, phenolic, and flavonoid production. Keywords: Asteraceae, Heatmap, Nested design, Shade.

Evaluation of Nitrogen Fertilizer Doses on Several Corn Varieties Using UAV-Based Multi-Sensor Imagery

Evaluation of Nitrogen Fertilizer Doses on Several Corn Varieties Using UAV-Based Multi-Sensor Imagery

Response of Winter Wheat to Delayed Sowing and Varied Nitrogen Fertilization

Common wheat is one of the most important cereal crops in the world. In cultivation, winter, spring, and facultative varieties of this species are known. In wheat agronomy, timely sowing and optimal nitrogen fertilization are particularly crucial practices, as both significantly impact yield and grain quality. In a three-year field experiment, the response of the winter wheat variety RGT Kilimanjaro to two sowing dates (recommended and delayed by 30 days) and varied nitrogen fertilization levels (100 kg ha−1, 150 kg ha−1, and 200 kg ha−1) was investigated. It was shown that the difference in grain yield between 2021 and 2023 amounted to 0.74 kg ha−1. The application of 200 N kg ha−1 significantly increased the Soil Plant Analysis Development (SPAD) index and Leaf Area Index (LAI) compared to the variant with a delayed sowing date and a nitrogen dose of 100 kg ha−1. Yield components (number of spikes per square meter, thousand grain weight) and grain yield were highest when wheat was sown at the recommended date and with the application of either 150 or 200 N kg ha−1. The number of grains per spike significantly varied between the variant with the recommended sowing date and a dose of 200 N kg ha−1 and the variant with a delayed sowing date and a dose of 100 N kg ha−1. The lowest grain yield was obtained at a 30-day late wheat sowing date when applying 100 N kg ha−1. The protein content in the grain was primarily influenced by nitrogen fertilization. Therefore, it can be concluded that delaying the sowing date of winter wheat by 30 days results in a decrease in grain yield but can be compensated by increased nitrogen fertilization. The most favorable economic effects were achieved with the application of 150 N kg ha−1 at the recommended sowing date. Considering that high doses of nitrogen fertilization can have adverse effects on the natural environment, research in this area should be continued.

Estimation of Plant Height and Biomass of Rice Using Unmanned Aerial Vehicle

Plant height and biomass are important indicators of rice yield. Here we combined measured plant physiological traits with a crop growth model driven by unmanned aerial vehicle spectral data to quantify the changes in rice plant height and biomass under different irrigation and fertilizer treatments. The study included two treatments: I—water availability factor (i.e., three drought objects, optimal, and excess water); and II—two levels of deep percolation and five nitrogen fertilization doses. The introduced model is extreme learning machine (ELM), back propagation neural network (BPNN), and particle swarm optimization-ELM (PSO-ELM), respectively. The results showed that: (1) Proper water level regulation (3~5 cm) significantly increased the accumulation of spike biomass, which was about 6% higher compared to that under flooded conditions. (2) For plant height inversion, the ELM model was optimal with a mean coefficient of determination of 0.78, a mean root mean square error of 0.26 cm, and a mean performance deviation rate of 2.08. For biomass inversion, the PSO-ELM model was optimal with a mean coefficient of determination of 0.88, a mean root mean square error of 3.8 g, and a mean performance deviation rate of 3.29. This study provided the possible opportunity for large-scale estimations of rice yield under environmental disturbances.

UHPLC-Q-Orbitrap-HRMS-based untargeted metabolomics reveal metabolites change in Justicia gendarussa and its antioxidant capacity at different doses of nitrogen fertilizer.

This study delves into the antioxidant potential of Justicia gendarussa, commonly known as gendarussa, and its response to varying doses of nitrogen fertilizer. Gendarussa exhibits the potential for antioxidant activity. The diverse ecological conditions in which it thrives may influence its biological activity and lead to inconsistent production of secondary metabolites. Nitrogen, a pivotal factor in secondary metabolite production in plants, has become a focal point of this research. This research aims to determine the optimal nitrogen fertilizer dose on gendarussa antioxidant capacity and metabolites using a metabolomics approach. Employing a randomized block design for cultivation, the investigation revealed that a maximum harvest weight of 10.9 g/aerial parts of the plant was achieved with 270 kg/ha of nitrogen fertilizer. This study explored the DPPH, ABTS, FRAP, and CUPRAC assays of antioxidant effect, and found insignificant differences between the various nitrogen treatments. UHPLCQ-Orbitrap HRMS was employed to identify 30 metabolites in positive and 18 in negative ionization modes. Gendarusin A, a major metabolite in gendarussa, is identified in both positive and negative ionization. PCA and heatmap analysis successfully categorized these metabolites in the aerial parts of gendarussa at different nitrogen fertilizer dosages. Based on the metabolomics approach, variations in nitrogen fertilizer made metabolites at doses of 90 kg/ha had higher relative concentrations of metabolites compared to doses of 180 kg/ha and 270 kg/ha. So, 90 kg/ha are the optimal nitrogen fertilizer dose for cultivation and utilization strategies.

Desenvolvimento de helicônia em função de diferentes tipos de solo e doses de nitrogênio

Abstract Heliconia psittacorum is a plant that stands out in tropical floriculture due to its inflorescence with bracts of different colors and its high ornamental value. The aim of this study was to assess the influence of nitrogen applied under different management methods on the development of heliconia plants (H. psittacorum). The experiment was carried out in a greenhouse, in the soil science area, from May to December 2018, at the Belém Campus of the Federal Rural University of Amazonia (UFRA). A completely randomized design was used, in a 4 x 2 factorial scheme, distributed over 5 replications. The factors were 4 doses of nitrogen fertilization (0, 20, 40 and 60 kg ha-1 of N) and 2 types of soil (conventional cultivation and forest). The variables used to analyze the treatments were: height, pseudostem diameter, fresh weight of the pseudostem, flower stem, leaves, rhizome and root. The results of the experiment were subjected to analysis of variance, compared using the Tukey test, where appropriate, and regression studies by adjusting the equations according to the doses of N used. There were significant differences in all the variables studied. The results of this study show that there is probably a certain shortage of the elements needed for plant nutrition and, with a greater supply of N, there is greater root development to make up for this deficiency.

The effect of nitrogen fertilizer on the yield, structure and quality of quinoa (Chenopodium quinoa)

Field experiments were conducted in 2021-2022 at the Russian State Agricultural Academy named after K.A. Timiryazev (Moscow). The reaction of quinoa varieties (Chenopodium quinoa Willd.) to the use of various doses of nitrogen fertilizers was studied. The effect of nitrogen doses N60, N120, as well as the timing and frequency of their application on yield, crop structure, payback of nitrogen fertilizers when applied to culture and protein content in grain in agroecological conditions of the Central region of Russia has been established. Studies have shown that quinoa forms a higher yield and accumulates more protein in the grain when using nitrogen fertilizers. The use of fertilizers in a dose of N120 for fertilizing plants provides an average of 2.32 t, 2.50 t and 3.02 t/ha of Regalon, Vanilla Cherry and Titicaca grain varieties, respectively, for two years.

Long-Term Experiences with Fertilizers on Wheat and Maize Crops in the Pedoclimatic Conditions of the Bârlad Plateau

A large number of long-term field experiments demonstrate that optimal application of nitrogen fertilizers to crops did not result in loss of organic matter, nor did it adversely affect soil microbial activity. Optimal use of fertilizers on agricultural crops reduces soil erosion, but repeated application of high doses of nitrogen fertilizer can lead to soil acidification, a negative trait of soil health. The main objective of this paper is to study the particular effect, interaction and complementarity of NP, NPK and organo-mineral fertilizers on the production of agricultural crops. This paper presents production data as well as references that can be used to define the scientific bases of the multi-year application of fertilizers. The experimental technique is specific to the polyfactorial character and the analytical methods used are specific and current in the field. In this scientific paper, we present the results obtained for the cultivation of wheat and corn, during the period 2018-2023, at the “Mircea Moțoc” Perieni Research-Development Station for Combating Soil Erosion, by fertilizing with several types of organo-mineral fertilizers. The results obtained come from the long-term experiences with fertilizers with 25 variants in the NP experience, respectively 16 variants in the NPK experience and the organo-mineral experience, all being placed according to the block method with parcels subdivided into 6 repetitions. The obtained results were interpreted by analysis of variance. From the results of this long-term experience, it is concluded that the effect of long-term fertilization with NP, NPK and organo-minerals responds to the maximization of profit and the optimization of the soil-plant system and environmental protection.

Fertilizer management practices in potato cultivation: a baseline study for the introduction of GE potato in Bangladesh.

Genetically engineered (GE) crops have the potential to contribute to agricultural sustainability, food security, and nutritional enrichment. However, these crops cannot be released for commercial cultivation without undergoing environmental risk assessments (ERA), thus biosafety evaluation. ERA assessments are performed comparatively with their natural non-GE counterparts. As Bangladesh is progressing with GE potato research, the present study aims to collect baseline information on non-GE potato cultivation with an emphasis on current agronomic practices focusing on fertilizer management and farmers' knowledge base. The survey had three parts, including information on the farmers, information on potato cultivation practices, especially fertilizer use, and lastly, the farmer's view on GE potato. From 2020 to 2021, data were collected through interviews with experienced growers in four potato-growing regions, the Central and Mid-East, North-West, Mid-West, and South-East regions (n = 1757) of the country. The study revealed that farmers of all regions used more than the recommended amounts of fertilizer; for instance, 67.1% more nitrogen fertilizer was applied as an extra dose during potato cultivation in Munshiganj (Central and Mid-East) than in the Dinajpur region (North-West). This overuse of nitrogen fertilizer can enhance plant vigor but makes the plants more susceptible to insect attraction and allows pests easier access to the plants. As a result, the excess dose of nitrogen fertilizer in Munshiganj may act as a catalyst to increase the probability of late blight. The findings also showed that 73.6% of farmers observed unexpected flowering in certain potato cultivars, which corresponded to the higher application of phosphate and potassium fertilizers aimed at late blight control. Furthermore, this study reported infestations of Solanaceous weeds, specifically Solanum torvum and Physalis heterophylla, in potato fields. Finally, our findings demonstrated that more than 68.7% of the potato growers intend to adopt disease-resistant GE potato as that may reduce the need for excess fertilizer use and thus reduce cultivation costs.

Enhancing bulb yield through nitrogen fertilization and the use of hybrid onion (Alluim cepa L.) varieties in northwest Ethiopia.

Onions are among the most important cash crops in developing countries, including Ethiopia. However, its production and productivity are very low, which is associated with inappropriate fertilization and the use of low-yielding varieties. Therefore, the present study was conducted to evaluate the effects of the nitrogen fertilizer rate on the growth, yield, and quality of hybrid onion varieties in northwest Ethiopia. The experiment was conducted at three locations (Koga, Woreta, and Woramit) during the 2021/2022 cropping season under irrigated conditions. The treatments consisted of three hybrid onion varieties (Russet, Jambar, Red Coach) and one open-pollinated onion variety (Bombay Red) and four nitrogen rates (0, 41, 82, and 123 kg ha-1), which were laid out in a randomized complete block design with a factorial arrangement of 4*4 in three replications. The results of the present study revealed that onion growth, yield and quality were influenced by the nitrogen fertilizer rate and onion variety across all locations. Compared with the open pollinated Bombay Red variety, the hybrid varieties (Russet and Jambar) performed well in terms of bulb diameter, bulb weight, total yield, marketable bulb yield, and pungency. Nitrogen fertilizer applied at a rate of 82 kg ha-1 resulted in the highest growth and yield parameters of onion. The Russet and Jambar varieties recorded the highest marketable bulb yields of 26.50 t ha-1 and 24.57 t ha-1, respectively. Onion varieties treated with the highest nitrogen fertilizer dosage of 123 kg ha-1, particularly the Bombay Red variety, exhibited the longest duration to reach maturity. Onion plants supplied with 82 kg ha-1 nitrogen presented the highest marketable bulb yields, with a value of 26.77 t ha-1. Too much nitrogen above 82 kg ha-1 leads to decreased yield; hence, excess nitrogen is lost to the environment. Furthermore, the Jambar and Russet hybrid varieties and the application of 82 kg ha-1 nitrogen fertilizers provided the highest net benefit. The hybrid varieties Jambar and Russet and the application of 82 kg ha-1 nitrogen fertilizer can be recommended for onion production in the study area and areas with similar agroecosystems. Since this study is the first of its kind, considering other hybrid onion varieties and optimizing agronomic practices such as spacing and phosphorus fertilizer are also recommended in future research.

ПОЖИВНИЙ РЕЖИМ І ЗАБУР’ЯНЕНІСТЬ ПОСІВІВ СОРГО ЗЕРНОВОГО ЗА РІЗНИХ СПОСОБІВ ОСНОВНОГО ОБРОБІТКУ ҐРУНТУ ТА УДОБРЕННЯ

The article presents the results of experimental studies on the influence of different methods and depths of primary tillage, as well as nitrogen fertilizer rates, on the nutrient regime and weed infestation of grain sorghum crops. The research aims to scientifically substantiate and improve existing technological methods to increase the yield of grain sorghum plants, taking into account their morphobiological characteristics and reaction to the application of mineral fertilizers under various methods and depths of primary soil tillage. During the experiment, field, quantitative-weight, visual, laboratory, comparative-computational, and mathematical-statistical methods were used, employing widely recognized techniques and methodological recommendations. Results. The highest amounts of nitrates, mobile phosphorus compounds, and exchangeable potassium in the soil layer of 0-40 cm under grain sorghum crops during the years of the study were recorded against the background of the N60 nitrogen fertilizer dose applied during plowing to a depth of 28-30 cm. The lowest content of mobile phosphorus forms over the average of 3 years was observed in the disk tillage variant to a depth of 8-10 cm. The potassium content in the soil layer of 0-40 cm under grain sorghum crops over the average of 3 years of experimental research was characterized by a medium level. No significant difference was found in the utilization of available potassium by grain sorghum plants throughout the entire vegetation period, depending on the study factors. With an N30 dose, weed quantity increased by 1.4 and 2.2 times compared to the unfertilized background, depending on the soil tillage variant, and with an N60 dose, it increased by 1.3 and 2.1 times. The average yield of grain sorghum for plowing to a depth of 28-30 cm with the application of nitrogen fertilizers at a dose of N60 was 5.44 t/ha over the years of the study. For chisel tillage to the same depth, a yield of 3.89 t/ha was obtained, and for disk tillage, it was 2.54 t/ha. Conclusions. When growing grain sorghum in the conditions of the Southern Steppe of Ukraine, it is advisable to apply plowing to a depth of 28-30 cm against the background of nitrogen fertilizer application at a dose of N60, which creates favorable nutrient conditions and forms grain yield at the level of 5.44 t/ha. Keywords: grain sorghum, method and depth of tillage, nitrogen fertilizers, nutrient regime, weed infestation, yield.

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

IMPACT OF NITROGEN FERTILIZER ON THE PRODUCTIVITY AND QUALITATIVE PARAMETERS OF ANISE (Pimpinella anisum L.)

The present study investigated the effects of nitrogen fertilization on the yield and quality characteristics of Anise (Pimpinella anisum L.). The study was conducted in the ecological conditions of Kahramanmaras from 2019 to 2021. Two different anise populations Izmir (P1) and Konya (P2) and six different nitrogen fertilizer doses (0, 30, 60, 90, 120, 150 kg ha-1) were used in the study. The experiment was set up in triplicate using a split-plot design, with the populations on the main plots and the fertilizer doses on the subplots. Considering the herbal properties of anise grown in different nitrogen dose applications; plant height was 41.71- 42.75 cm, the total number of branches (10.62-12.50 plants-1), fruit branches (4.78-5.29 plants-1) and umbrellas (8.12-9.64 plants-1) were recorded. Considering the yield and quality characteristics; seed yield the range was 350.10- 400.02 kg ha-1, 1000-seed weight 2.78-3.49 g, protein rate 15.3-17.77%, fixed oil rate 15.15-16.34% fixed oil yield 50.51-60.48 kg ha-1, essential oil rate 1.66-2.26%, and essential oil yield 5.80-8.90 L ha-1. The Konya population had higher values in terms of seed yield and quality characteristics. With the exception of plant height, which revealed the total number of branches, fruit branches, umbels, seed yield, thousand seed weight, protein ratio, fixed oil ratio, fixed oil yield, essential oil ratio, and essential oil yield, all of the studied characteristics generally showed improvement with an increase in nitrogen doses. However, a nitrogen treatment of 120 kg ha-1 produced the maximum seed production.

The impact of Klebsiella quasipneumoniae inoculation with nitrogen fertilization on baby corn yield and cob quality

In response to the escalating costs and diminishing efficiency of nitrogen fertilizers, the agricultural community is actively seeking sustainable alternatives that leverage natural nitrogen sources derived from biological N-fixation processes to enhance crop yield. This study investigates the combined effects of Klebsiella quasipneumoniae inoculation and varying nitrogen fertilizer doses on soil fertility, nutrient availability, and the yield and quality parameters of baby corn (Zea mays. L). The study involved the application of five nitrogen levels (0, 75, 150, 225, and 300 kg N ha-1) in conjunction with Klebsiella quasipneumoniae inoculum on HM-4 variety of baby corn, employing a comprehensive experimental design with five treatments and four replications. All treatments demonstrated increased ear count and weights of ear, silk, husk, edible cob, and biomass compared to the control. The study highlights the potential of Klebsiella quasipneumoniae inoculation in synergy with reduced nitrogen fertilizer to enhance total N contents in soil and positively impact baby corn yield and cob quality parameters. Optimal results were achieved with a 50% reduction in nitrogen fertilizer (150 kg N ha-1), emphasizing the importance of integrated nutrient management. The findings contribute valuable insights to sustainable agriculture, offering a promising strategy for increased baby corn production, improved nutritional quality, and environmental conservation. This integrated approach, involving microbial inoculation and nitrogen management, emerges as a key element in modern agricultural practices, promoting both productivity and nutritional content in baby corn crops.

Influence of mineral fertilizers after-effect when cultivating barley after sunflower

The results of research for 2021, 2022 on the impact of the after-effect of different doses of mineral fertilizers applied to sunflower on productivity and quality of spring barley of the Kamashevsky variety are presented. Field experiments were laid in the conditions of the Ulyanovsk region on chernozem leached heavy loamy soil. Four backgrounds of mineral fertilizers were studied: N0, N30, N30P30K30, N60P30K30 kg a.i./ha Meteorological conditions were contrasting in the years of research, which allowed a more complete assessment of the effectiveness of fertilizer after-effect. Barley cultivation technology included spring cutting of sunflower crop residues with a discator and a modular harrow, sowing with a grain drill and rolling. Barley showed the greatest responsiveness to the after-effect of mineral fertilizers at a dose of N60P30K30 kg a.i./ha. Grain yield in this variant was 2.11 t/ha, which is 1.05 t/ha higher compared to the unfertilized variant. On this agricultural background, a larger grain was obtained (the weight of 100 grains was 48.4 g, on the control - 44.4 g) with a high protein content of 12.7% (on the control – 11.5%). Correlation and regression analysis revealed a direct positive relationship between dry matter accumulation and barley productivity (R2 = 0,96). It was found that with an increase in the dose of nitrogen fertilizers for every 10 kg a.i./ha, an increase in the crude protein content of grain by 0.2% was observed. Protein content in grain depended on the moisture conditions of the year. Cultivation of barley after sunflower is agronomically expedient on the background of mineral fertilizers aftereffect. In the absence of fertilizers, the productivity of barley after sunflower sharply decreases. In addition, it is necessary to carefully control the weediness of barley crops (including the emergence of large amounts of sunflower fallen seed) and timely chemical weeding.

Productivity of winter pea under the application of nitrogen fertilization and biological preparations in the Steppe of Ukraine

Purpose. To determine the elements of the yield structure and the level of crop productivity under the effect of the studied agronomic practices. Methods. Field, agrochemical and statistical methods were used in the study. Results. The results of experiments on the effect of nitrogen fertilization and biological preparations on the yield structure formation and the productivity of winter pea in the Steppe of Ukraine are presented. It was determined that the winter pea varieties ‘Enduro’ and ‘NS Moroz’ formed different plant densities: 78 plants/m2 and 77 plants/m2, respectively. With the application of biological preparations Leanum Humikor and Mycofriend, plant density increased by an average of 3%. The number of beans and seeds per plant and the weight of grain for the application of fertilizers in ‘Enduro’ was on average 11.3 and 30.6, respectively, and for the application of biological preparations 11.0 and 28.6, respectively. In ‘NS Moroz’, these indicators were 15.6 and 27.1, respectively, for the application of fertilizers and 15.5 and 27.1, respectively, for the application of biological preparations. The grain weight was 4.5–4.3 g in ‘Enduro’ and 4–3.8 g in ‘NS Moroz’. A high grain yield of 3.83 t/ha and 3.82 t/ha was obtained in both ‘Enduro’ and ‘NS Moroz’, respectively, after applying the Mycofriend + N40. In the treatments where the main fertilizers N10Р46К0 + N40 and N64Р46К0 + N40 were applied in spring, the yield was 3.15 t/ha and 3.08 t/ha in the ‘Enduro’ variety and 3.15 t/ha and 3.24 t/ha in the ‘NS Moroz’ variety, respectively. Conclusions. The application of biological preparations increased grain yield of winter pea compared to the use of additional doses of nitrogen fertilizers. The difference in grain yield between the fertilization options and the application of biological preparations was 0.67–0.74 t/ha in ‘Enduro’ and 0.59–0.68 t/ha in ‘NS Moroz’, respectively. To obtain high productivity of winter pea, the most effective agronomic practice is the application of fertilizers and biological preparations during autumn sowing, which helps to reduce the influence of changing soil and climate conditions in the period of plant organogenesis, and obtain optimum yield structure.

Morfofisiologia e trocas gasosas da romãzeira sob estresse salino e aplicação foliar de nitrogênio

ABSTRACT Salinity is one of the abiotic stresses that affect gas exchange and growth of pomegranate. In this context, the application of nitrogen fertilizer through the leaves can minimize these effects. Thus, the objective of present study was to evaluate the effect of foliar nitrogen fertilization on pomegranate seedlings irrigated with brackish water. The design used was randomized blocks, in an incomplete factorial scheme (Central Composite Design) with five electrical conductivities of irrigation water - ECw (0.50, 1.15, 2.75, 4.35, and 5.00 dS m-1) and five doses of foliar nitrogen fertilization - FNF (0, 0.33, 1.15, 1.97, and 2.30 g L-1), with four replicates and two plants per experimental plot. Plant height, number of leaves, stem diameter, and gas exchange (stomatal conductance, net photosynthesis, intercellular CO2 concentration, transpiration rate, instantaneous carboxylation efficiency, instantaneous water use efficiency, and intrinsic water use efficiency) were evaluated at 60 days after the beginning of irrigation with saline water. Salinity of irrigation water negatively affects the gas exchange of pomegranate seedlings. Foliar nitrogen fertilization up to 1.31 g L-1 improves plant height and number of leaves in pomegranate seedlings under salt stress. Foliar nitrogen fertilization up to 1.59 g L-1 increases the net photosynthesis of pomegranate seedlings.

Crop Yield and Balance of Nutrition Elements in the Grain-Steam Crop Rotation in the Conditions of the Dry Steppe of Buryatia

In the field agrochemical experiment, the potential of crop productivity and the balance of nutrition elements in the grain–steam crop rotation with alternating crops of steam–wheat–oats–oats per grain crop under conditions of increased aridization of the climate of the dry-steppe zone of Buryatia were investigated. It was revealed that the main application of N40P40 for grain crops and N40P40K40 for fodder (oats for grain planting) was the most effective among the mineral options and equal in effect and aftereffect to the application of manure 40 t/ha and organo-mineral fertilizer manure 10 t/ha + N50P25K60. A deficiency-free nitrogen balance was obtained when manure was applied at a dose of 11 t/ha of crop rotation area. The use of the recommended dose of mineral nitrogen fertilizers of 30 kg/ha did not compensate for nitrogen losses, its deficit was 12 kg/ha per year. A positive phosphorus balance was obtained when applying phosphorus fertilizers at a dose of 33 kg/ha, as well as the effects and aftereffects of manure 11 t/ha. The potash regime of soils in the experiment was the most deficient, the use of potash fertilizers (30 kg/ha of arable crop rotation), organic and organo-mineral fertilizers could not compensate for the loss of potassium in crop rotation.

Determination of Combined Effects of Organic and Mineral Fertilizer on Forage Yield and Quality of Annual Ryegrass

The widespread practice of using high doses of nitrogen to increase unit area yield in annual ryegrass introduces ecological and economic problems. This research was carried out over two years and aimed to determine the potential forage yield and quality of annual ryegrass by applying manure, humic acid, and low doses of nitrogen fertilizer, within the framework of sustainable forage crop cultivation. The study was carried out from 2020 to 2022 with three replications according to the randomized block split plots experimental design. According to the study results, the highest values were achieved with combinations that included manure application, and even higher values were observed when manure was applied along with low doses of humic acid and nitrogen. The M20 + H20 + N100 treatment yielded the highest fresh yield, dry matter, and crude protein. The treatments with manure, humic acid, and nitrogen fertilizer had varying effects on the ADF and NDF content of annual ryegrass, resulting in fluctuating values. In conclusion, 20 t manure, 20 L humic acid, and 100 kg ha−1 N application can be suggested for sustainable and higher dry matter production with good quality for annual ryegrass cultivation under semi-humid climatic conditions. The results obtained from this research hold promise for sustainable agricultural practices.