Different Doses Of Nitrogen Fertilizer Research Articles

Inoculation of bacterial consortium increases rice yield (Oryza sativa L.) reducing applications of nitrogen fertilizer in San Martin region, Peru

Rice feeds more than 50% of the population worldwide, representing a great energy contribution in low-income families. The exaggerated use of synthetic chemical fertilizers to maintain high levels of yield causes alterations in the physical, chemical and biological quality of the soils. A sustainable alternative is the use of beneficial microorganisms that promote plant growth in crops. The objective of the study was to isolate and evaluate the Plant Growth Promoting (PGP) traits of rhizospheric rice bacteria in soils of the San Martin region, evaluate the effect of promoting growth in rice under pot experiments conditions and finally evaluate the effect of selected strains on the yield under different doses of nitrogen fertilizer under field conditions. Initially, 27 strains were selected for their diazotrophic characteristics and characterized by PGP traits. Through a multivariate analysis of main components, five strains were selected and evaluated in pot experiments. In this stage, the rice seeds were inoculated with the five selected strains at the rate of 109 CFU g−1 and were evaluated at 135 days. The strains showed that the parameters such as Shoot Dry Weight (SDW), tillering and grain quality were superior and even similar between inoculated treatments receiving doses of 50% Nitrogen (N) (75 kg N ha−1) and treatment receiving full dose (150 kg of N ha−1). For the field experiments, Burkholderia ubonensis la3c3, Burkholderia vietnamiensis la1a4 and Citrobacter bitternis p9a3m were selected, which were inoculated in a consortium at a rate of 109 CFU mL−1 in the nursery stage and at the time of transplantation. Grain yield was higher but not significant between 2.5 and 13.5% in inoculated treatments receiving 75% and 100% (150 kg N ha−1) of the nitrogen fertilizer dose compared to the treatment without inoculation and without fertilization. Grain quality was superior in inoculated treatments versus non-inoculated treatments, reaching specific increases of 32.8% (N), 45.5% (P) and 27.9% (K) in inoculated treatments receiving low doses of N fertilizer (25%) versus treatment receive a full dose of fertilizer, also a significant increase of 2.5% in the percentage of whole grain, with respect to mill quality. The rentability (14.7–88.6%) and the utility (17.7–94.1%) were also higher in inoculated treatments. It is concluded that the use of selected native bacterial consortiums reduces the use of nitrogen fertilizer by up to 25%, increasing the productivity of rice cultivation in the San Martín region.

Поживний режим чорнозему вилугуваного та продуктивність зернової ланки за тривалого удобрення сівозміни

Goal. To study the effect of legumes predecessors and doses of nitrogen fertilizers on the nutritive regime of leached chernozem in agrocenose of winter wheat as well as grain chain productivity at long-term (over 50 years) application of different systems of organomineral fertilizing in conventional and alternative crop rotations. Methods. Long-term field and analytical. Results. Changes were fixed of the nutrient status of leached chernozem in agrocenose of winter wheat and productivity of grain link at the long-term application of organic and mineral fertilizers in crop rotation, as well as at introduction of different doses of nitrogen fertilizers under winter wheat, and its further cultivation after different legumes predecessors. The data were got concerning the content of mobile forms of nutrients in leached chernozem and their impact on the productivity of grain link. It was established that the fund of mineral nitrogen in soil depended mainly on the doses of nitrogen fertilizers which were entered under winter wheat, as well as on the legumes predecessor. The reserves of mobile phosphorus and potassium in leached chernozem depended on the duration and background of organic and mineral fertilizers which were used in crop rotation. Conclusions. The best conditions of the nitric mode of leached chernozem in agrocenose of winter wheat were formed for its cultivation after clover with the use of mineral fertilizers in the dose of N60P60K60. Fund of mobile phosphorus in the soil in agrocenose of winter wheat was formed mainly due to long-term (over 50 years) application of organic and mineral fertilizers in crop rotation. An annual application of 64 kg pf phosphorus (N43P43K43 + 8,3 t of manure for 1 ha of the area of crop rotation) with fertilizers (for 1 ha of crop rotation) had formed a high level of availability of soil phosphorus in the range of 309–323 mg/kg. That exceeded the control without fertilizer on 133–138 mg/kg of soil. Such a fertilizing system stabilized in crop rotation the content of mobile potassium in the soil at the level of 102–123 mg/kg. That corresponded to the average level of benefit and exceeded the control without fertilizers on 29–43 mg/kg of soil. The highest productivity of the grain crop rotation was achieved at the use of clover as the predecessor and long-term (50 years) entering of N43P43K43 + 8,3 tons of manure (or by-products) per 1 ha of crop rotation: yield of fodder units — 8.02 t/ha, the yield of grain — 3,33 t/ha of the link of crop rotation.

Оптимізація біологічних процесів трансформації органічної речовини у чорноземі вилуженому

The purpose. To study features of emission of nitrous oxide from leached chernozem under the influence of increasing doses of fertilizers and receipt of fresh organic substance of various parentage; to determine necessary amount of carbon for optimization of biological processes at use of solid mineral fertilizers. Methods. Field experiments, gas-stratographic analysis, agrochemical, computational. Results. Specific losses (g N-N2O/kg C-CO2) of nitrogen from soil are diminished at manuring (dung, straw, mass of Lupine green manure crop and their combinations). The greatest specific losses of N-N2O in experiments were registered in alternatives with fertilizers. At the same time application of solid mineral fertilizers in low (100 kg/hectare a.a. in the link of crop rotation) and average (200 kg/hectare a.a.) doses on the background of straw (5 t/hectare) and Lupine green manure crop (13 t/hectare) secured decrease of indexes (even below control). That testified to fixation of part of mineral nitrogen compounds not used by plants. Thus for optimization of C/N ratio it is not required additional application of mineral nitrogen. Combination of the highest dose of fertilizers in experiment (300 kg/hectare in the link of crop rotation) with straw and green manure crop does not allow to lower specific losses of nitrogen to the level of control. That testifies to redundancy of mineral nitrogen in soil in that case. The formula of calculation of necessary amount of carbon for optimization of C/N ratio is offered at use of different doses of nitrogen fertilizers in crop production technologies. It ensures balance of mineralizing and synthetic processes in soil. Conclusions. Application of calculated doses of fresh organic substance (dung, straw, Lupine green manure crop and their combination, including mineral fertilizers) secures optimization of microbiologic processes in agro-ecosystems at cultivation crops on leached chernozem. In such conditions the nitrogen of mineral joints not used by plants metabolically linked (immobilized) by microorganisms. Emission of N2O, and doses of fertilizers, which do not exceed 200 kg/hectare a.a. in crop rotation, decreased, and became environmentally sound.

Production of annual ryegrass with different doses of nitrogen fertilization in topdressing

The objective of this study was to assess the growth of annual ryegrass (Lolium multiflorum) cv. BRS Ponteio with different doses of nitrogen applied in the pasture, thereby adjusting their growth to the exponential growth model. A randomized block design was used with five nitrogen application rates (0, 150, 250, 350, and 450 kg N ha-1) and four replicates, applied in installments. Each plot measured 9 m2. On April 15, 2014, 25 kg ha-1 of viable pure seeds of annual ryegrass were sown at a depth of 0.02 m, in 18 rows spaced at 0.17 m in each plot. Growth in the control treatment (zero nitrogen) pasture lasted 167 days with only three cuts, whereas in pastures treated with 350 and 450 kg N ha-1, growth was extended for an additional 45 days with a 333% increase in the number of cuts. The pastures were used for the same duration (188 days) in the treatments with 150 and 250 kg N ha-1, however, increased nitrogen resulted in two additional cuts and a shorter time interval between cuts. The time interval between each cut and the degree-days interacted dynamically causing distinct growth. Growth of the annual ryegrass BRS Ponteio without nitrogen application is poor and cannot be represented even by a first order linear model. The application of nitrogen topdressing, in the form of urea, decreases the time interval between cuts, increases the dry matter production per hectare, stimulates this production, and follows the exponential growth model.

ИЗУЧЕНИЕ ИЗМЕНЧИВОСТИ СОРТОВ РИСА ПО АМИЛОГРАФИЧЕСКИМ ХАРАКТЕРИСТИКАМ КРАХМАЛА ЗЕРНА В СВЯЗИ С ИСПОЛЬЗОВАНИЕМ РАЗЛИЧНЫХ ДОЗ АЗОТНЫХ УДОБРЕНИЙ ПРИ ВОЗДЕЛЫВАНИИ

ИЗУЧЕНИЕ ИЗМЕНЧИВОСТИ СОРТОВ РИСА ПО АМИЛОГРАФИЧЕСКИМ ХАРАКТЕРИСТИКАМ КРАХМАЛА ЗЕРНА В СВЯЗИ С ИСПОЛЬЗОВАНИЕМ РАЗЛИЧНЫХ ДОЗ АЗОТНЫХ УДОБРЕНИЙ ПРИ ВОЗДЕЛЫВАНИИ

The dependence of the biochemical composition of soybean seeds on different doses of nitrogen fertilizer and sowing density

The dependence of the biochemical composition of soybean seeds on different doses of nitrogen fertilizer and sowing density

Morphogenic, structural, productive and bromatological characteristics of Braquiária in silvopastoral system under nitrogen doses

his study aimed to evaluate the effect of different doses of nitrogen fertilization on the morphogenic, structural, productive and chemical composition of Urochloa decumbens (Stapf) R. D. Webster cv. Basilisk in a silvopastoral system with eucalyptus. The experimental treatments consisted of pastures of Basilisk cultivar, fertilized with 0, 100, 200, 300 and 400 kg ha-1 year-1 of N, and intercropped with eucalyptus, clone GG 100 (Eucalyptus grandis x E. urophylla). The experimental arrangement followed a randomized block design with four replicates. The evaluated characteristics were: foliar appearance rate, phyllochron, leaf length, leaf elongation rate, leaf life span, foliar senescence rate, number of green leaves per tiller, number of senescent leaves per tiller, daily dry matter accumulation, dry matter production, crude protein, and neutral detergent fiber. In the conditions of the established silvopastoral system, nitrogen fertilization did not influence (p > 0.05) the morphogenic and structural characteristics of Basilisk cultivar, except for height (p < 0.01) and leaf: stem ratio (p = 0.02). The nitrogen fertilization of the Brachiaria grass with eucalyptus in the proposed structural arrangement does not modify (p > 0.05) the morphogenic characteristics. However, in ration to dry matter production, doses of up to 400 kg of N ha-1 are recommended.

Nitrogen Fertilization on Maize Sowing: Plant Growth and Seed Vigor

The management of fertilization in maize plants is a preponderant factor in the search for higher yields and obtaining quality seeds. In this sense, the study of nitrogen (N) management is predominant in improving the efficiency of its application. The objective of this study was to evaluate the growth, partition assimilation and vigor expression of maize seeds submitted at different doses of nitrogen applied at sowing. The treatments were constituted by different doses of nitrogen fertilization at sowing, being: 25%, 50%, 75% and 100% of the recommended dose for the crop, according to the recommendation of nitrogen fertilization. The plants were collected at regular intervals of 21 days after sowing until the end of the growth cycle. For the analysis of growth and partition of dry matter between the organs, the accumulation of dry matter and leaf area was measured. The experimental design was randomized blocks in a 4 × 7 factorial scheme (four N rates at sowing and seven collection times with three replications). The maize plants under the influence of nitrogen fertilization at sowing presented differential growth and distinct responses in the assimilated partition between their structures, with the intensity dependent on the dose used. Plants grown using 75% of the recommended dose of N at sowing had a higher relative growth rate, with more pronounced effects compared to the other doses. The expression of maize seed vigor increases to an increase of 82.5% N at sowing.

Effect of growth stages and fertility levels on growth, yield and quality of fodder oats (Avena sativa L.)

A field experiment was conducted to evaluate the yield and quality parameters of oats (Avena sativa L.) at forage research farm in Punjab Agricultural University, Ludhiana. Four different nitrogen levels viz. 0 (control), 50, 75 (recommended) and 100 Kg N/ha were applied in the form of urea. Samples were collected at three different growth stages i.e. 30, 45 and 60 DAS. As the growth of plant continued decrease in total nitrogen (45%), non protein nitro-gen (37%), ether extract (13%), ash content (24%) and digestibility (23%) was observed. But increase in free amino acids (48%) and cell wall constituents i.e. ADF (19%), NDF (31%) and CF (34%)with plant’s growth was reported. The interactive effect of varying levels of inorganic fertilizer application on the chemical composition of the plant at various growth stages revealed an increase in total nitrogen (18%), non protein nitrogen (26%), ether extract (18%), free amino acids (32%), ash content (13%) and digestibility (7%) with increase in fertilizer level however ADF (7%), NDF (2%) and CF (3%)content decreased with increased levels of nitrogen fertilization. Correlation studies showed that significant negative correlation was present forin vitro dry matter digestibility with acid detergent fiber (r= -.861**), neutral detergent fiber (r= -.891**) and crude fiber (r= -.740**) at recommended dose of N fertilization. The objective of this study was to investigate the effect of different doses of nitrogen fertilization at different growth stages on quality components in oats fodder.

Response of Two Local Rice Cultivars to Different Doses of Nitrogen Fertilizer in Two Paddy Fields

The study aimed to determine the response of two local rice cultivars subjected to different doses of nitrogen (N) fertilizer in two paddy fields, namely Petung and Gunung Makmur in Penajam Paser Utara, East Kalimantan. The research was arranged in Nested Design with five doses of N fertilizers, two cultivars, and two locations as treatments. The doses of N fertilizers were 0, 25, 50, 75 and 100 kg N.ha -1 nested in two cultivars (Nanung and Pance Kuning) and two locations (Petung and Gunung Makmur). Each treatment was conducted in three replicates. The result showed that the Pance Kuning cultivar was superior than Nanung in Petung location in terms of the number of tillers per hill, number of productive tillers per hill, percentage of filled grain per panicle, weight of 1000 grains and potential yield. A different effect of N fertilizer was observed on the number of tillers per hill, percentage of filled grain per panicle and weight of 1000 grains. Nanung and Pance Kuning showed positive responses to the application of 75 kg N.ha -1 in Petung for the parameters of tiller number and weight of 1000 grains.

Wplyw wieloletniego nawozenia azotem i obornikiem na zmiany wybranych wlasciwosci materii organicznej gleby lekkiej

The aim of the research was to assess the effect of long-term application of different doses of nitrogen fertilizers with or without manure to changes in the total organic carbon content, total nitrogen content, evaluation of dissolved organic carbon content and the value of absorbance coefficient (A4/6) in sandy loam soil. The base of research was the long-term field experiment, established in 1979 at the Wierzchucinek Experimental Station close to Bydgoszcz city - Poland. The experiment was carried out in the three-course crop rotation, potato, rye, rye in randomized split-plot design. The experimental treatments were four levels of N fertilizers in 0, 47, 93, and 140 kg∙ha-1∙yr-1 (N0, N1, N2, N3) as a 1st factor of experiment, and the same doses of N fertilizers with farmyard manure application (30 t∙ha-1) as a 2nd factor. After 36 years of experiment the content of total organic carbon was 26% lower and the content of total nitrogen 13% higher compared to the values determined before the experiment foundation (1979). The consequence of changes in the content of organic carbon and total nitrogen, are changes in the ratio of organic carbon content and total nitrogen content. It was noticed that the use of manure and different nitrogen doses resulted in a decrease of organic carbon content and total nitrogen content value. After application of different nitrogen doses, organic carbon content ranged from 122.4 to 152.2 mg∙kg-1. The same nitrogen doses applied simultaneously with farmyard manure increased the organic carbon content, which ranged from 133.5 to 166.7 mg∙kg-1. The changes of the organic carbon content did not effect on percentage of this fraction in the total organic carbon. Percentage of organic carbon content in total organic carbon content was on averaged 1.6%. After the application of different nitrogen doses, humic acids of analyzed soils were characterized by lower average value of A4/6 (5.4). However, the application of nitrogen doses with manure brought a higher - 6.3 - A4/6 value. Farmyard manure application caused the formation of humic acids of lower molecular weight and a low humification degree.

ВЛИЯНИЕ АЛЛЕЛЕЙ ГЛЮТЕНИНКОДИРУЮЩЕГО ЛОКУСА GLU1B НА ХОЗЯЙСТВЕННО-ЦЕННЫЕ ПОКАЗАТЕЛИ ПШЕНИЦЫ ПРИ РАЗНЫХ ДОЗАХ АЗОТНЫХ УДОБРЕНИЙ

ВЛИЯНИЕ АЛЛЕЛЕЙ ГЛЮТЕНИНКОДИРУЮЩЕГО ЛОКУСА GLU1B НА ХОЗЯЙСТВЕННО-ЦЕННЫЕ ПОКАЗАТЕЛИ ПШЕНИЦЫ ПРИ РАЗНЫХ ДОЗАХ АЗОТНЫХ УДОБРЕНИЙ

Effects of root pruning and fertilization on biometric traits of 2-year-old seedlings of European beech (Fagus sylvatica L.)

Abstract The aim of this study was to examine the effects of pruning the root system and different doses of nitrogen fertilization on the height and root collar diameter of 2-year-old beech seedlings (Fagus sylvatica L.). This research was conducted in the forest nursery Muchów (Jawor Forest District, regional directorate of State Forests in Wrocław) and two different pruning treatments (no pruning and at 12 cm depth) and nitrogen fertilization doses (25 and 50 kg×ha−1) were applied. Results from an ANOVA showed statistically significant differences between the two pruning treatments (p = 0.000) as well as for the interaction of both treatment factors (p = 0.019). Root collar diameter correlated with seedling height, both of which were significantly different for the two pruning treatments (p = 0.000). No statistically significant impact by the nitrogen fertilization doses on seedling height could be observed (p = 0.125). To conclude, we found that it is reasonable to reduce the doses of nitrogen fertilization to half the recommended amount, 25 kg×ha−1, if the root system is not pruned during the second growth year. Seedlings that do receive pruning should be fertilized using the recommended nitrogen doses.

Dual purpose wheat production with different levels of nitrogen topdressing

Currently, the practice of Crop-Livestock Integration is stimulated as a way of increasing the generation of foreign exchange for Brazil. Integrated systems improve land use efficiency as well as preserve, recover and increment or soil fertility. The aim of this research was to evaluate how different doses of nitrogen fertilization can affect production and quality of dual purpose wheat submitted to grazing. The experimental designed was randomized block with five treatments (0, 75, 150, 225 and 300 Kg N ha-1, like ammonium nitrate) and four repetitions. The forage yield, the percentage crude protein (P=.0001) and acid detergent insoluble protein (P=.0054) had a linear increased because of the nitrogen addition doses. The crude protein percentage changed the estimate of all soluble carbohydrates (P=.0001) and non-fibrous carbohydrates (P=.0186), but did not influence the, nitrogen detergent fiber corrected with ash and proteins percentage contributing for content cell. The crops production (P=.0001) and the number of kernels per ear (P=.0001) showed significantly difference because of the nitrogen additions dose, increasing the number of fertile flowers. The nitrogen topdressing alters forage production, the chemical composition and the production of dual purpose wheat grains subjected to grazing.

Effects of rates of nitrogen on yield and yield components of winter triticale

Due to the high genetic potential for yield and favourable nutritional value, triticale is a promising plant species. For achieving high and stable yields, it is necessary to have favorable agroclimatic conditions of the locality, variety and advanced agricultural techniques, with special emphasis on fertilizing. This study examines the effect of increasing rates of nitrogen on yield and yield components of five cultivars of winter triticale: Odisej, Kg-20, Triumph, Rtanj and Tango. The three-year trial (2009-2012), which was set up in a randomized block system with three replications, included control and three different doses of nitrogen fertilization (0, 60, 90 and 120 kg ha-1). In all variants of fertilization, 80 kg ha-1 P2O5 and K2O were added beside nitrogen. The obtained results showed that the use of nitrogen had a positive effect on yield and yield components in all variants and in all cultivars. The variety Tango had the highest average grain yield, while the variety Kg-20 had the lowest. Also, Tango had the highest value of the 1000 grain mass and the number of grains per spike, while Triumph had the highest value of hectoliter weight. The application of fertilizers led to a very large and significant increase of yield compared with the control. Accordingly, all studied cultivars had the highest yield with the highest quantities of nitrogen (120 kg ha-1). Considering that triticale is intended mainly for feeding livestock, the results of these studies would be valuable in terms of its growing as a forage crop as well as in terms of its breeding for grain quality and productivity.

The effect of different levels of nitrogen fertilizer on the growth and yield of coffee trees (Coffea arabica L.)

A study was carried out at the experimental farm of the Agriculture Faculty, Ibb University, Yemen, during (2011-2013). This study aims at investigating the effect of different doses of nitrogen fertilizer on the growth and yield of coffee trees. The treatments were applied using humus 2kg/tree as control (T1), nitrogen fertilizer as urea with different doses 6g/tree (T2), 13g/tree (T3), and 19.6 g/tree (T4). Tri-superphosphate (5g), potassium sulfate (5g) and humus (2kg) /tree were added to all treatments except of the control. A randomized complete block design was used. The study period was two years, the morphological characters and coffee productivity were studied. As shown in the results in the 1st year, the height’s gain of trees were increased in T4 and T2. Concerning the gain of branches number, they were increased in all treatments, with no significant differences among treatments. In the 2nd year, the gain of height was highly increased in T4 (72.38) followed by T3 and T2 (65.45 and 61.55 cm, respectively) compared with T1 (54.95). A high significant difference (p≤ 0.05) on the gain of height between T4 and T1 was observed. The gain of branches number was significantly (p≤ 0.05) increased in T4 (25.8 ) as compared to T1, T3 and T2 (20.9, 19.9 and 19.6). The coffee yield was the highest in T3 (703.3 g/tree) followed by T4 (676.4 g/tree).

Resposta da cultura da linhaça ao nitrogênio

This study aimed to verify the phenotypic responses when subjected to different doses of nitrogen fertilizer in the form of urea, to development of culture flaxseed. The experiment was conducted in Cascavel in the state of Parana / Brazil. Treatments considered were: T1: control, T2: 25, T3: 50 and T4: 75 kg ha-1 N as NH3. The planting was carried out in an area of 2.56 m2. After 120 days of culture were carried out analyzes of the following variables length of plant, number of capsules, fresh weight and dry weight of shoot, the parameters evaluated varied according to the amount of fertilizer applied. Normal 0 21 false false false PT-BR X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:Tabela normal; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-parent:; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:Calibri,sans-serif; mso-bidi-font-family:Times New Roman;}

Урожайность овсяницы тростниковой и ежи сборной на увлажненных местах при разном уровне азотного питания

В статье приведены данные по влиянию различных доз азотных удобрений на урожайность злаковых трав (ежу сборную и овсяницу тростниковую), которая в среднем достигала 98 - 119,7 ц/га сухой массы с окупаемостью 1 кг азотных удобрений 22 - 24 кг.

Nutritional and Physiological Response of Wheat to Soil Applied Matrix-I Formulated Calcium Carbide with and Without Nitrogen Fertilizer

Calcium carbide is well known as a nitrification inhibitor and its role as a source of ethylene (C2H4), a potent plant growth regulator, is not thoroughly investigated. A pot trial was conducted to evaluate the effectiveness of formulated calcium carbide with different doses of nitrogen fertilizer on nitrogen use efficiency, growth and yield of wheat. At the 1st step calcium carbide was formulated with polyethylene and plaster of paris and named as Matrix-I (21% calcium carbide, 58% polyethylene and 21% plaster of paris). Wheat cv. Inqulab-91 seeds were sown in pots and 5 plants were maintained. Calcium carbide was applied @ 0, 7.5, 15 and 22.5 mg/kg pot soil with 0, 30 and 60 mg N/kg soil. It was noted that nitrogen fertilizer application significantly enhanced almost all growth and yield parameters of wheat. It was also observed that matrix-I not only improved growth and yield parameters of wheat except plant height, which was reduced by CaC2 application, but also enhanced N uptake by different plant parts of wheat, when applied @ 15 mg CaC2 kg soil at 8 cm soil depth. It was further noted that matrix-I better improved N use efficiency when applied -1 with half recommended dose of N fertilizer than that of with full recommended N fertilizer rate.

The influence of cultivation systems on weed infestation in spring barley.

Each tillage system, regardless of its intensity affects the soil environment and has some advantages and disadvenges. It also may increase or slowdown degradation processes and thus affect agroecosystem quality. Reduced tillage besides (its) advantages suchas including reducing erosion, slowing down mineralization of organic matter and reducing energy inputs alsomany result in a higher risk of weed infestation. A higher crop competitiveness against weeds can be achieved by using green manures and increased nitrogen fertilization. The aim of studies in the two-factor field experiment was to determine changes in weed infestation of spring barley under different tillage systems with increasing rates of nitrogen fertilizer. Different tillage systems significantly affected weed infestation of spring barley. No significant differences of weed infestation under the different doses of nitrogen fertilization were stated.