scholarly journals Kinetics of calcium Cyanamid obtaining process from lime, carbon dioxide and ammonia

2020 ◽  
Vol 3 (9) ◽  
pp. 260-263
Author(s):  
O.Kh. Panjiev ◽  
A.Kh.Panzhiev

In Uzbekistan, the main range of nitrogen fertilizers produced is ammonium nitrate, carbamide and ammonium sulfate, the use of which has led to acidification of millions of hectares of land for many years, which negatively affects the receipt of high yields of agricultural crops

The results of studies on the influence of forms and doses of nitrogen fertilizers (ammonium nitrate, urea, carbamide-ammonia mixture, ammonium sulfate) on the productivity of oil flax under the conditions of the western forest-steppe are given. In the traditional system of fertilizer, oil flax is not able to provide high yields and quality products. An effective solution to this is optimization of plant nutrition due to its balance, which promotes intensive plant development, makes it possible to actively and efficiently intervene in the process of harvesting and its quality. Therefore, determining the optimal fertilizer rate for oil flax in specific soil-climatic conditions is important for obtaining stable and high yields of culture. The purpose of our research was to determine the contribution of doses and forms of nitrogen fertilizers to the productivity of flaxseed oil in the soil-climatic conditions of the western forest-steppe. The research was carried out in 2016-2018 at the experimental field of the Institute of Agriculture of the Carpathian region of NAAS in five-point crop rotation with the total area of the plant growing on a gray forest surface glued type of soil In general, four forms of nitrogen fertilizers were studied: ammonia, nitrate, carbamide-ammonia mixture, urea and ammonium sulfate, which were added in doses: N30; N45 one time; and N30 + N15 under pre-sowing cultivation and in the "fir tree" phase against the background of P30K60. The total number of variants was 16. The object of research was a variety of flax oilseed crops of breeding of the Institute of Oilseeds of NAAS. The seed sowing rate is 6 mln similar seed per hectare. According to the results of three-year studies, the effect of intensification of mineral nitrogen feed and various forms of nitrogen fertilizers on the indices of the elements of productivity and yield of flaxseed oil has been established. In particular, it was found that their use had little effect on the density change of plant stem growth. The use of nitrogen fertilizers in the dose N45 on the background of P30K60 improved plant survival (killed during the vegetation of 0.33-0.42 million pp./ha, which is 5.2-6.3 % for control, where the death observed 0.58 million ppm/ha or 8.4 %)) compared to the N30 dose (0.39-0.49 million pcs/ha). In addition, the use of the dose N45 separately (N30 under cultivation + N15 in the phase of the "fir tree") also improved the survival rate of plants (5.2-5.8 % of dead plants) compared with the simultaneous application of N45 cultivation (5.6-7.1 %) The percentage of deaths grew in control (without fertilizers) - 8.4 % against the background of P30K60 - 7.0 %. The application of various forms and doses of nitrogen fertilizers led to an increase in the control of the elements of productivity. The introduction of N45 against the background of P30K60 contributed to an increase in the number of boxes on plants, according to the variants of fertilizers, this index varied from 14.6 to 18.3 pieces per plant (10.9 - on the control, 12.9 pcs/roll - on the РК background), increasing the amount of seeds per plant by 12.7 pc. per plant, a mass of 1000 seeds per 0.2-0.3 g compared with the control and 0.1-0.2 g compared with the LCD background, where this figure was 6.8 g. On average, over the years of research, the highest productivity of flax seed of oilseed Vodograi (2,27 and 2,48 t / ha) was obtained provided the mineral fertilizer N15P30K60 was applied for cultivation in combination with carbamide feed in the phase of "fir tree" at a dose of N15. When using the nitrogen component in the form of KAS, the gain to control was 1.45 t / ha, to the background - 1.12 t/ha. In control and against the background, this indicator was 1.04 and 1.36 t/ha respectively. When using other forms of nitrogen fertilizers on the background of P30K60, lower yields of flaxseed crops were obtained (1.37-1.38 t/ha). The introduction of the N45 separately (N30 under cultivation + N15 into the "fir tree" phase) generally led to higher performance than a single application for cultivation. Among the studied forms of fertilizers, urea and carbamide-ammonia also caused a slightly higher percentage of fiber content in flax stems, however, it was within the experimental error and was not significantly increased.


1981 ◽  
Vol 11 (2) ◽  
pp. 414-422
Author(s):  
C. Camiré ◽  
B. Bernier

Six nitrogen fertilizers (urea, sulfur-coated urea, urea-formaldehyde, ammonium nitrate, ammonium sulfate, and ammonium nitrate) were individually applied, either in fall or in spring, at a rate of 224 kg N/ha and compared for nitrogen retention in the different horizons of a podzol under jack pine. Despite its susceptibility to nitrogen losses through ammonia volatilization, urea was by far, among readily available nitrogen fertilizers, the one whose nitrogen is best retained in soil surface horizons. Retention varied with weather conditions that prevailed immediately after fertilizer application. With the other fertilizers used, nitrogen retention followed this order: ammonium sulfate > ammonium nitrate > calcium nitrate. After four seasons, about 50% of the nitrogen applied as sulfur-coated urea and urea-formaldehyde was still found in its original form. Ammonium sulfate is next to urea among the recommended nitrogen sources for similar jack pine sites, considering that fertilizers with nitrate are prone to leaching and the sulfur-coated urea and urea-formaldehyde used presented problems of nitrogen availability.


1981 ◽  
Vol 11 (2) ◽  
pp. 423-432 ◽  
Author(s):  
C. Camiré ◽  
B. Bernier

Fall or spring applications of six different nitrogen fertilizers (urea, sulfur-coated urea, urea-formaldehyde, ammonium nitrate, ammonium sulfate, and calcium nitrate) at a rate of 224 kg N/ha in an 18-year-old jack pine stand induced a very rapid increase of nitrogen concentration in current year and 1-year-old needles, as well as in weight of current year needles. In the latter, nitrogen content (concentration × weight) increased more than 100% the 1st year following fertilization in the ammonium sulfate and the ammonium nitrate treatments applied in spring. Response did not last more than 2 years. Foliar analysis of other elements (P, K, Ca, Mg, and Mn) revealed a reduction of P concentration in the needles sampled the first fall after treatment together with a reduction of Ca and Mn in the current foliage of the second and third seasons after treatment. Changes in nitrogen concentration in Kalmiaangustifolia L. and particularly in Solidagopuberula Nutt. were in good correlation with those observed in jack pine needles.


2017 ◽  
Vol 41 (5) ◽  
pp. 494-510 ◽  
Author(s):  
Taylor Lima de Souza ◽  
Douglas Ramos Guelfi ◽  
André Leite Silva ◽  
André Baldansi Andrade ◽  
Wantuir Filipe Teixeira Chagas ◽  
...  

ABSTRACT The market of stabilized, slow and controlled release nitrogen (N) fertilizers represents 1% of the world fertilizer consumption. On the other hand, the increase in availability, innovation and application of these technologies could lead to the improvement of N use efficiency in agroecossystems and to the reduction of environmental impacts. The objective of this study was to quantify agronomic efficiency relative index, ammonia volatilization, and CO2 emissions from conventional, stabilized and controlled release N fertilizers in corn summer crop. The experiment was carried out in a corn crop area located in Lavras, state of Minas Gerais, Brazil, without irrigation. All treatments were applied in topdressing at rate of 150 kg ha-1 N. N-NH3 losses from N fertilizers were: Granular urea (39% of the applied N ) = prilled urea (38%) > urea coated with 16% S0 (32%) = blend of urea + 7.9% S0 + polymers + conventional urea (32%) > prilled urea incorporated at 0.02 m depth (24%) > urea + 530 mg kg-1 of NBPT (8%) = Hydrolyzed leather (9%) > urea + thermoplastic resin (3%) = ammonium sulfate (1%) = ammonium nitrate (0.7%). Thermoplastic resin coated urea, ammonium nitrate and ammonium sulfate presented low values of cumulative CO2 emissions in corn crop. On the other hand, hydrolyzed leather promoted greater C-CO2 emission, when compared with other nitrogen fertilizers.


Horticulturae ◽  
2021 ◽  
Vol 7 (9) ◽  
pp. 285
Author(s):  
Vladimir Zebec ◽  
Miroslav Lisjak ◽  
Jurica Jović ◽  
Toni Kujundžić ◽  
Domagoj Rastija ◽  
...  

Nitrogen fertilizer efficiency in grapevine production is an important objective for solving the trade-off between improving yield and quality in agroecosystems and reducing environmental impacts. Influence of soil nitrogen fertilization and Fe foliar application on iron dynamics in soil and grapevine leaves of the ‘Graševina’ cultivar on carbonate soil was conducted in a two-year study in 2018 and 2019. The experiment was settled in three replicates on a total of seven fertilization treatments that differed in used form of nitrogen fertilizer and foliar application of Fe before and after the flowering of the grapevine: control (C); calcium ammonium nitrate (KAN); calcium ammonium nitrate + foliar Fe (KAN+F); ammonium sulfate (AS); ammonium sulfate + foliar Fe (AS+F); ammonium sulfonitrate + foliar Fe (ASN+F); urea + foliar Fe (U+F). Mineral fertilization with acid-forming nitrogen fertilizers (AS and ASN) significantly affected local acidification of alkaline soil, i.e., reducing the actual and exchangeable soil pH reaction, which resulted in increased soil Fe availability. Despite the increase in soil iron availability, no increased iron bioaccumulation in the grapevine leaves was found in the flowering and veraison stages at treatments where foliar fertilization was omitted. Of all the observed treatments, only foliar fertilization had a positive effect on iron concentration in the grapevine leaves, which leads to the conclusion that this is an effective way to solve iron deficiency symptoms and chlorosis occurrence. The use of mineral fertilizers with acid-forming nitrogen fertilizers for many years can result in a reduction of required foliar treatments and thus significantly affect the ecological and economic aspects of grape production. Thus, integrated iron management is needed to meet the needs of the grapevine for this micronutrient and to reduce the occurrence of leaf chlorosis in carbonate soil.


1981 ◽  
Vol 11 (2) ◽  
pp. 433-440 ◽  
Author(s):  
C. Camiré ◽  
B. Bernier

Six nitrogen fertilizers (urea, sulfur-coated urea, urea-formaldehyde, ammonium sulfate, ammonium nitrate, and calcium nitrate) were individually applied, either in fall or in spring, at a rate of 224 kg N/ha and compared for their effects on growth distribution along the stem, height increase, basal area increase, and volume increase of an 18-year-old jack pine stand during 5 years after treatment. The response to nitrogen treatments was maximum the 2nd and 3rd years after fertilization and became nil in the fifth season. The distribution of growth along the stem varied with the height considered, the maximum being observed in the first 3 m aboveground. Treatments that responded best in terms of increase in basal area (2 m2/ha or 34% higher than control) and in volume (10 m3/ha or 21% higher than control) were urea and ammonium sulfate applied in fall, and ammonium nitrate applied in spring. Regression analysis on principal components revealed that growth the year before treatment and nutrient concentrations in foliage (N, P, K, Mg, Ca, and Mn) explain at least 80% of the observed growth variations on a 5-year basis.


1983 ◽  
Vol 48 (12) ◽  
pp. 3340-3355 ◽  
Author(s):  
Pavel Fott ◽  
Pavel Šebesta

The kinetic parameters of reactivation of a carbonized hydrodesulphurization (HDS) catalyst by air were evaluated from combined thermogravimetric (TG) and differential thermal analysis (DTA) data. In addition, the gaseous products leaving a temperature-programmed reactor with a thin layer of catalyst were analyzed chromatographically. Two exothermic processes were found to take part in the reactivation, and their kinetics were described by 1st order equations. In the first process (180-400 °C), sulphur in Co and Mo sulphides is oxidized to sulphur dioxide; in the second process (300-540 °C), in which the essential portion of heat is produced, the deposited carbon is oxidized to give predominantly carbon dioxide. If the reaction heat is not removed efficiently enough, ignition of the catalyst takes place, which is associated with a transition to the diffusion region. The application of the obtained kinetic parameters to modelling a temperature-programmed reactivation is illustrated on the case of a single particle.


Agronomy ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 844
Author(s):  
Carlos Martín Sastre ◽  
Ruth Barro ◽  
Yolanda González-Arechavala ◽  
Ana Santos-Montes ◽  
Pilar Ciria

Nitrogen fertilizers have been identified in energy crops LCAs as the main contributors to global warming, as well as to many other environmental impacts. The distinct production process and application emissions of nitrogen fertilizer types for top dressing produce different GHG savings when energy crops value chains are compared to fossil energy alternatives. In this study, three types of fertilizers (calcium ammonium nitrate, urea and ammonium sulphate) at N top dressing rates of 80 kg N/ha are used to grow rye for electricity generation under the conditions of the Continental Mediterranean climate of central-northern Spain. Complete LCAs for the whole value chain based on real data were performed in conjunction with soil nitrogen balances (SNBs) to assess the accomplishment of European Union (EU) GHG savings sustainability criteria, as well as the sustainability of fertilization practices for soil nitrogen stocks. The results obtained can provide interesting insights for policy making, since calcium ammonium nitrate, the most common fertilizer for rye crops, led to 66% GHG savings, as opposed to the 69% achieved when applying urea and 77% when ammonium sulphate was used. Nevertheless, the three fertilizers produced annual soil deficits greater than 50 kg N/ha. In order to ensure savings above 80%, as required by the EU sustainability criteria, and sustainable SNBs, additional optimization measures should be taken at key points of the value chain.


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