Stabilized Nitrogen Fertilizer Research Articles

Using the von Bertalanffy Model to Describe Ammonia Volatilization from Conventional and Stabilized Nitrogen Fertilizers in Coffee Crop System

ABSTRACT It has been increasingly important to control N-fertilizers, seeking high efficiency. This study aims to describe, using the von Bertalanffy model, the cumulative losses of nitrogen (N) by ammonia volatilization (NH3-N) from conventional and stabilized N-fertilizers applied in coffee orchard. The experiment was performed in Lavras municipality, Minas Gerais state, Brazil during the 2015/2016 coffee growing season. A randomized block design was used, with seven treatments (stabilized and conventional N-fertilizers) and three fertilizer applications. The evaluated stabilized and conventional N-fertilizers were: 1) prilled urea; 2) ammonium sulfate; 3) urea dissolved in water; 4) ammonium nitrate 5) urea + Cu + B; 6) urea + anionic polymer and; 7) urea + NBPT. Volatilization losses were evaluated, and the highest percentage of NH3-N losses occurred with prilled urea and urea + anionic polymer, with losses greater than 30% of N-applied depending on the number of installments. However, in the 2nd nitrogen fertilization, the von Bertalanffy model did not reach convergence for these treatments, which may have been influenced by the rainfall volume in the period. The lowest NH3-N losses were found for ammonium nitrate and ammonium sulfate, with losses that did not exceed 0.6%. The parameters were all significant and had biological interpretation, and the results will contribute to the development of more efficient fertilizers technologies for farmers. The von Bertalanffy model was adequate to describe the cumulative loss of N by volatilization of ammonia from conventional and stabilized N-fertilizers for coffee crop areas.

Evaluation of the Effect of Conventional and Stabilized Nitrogen Fertilizers on the Nutritional Status of Several Maize Cultivars (Zea mays L.) in Critical Growth Stages Using Plant Analysis

The study presents the results of a three year field trial aimed at assessing the nutritional status of maize in critical growth stages by means of a plant analysis in the cultivation of three maize cultivars differing in their agronomic and genetic profile. The main research problem was to demonstrate whether the availability of nitrogen from stabilized fertilizers for “stay-green” maize varieties is consistent with the dynamics of the demand for this component. This is very important from both the economic and agronomic aspect of maize cultivation. The research showed a significant response of the maize cultivars to different nitrogen fertilizer formulations, which was observed in the period from the five-leaf stage to the full flowering stage. The advantage of the fertilizer, UltraGran stabilo, over other nitrogen fertilizers in the BBCH 15 stage was demonstrated only for the cultivar, ES Metronom, which produced a greater aerial mass while maintaining the nitrogen concentration at the level of the other two maize cultivars. The nitrogen and potassium content shaped the kernel weight in the ear in the flowering stage, confirming the importance of the interaction of these two elements in forming this feature of maize as the main predictor of the grain yield. This trait (expressed by the R2 coefficient) manifested each year of the study, but especially in the years with optimal weather patterns (i.e., the first year). The response of the maize cultivars to nitrogen fertilizers, especially the cultivar, ES Metronom, was manifested by an increase in the content of nutrients and chlorophyll in the ear leaf, that is considered a predictive organ for grain yield. The fertilizers, Super N-46 and UltraGran stabilo, had a positive effect on the chlorophyll content (CCI parameter) and increased its efficiency of excitation energy transfer (the F0 parameter).

Slow and Controlled Release Nitrogen Fertilizers: Options for Improving Rice Productivity: A Review

Rice (Oryza sativa L.) is the most important food crop not only in Asia but also in the entire world. Over the past several decades, conventional fertilizer application for rice has caused the loss of nutrients, which could lead to a series of environmental problems such as eutrophication and greenhouse effects. The emergence of slow and controlled-release fertilizers provides a new option for more efficient fertilization of rice. International Fertilizer Association (IFA) included controlled release fertilizers (CRFs), slow release fertilizers (SRFs), sulphur coated urea (SCU), stabilized nitrogen fertilizers (SNFs), WSFs, liquid NPKs, and chelated micronutrients and boron in their assessment study of the global market for special products. In India, the specialty fertilizers are categorized broadly as water soluble fertilizers, neem coated urea, fortified fertilizers, customized fertilizers (CFs), micronutrient fertilizers, and liquid fertilizers. Controlled-release fertilizers, such as sulphur and/or resin coated urea, can reduce N losses (e.g. nitrogen leaching, ammonia volatilization), while increasing N availability in plant and enhance rice grain yield upto 22.1% in rice. These, slow release controlled fertilizer increase crop yields by maintaining soil health over time.

Effects of Fertilization on Growth and Productivity of Three Milk Thistle Populations


 Milk thistle is an important medicinal plant as it contains silymarin which has many pharmaceutical activities. The purpose of this study was to evaluate the influence of a stabilized nitrogen fertilizer alone or combined with a foliar fertilizer, containing phosphorous, potassium, iron, manganese, and zinc, on the plant development and fruit yield of three wild milk thistle populations originated from Greece. The fruits of the populations ‘Palaionterveno’, ‘Mesopotamia’, and ‘Spata’ were sown in plastic pots containing peat. Fertilization treatments were i) control - without application of fertilizer, ii) application of a stabilized nitrogen fertilizer, and iii) use of the stabilized fertilizer followed by applications of foliar fertilizer at three different growth stages. The results revealed that genetic material significantly affected the plant height, rosette diameter, and dry weight of root system. Moreover, the application of the nitrogen fertilizer alone or combined with a foliar fertilizer enhanced plant growth. Regarding the fruit yield, there was an interaction between the two factors.

Effects of different nitrification inhibitors on nitrification, maize yield, and nitrogen use efficiency in red soil.

We examined the effects of nitrification inhibitors (NIs) on soil nitrification, maize yield and nitrogen use efficiency (NUE), aiming to screen out high efficiency stabilized ammonium chloride fertilizer in red soil. Nitrification inhibitors 2-chloro-6-trimethyl-pyridine (CP), 3, 4-dimethyl-pyrazolate phosphate (DMPP), and dicyandiamide (DCD) and their combinations were added into ammonium chloride (NH4Cl) to make six stabilized nitrogen fertilizers. With blank (CK) and NH4Cl (N) as the controls, we conducted a maize pot experiment with the same amount of nitrogen addition. The results showed that compared with the treatment of N, soil ammonium content in CP+DMPP and DMPP+DCD increased by 56%-62%, which was significantly higher than that in CP, DMPP, and DCD, while the apparent nitrification rate of red soil was significantly reduced by 33%-34%. All the six treatments with nitrification inhibitors and their combinations significantly improved biomass and nitrogen absorption efficiency of maize. Compared with the N treatment, the application of adding NIs alone was significantly higher than that of the treatments of NIs combinations, with an average of 1.3 times increase. DCD was the most efficient one in improving maize yield, nitrogen uptake, and nitrogen adsorption efficiency, which increased by 4.1, 6.3 and 4.4 times, respectively. Comprehensively, DCD performed the best in reducing cost and improving yield and nitrogen use efficiency in red soil.

Yield and silymarin content in milk thistle (Silybum marianum (L.) Gaertn.) fruits affected by the nitrogen fertilizers

Milk thistle (Silybum marianum (L.) Gaertn.) is a common weed that has been introduced as a medicinal plant for silymarin production. This renders it important to optimize cultivation techniques, including fertilization. In the present study, a two-year field experiment was conducted to evaluate the influence of conventional and stabilized nitrogen fertilizers on plant growth, fruit yield, and fruit quality. The experiment was conducted in a randomized complete block design with five fertilization treatments (control, conventional nitrogen fertilizer applied at 75 kg/ha and 125 kg/ha, and stabilized nitrogen fertilizer applied at 75 kg/ha and 125 kg/ha. Nitrogen fertilization had a significant effect on vegetative and yield parameters. Specifically, the application of nitrogen fertilizers positively influenced rosette diameter, height, aboveground dry biomass, total chlorophyll content, number of capitula per plant, number of fruits per central capitulum, and fruit yield. In particular, in most traits, the usage of high nitrogen levels of the two types of fertilizer had the most pronounced impact. The application of the stabilized fertilizer at a rate of 125 kg N/ha induced an increase in fruit yield of up to 29.6 %. Nitrogen fertilization had no impact on the accumulation of oil and silymarin in the fruits, although some effects on oil and silymarin yield were noted. In general, the application of nitrogen fertilizers had no effect on the antioxidant activity or total phenolic content of the fruit extracts. Finally, climatic conditions affected the growth and productivity of milk thistle, as fruit yield was favoured by wet conditions.

Utility of stabilized nitrogen fertilizers to reduce nitrate leaching under optimal management practices

AbstractBackground: The inadequate application of nitrogen (N) to crops has increased the reactive N in the atmosphere and in the surface and ground waters. Stabilized N‐fertilizers with nitrification (NI) and urease (UI) inhibitors have been proposed to reduce these environmental problems without affecting or even increasing crop productivity.Aim: The objective of this study was to evaluate, in a maize–maize–wheat rotation, if the use of the NI 3,4‐dimethylpyrazole phosphate (DMPP) and the UIs N‐(n‐butyl) thiophosphoric triamide (NBPT) and monocarbamide dihydrogen sulfate (MCDHS) reduces N leaching without compromising yield under optimal management of N and water.Methods: The experiment was conducted in 24 drainage lysimeters with two soil types with contrasting water holding capacity under Mediterranean irrigated conditions. The fertilizer treatments were urea, urea with DMPP, urea with NBPT, and urea with MCDHS. For the maize crop, conventional fertilizer application was split into 6‐ and 13‐leaf stages, whereas stabilized fertilizers were applied as a single application at the 6‐leaf stage. All fertilizer treatments were applied at late tillering in the wheat crop.Results: The soil mineral N was measured at the beginning and the end of each crop season, but no differences were found among fertilizer treatments. Differences in the volume of water drained or the cumulative mass of nitrate depending on the fertilizer were not significant (three‐year treatment average of 200 L m−2 and 22 kg N ha−1 in the Deep soil, and 334 L m−2 and 40 kg N ha−1 in the Shallow type, respectively). No consistent significant differences were found in agronomic parameters (chlorophyll measurements, yield, and total N uptake) between the fertilizer treatments.Conclusion: Based on the results, the use of stabilized N‐fertilizer could be recommended to reduce the number of N applications in maize without compromising grain yield but with no advantages to reduce nitrate‐leaching losses if N rates are managed properly under efficient irrigation management practices.

Yield-scaled N<sub>2</sub>O and CH<sub>4</sub> emissions as affected by combined application of stabilized nitrogen fertilizer and pig manure in rice fields

A field experiment was conducted to study the effects of stabilized nitrogen fertilizer combined with pig manure on rice yield and nitrous oxide (N<sub>2</sub>O) and methane (CH<sub>4</sub>) emissions. Four treatments were established: urea (U); pig manure (PM); PM and urea (PM + U); PM and stabilized nitrogen fertilizer (urea plus 1% NBPT (N-(n-butyl) thiophosphoric triamide), 1% PPD (phenylphosphorodiamidate) and 2% DMPP (3,4-dimethylpyrazole phosphate)) (PM + U + I). In this study, compared with PM, PM + U significantly increased cumulative N<sub>2</sub>O emission, but PM + U + I showed no significant difference from PM on N<sub>2</sub>O cumulative emission, indicating that stabilized nitrogen fertilizer combined with PM is effective at reducing N<sub>2</sub>O emissions. The cumulative emission of CH<sub>4</sub> from PM + U + I treatment was significantly lower than that from PM and PM + U, indicating that stabilized nitrogen fertilizer combined with PM can effectively reduce CH<sub>4</sub> emissions as well. The yields of PM + U and PM + U + I were not significantly different from those of U and PM, indicating that local conventional nitrogen application and returns of PM can provide sufficient nitrogen for rice growth. For yield-scaled emissions (YSE), PM was the highest, while PM + U + I significantly decreased YSE. Concomitant application of stabilized nitrogen fertilizer can achieve the goal of reducing YSE when PM is returned to the field.

Use of Natural Nitrogen Stabilizers to Improve Nitrogen use Efficiency and Wheat Crop Yield

Abstract Complex nature of nitrogen fertilizer in soil and poor management practices are major causes of low fertilizer use efficiency in Pakistan. These factors further increases nitrogen losses in form of nitrate leaching and volatilization of ammonium, as well as nitric oxide which are burning economic and environmental threats. Keeping in view the demand of urea application in Pakistan and its low efficiency, we hypothized that appropriate urea management with neem formulations or biofertilizers can enhance the nitrogen use efficiency. We designed experiment with treatments: T0 (N0 application), T1 (recommended nitrogen), T2 (recommended nitrogen + biofertilizer), T3 (recommended nitrogen + neem seed extract), T4 (75% recommended nitrogen + biofertilizer), T5 (75% recommended nitrogen + neem seed extract), T6 (recommended nitrogen + biofertilizer + neem seed extract), T7 (75% recommended nitrogen + biofertilizer + neem seed extract) in wheat crop. The experiment was laid out in randomized complete block design (RCBD) with split plot arrangements. Different approaches for stabilized nitrogen fertilizer responded significantly for the wheat plant height, tillers per plant, number of grains per spike, 1000-grain yield, grain yield and harvest index. Result exhibited that wheat crop enhanced yield attributes and finally the yield under treatment T6 and T7 for both wheat cultivars. Treatments comparison with recommended nitrogen (T1) revealed that all treatments with biofertilizer, as well as with neem seed, enhanced crop performance along with nitrogen use efficiency. It can be concluded that nitrogen fertilizer can be stabilized in the soil with the use of different natural products for sustainable crop production.

Can stabilized nitrogen fertilizer sources reduce losses through multiple loss pathways?

This article looks at two recent reviews that highlight the effectiveness of stabilized nitrogen fertilizers in reducing N2O emissions in Midwest corn production. Are these findings consistent with other research in a wider geography or other cropping systems? What are the impacts of stabilized nitrogen sources on other nitrogen losses? What are the effects on crop yields? Earn 0.5 CEUs in Nutrient Management by reading this article and taking the quiz at www.certifiedcropadviser.org/education/classroom/classes/607.

Eco-innovations in the German fertilizer supply chain: Impact on the carbon footprint of fertilizers

The aim of this paper is to analyse to what extent the existing eco-innovations in the German fertilizer domain might reduce the fertilizer carbon footprint without compromising on crop productivity. The continuously growing demand for agricultural products will require a further increase in agricultural production mostly achieved with additional external inputs (fossil energy, pesticides, irrigation water and fertilizers). Fertilizer in general and nitrogen fertilizers in particular are major factors for yield increases in crop production. On the other hand, emissions of greenhouse gases play a dominant role in the debate on the environmental burden of fertilizers. Typical mineral fertilizers were compared with so-called stabilized nitrogen fertilizers and secondary raw material fertilizers in this study. Additionally, an effect of the combination of irrigation with fertilization (i.e. fertigation) was investigated. With an adopted life cycle assessment approach focusing on CO<sub>2</sub> and N<sub>2</sub>O emission, the carbon footprints of the different fertilizer options were considered. The calculations showed that especially the use of stabilized nitrogen fertilizer reduced the fertilization-related carbon footprint up to 13%. However, because of higher costs or incomplete supply chain relationships, adoption of these innovations is expected to be rather limited in the near future. Fertilizers made from secondary raw materials resulted in similar carbon footprints as mineral ones, but they can help to close nutrient cycles and use by-products of other production processes.

The Effect of Limestone and Stabilized Nitrogen Fertilizers Application on Soil pH Value and on the Forage Production of Permanent Grassland

The changes of soil pH and dry forage yield of permanent grassland after application of dolomitic limestone and stabilized nitrogen fertilizers are described in this paper. The small‑plot experiment was located on semi‑natural grassland at Bohemian‑Moravian Highlands, near village Kameničky (Czech Republic), with poor and acidic soil. The experiment was divided into two blocks, within one of whose dolomitic limestone was applied in autumn 2013. In each block, 4 experimental treatments were applied: 1. control (untreated), 2. Urea, 3. Urea with inhibitor of urease, 4. Urea with inhibitor of nitrification. After liming, the pH/CaCl2 soil values increased in both the first as well as the second year after application. Fertilizing by urea, namely urea with inhibitors, did not significantly influence the pH/CaCl2 values. Dry forage productions in both years were comparable. In comparison to the untreated variants, significant increase in dry forage yield was achieved after application of urea and urea with urease inhibitors. The impact of stabilized fertilizers on the yield was not proven. In case of the limed variants, yield drop by 1.12 t/ha (average of both years) was observed; the yield decrease may be connected with disturbance of production potential of the stable community of plant species that had been adapted to acidic locations.

Slow-release stabilized nitrogen fertilizers on initial development and nutrition of coffee plants (Coffea arabica L.)

Currently there is interest in aggregating technology to fertilizers in order to increase their efficiency. A good example is the use of slow and steady release nitrogen fertilizers. This study was conducted in a greenhouse to evaluate the efficiency of stabilized, slowrelease nitrogen sources in the early development and nutrition of coffee plants (Coffea arabica L.). The treatments followed a factorial 6 × 3 being: six nitrogen fertilizer sources (conventional urea – CU; ammonium nitrate – AN; elemental sulfur coated urea US; elemental sulfur coated urea and polymer - USP; urea combined with organic material - UO, and UO + NBPT - UONBPT); three application times, with four replications. The experiment was conducted for 150 days and the aerial part dry mass production (APDM), that of the leaf (LDM), plus the foliar N concentration and content were evaluated. The use of stabilized slow-release N fertilizers influenced (APDM) and (LDM) production as well as the foliar N concentration and content in coffee plants. The N content in the leaves followed the order: UONBPT <UO <USP <US < AN <CU, contrary to the beneficial effects regarding N availability of fertilizers with associated technology in relation to the conventional source - Urea.

Productivity of irrigated beans due to sources of stabilized nitrogen fertilizer and controlled release

ABSTRACT New nitrogen fertilizers are available in the market actually, however, does not have results on the efficiency of the Cerrado conditions. With that objective of this study was to evaluate the effect of urea including stabilized and controlled release urea on yield of irrigated common beans (Phaseolus vulgaris L) in no-tillage system. The experiment was conducted in the winter crop, at Embrapa Arroz e Feijão, in Santo Antônio de Goiás, State of Goiás, Brazil. The experimental design was randomized blocks, with five replicates. Treatments consisted of five N sources (urea, urea + NBPT, urea + polymer, ammonium sulphate, and ammonium nitrate) and a control (without N) being applied 20 kg ha-1 of N at sowing and 80 kg ha-1 onf N in topdressing. We evaluated the chlorophyll content in leaves of common beans, the leaf N content and dry mass weight (MSPA) in the flowering of common beans, the number of pods per plant, number of grains per pod, mass of 100 grains, grain yield and final stand of the common beans. The sources of nitrogen fertilizer did not influence, leaf N content, the mass of MSPA and the relative chlorophyll index of common beans. The use of polymerized urea and urea with urease inhibitor, did not produce increases in the number of grains per pod, number of pods per plant, mass of 100 grains and common beans yield compared to traditional sources of N, urea, ammonium sulfate and ammonium nitrate.

Stabilized Nitrogen Fertilizers and Application Rate Influence Nitrogen Losses under Rainfed Spring Wheat

Nitrogen losses associated with fertilizer application have negative economic and environmental consequences, but urease and nitrification inhibitors have potential to reduce N losses. The effectiveness of these inhibitors has been studied extensively in irrigated but not in rainfed systems. This study was conducted at Glyndon, MN, under rainfed conditions to assess the impact of urease and nitrification inhibitors on NH3 volatilization, N2O emissions, and NO3− concentrations below the spring wheat (Triticum aestivum L.) rooting zone. Urea (U), urea with urease and nitrification inhibitors (SU), and urea with nitrification inhibitor only (UI) were applied at 146 and 168 kg N ha−1 along with the control treatments. Cumulative NH3 volatilization was reduced by 26%, N2O emissions measured 18 d after planting were reduced by 50% with SU, but no significant reduction was observed with UI compared to U. We did not observe a significant effect of higher N rate on N2O emissions, but lower N application rate (146 kg N ha−1) significantly reduced NH3 volatilization by 26% compared to 168 kg N ha−1. Nitrate concentration below the rooting zone was reduced by applying N at lower rate and also through the use of SU and UI instead of U. Soil inorganic N intensity was significantly related with cumulative N2O emissions. Nitrogen source and rate did not influence grain yield and protein content. This single‐growing season study under rainfed conditions suggests that fertilizer N‐stabilizers can be successfully used to minimize N losses without compromising grain yield and protein content.

Influence of stabilized nitrogen fertilizer use on yield, nutrient uptake and soil quality under maize-wheat sequence in Uttar Pradesh

Field experiments were conducted to study the impact of stabilized N fertilizer on yield, nutrient uptake and soil quality under maize-wheat cropping sequence at Fertilizer Research Farm, Uttaripura, Kanpur Nagar (U. P.), Chandra Shekhar Azad University of Agriculture & Technology, Kanpur during 2010–11 and 2011–12. Results indicated that grain and straw yield of maize-wheat significantly increased with the use of different urea A Lab over (T1) urea lab 8041 (plain urea). Significant increase in yield of maize-wheat was also noted within each urea A Lab up to urea A Lab 8044. The highest grain yield of maize and wheat was noted 33.15 and 56.75 q/ha, respectively, with urea A Lab 8045 (T6). The per cent response in grain of maize-wheat at T6 over T2 was noted (6.75 and 10.25 q/ha) with corresponding per cent response 25.56 and 22.04, respectively. Nutrient uptake (NPK) also significantly increased with various urea A Lab over urea Lab (T2). Protein content in both maize and wheat positively responded with the use of different urea A Lab over urea Lab. The response of various urea A Lab 100% was almost at par with 125% urea Lab 8046 (plain urea).

Release, movement and recovery of 3,4-dimethylpyrazole phosphate (DMPP), ammonium, and nitrate from stabilized nitrogen fertilizer granules in a silty clay soil under laboratory conditions

In model experiments under laboratory conditions the release of 3,4-dimethylpyrazole phosphate (DMPP; ENTEC), NH4 +-N, and NO3 –-N from the ENTEC-fertilizer granules placed on a silty clay soil was studied. The air-dried soil contained in Petri dishes was moistened to 18% or 24% water holding capacity, and incubated for 10 days at 4°C, 15°C or 25°C after placing the granules in the centre of the plates. Plates without granules served as controls. At appropriate intervals, soil cores were taken at 5–20 and 25–40 mm distance from the granules and analysed for DMPP, NH4 +-N and NO3 –-N. Amongst the three fertilizer ingredients, NO3 – was found to be the most mobile showing a fairly uniform distribution in both soil zones during 10 days of incubation. Under the different temperature and moisture conditions, more than 80% of DMPP remained within the 0- to 5-mm region around the granule. Between 5% and 15% of DMPP was found in the 5- to 20-mm region, and <3% moved into the 25- to 40-mm region. Increasing temperature and moisture facilitated the movement of DMPP in soil. NH4 + diffused faster than DMPP and showed a recovery of up to 13% in the 25- to 40-mm region under the given conditions. NH4 + was separated from the DMPP within 10 days, as revealed by an increase in the NH4 +-N to DMPP ratios. An intensive N2O flux was observed within the 5- to 20-mm zone of the fertilizer granules, which was ascribed to heterotrophic denitrification rather than nitrification.