Yield and chlorophyll index in cabbage in function of enhanced-efficiency nitrogen fertilizers and urea

2020 ◽  
Vol 13 (2) ◽  
pp. 6
Author(s):  
J. J. Frazão ◽  
A. R. Silva ◽  
F. H. M. Salgado ◽  
R. A. Flores ◽  
E. P. F. Brasil

The increase of the efficiency of the nitrogen fertilization promotes reduction of the applied dose and decreases the losses of nitrogen (N) to the environment. The objective of this work was to evaluate the yield and the relative chlorophyll index (IRC) in cabbage crop under cover fertilization, using enhanced-efficiency nitrogen fertilizers, compared to urea, in variable doses. The experimental design was randomized blocks in a 3x4+1 factorial scheme (three sources, four rates and control), with four replications. The N sources used were: common urea (U), urea treated with urease inhibitor NBPT® (UN) and Kimcoat® polymer coated urea (UK). The N rates used were 0, 40, 80, 160 and 320 kg ha-1, divided in two fertilizations at 20 and 40 days after transplantation. Up to 160 kg ha-1 of N, there was no difference between N sources and N rates for both yield and RCI. The enhanced-efficiency N sources (UN and UK) promoted higher averages compared to common urea, possibly due to the higher N losses from common urea. Thus, the use of urease inhibitors or polymers associated with urea is a promising strategy to improve cabbage yield, as well as reducing N losses to the environment.

Author(s):  
Gabriel B. da Silva Júnior ◽  
Eduardo M. dos Santos ◽  
Roberto L. Silva ◽  
Ítalo H. L. Cavalcante

ABSTRACT As a strategy to minimize N losses in the soil, mineral N sources, such as polymer-coated urea, have been studied as possibility to increase the synchronization of N release by the fertilizer and its absorption by plants. Thus, this study aimed to evaluate the contents of macronutrients and the production of Formosa papaya as a function of sources and doses of N fertilizer applied as top-dressing in the region of Bom Jesus-PI, Brazil. The treatments were arranged in a 2 x 4 factorial scheme corresponding to N sources (coated urea and conventional urea) and N doses (350, 440, 530 and 620 g plant-1 of N), with four replicates and four plants per plot. The contents of macronutrients in the leaf dry matter and fruit production were evaluated. The sources and doses of top-dressing N fertilization incremented the leaf contents of macronutrients and the production of Formosa papaya hybrid Caliman 01. Under the experimental conditions and based on the macronutrient contents considered as adequate for crop nutrition, associated with maximum fruit production (8.08 kg plant-1), the supply of 525 g of N plant-1 is recommended in the form of coated urea.


Author(s):  
Wadson de Menezes Santos ◽  
Bruno José Rodrigues Alves ◽  
Segundo Urquiaga ◽  
Edson Patto Pacheco ◽  
Inácio de Barros ◽  
...  

Abstract: The objective of this work was to evaluate the effect of the use of different nitrogen fertilizers on N losses by NH3 volatilization and on the grain yield of a corn (Zea mays) crop grown in the semiarid region of the state of Sergipe, Brazil. Corn was managed under rainfed conditions and conventional tillage. The fertilization treatments were: sulfur-coated urea (SU) and organo-mineral-coated urea (OMU). Regular urea and ammonium sulfate (AS) were also included as a reference of N sources of high and low NH3-volatilization potential, as well as a control without N fertilization. The N sources were applied to the soil surface at a rate of 150 kg ha-1 N as side-dressing at the V5 growth stage of corn. The experiment was carried out in 2015 and repeated in 2016. Losses of N through NH3 volatilization differed among the N sources in the two study years, with AS presenting the lowest N losses and regular urea, the highest. In the area treated with OMU, losses by NH3 volatilization were consistently controlled, showing a reduction of 74 and 67% in relation to that of regular urea in both years. SU, however, only mitigated NH3-N losses in 2015, increasing them in 2016, compared with regular urea. Corn plant grain yield and N status, assessed by the index leaf, did not clearly reflect N losses by NH3 volatilization. For the semiarid of Sergipe, OMU is the best urea-based fertilizer to mitigate N losses by NH3 volatilization, and the use of AS is an alternative to increase corn yield and eliminate N losses as NH3.


2017 ◽  
Vol 48 (1) ◽  
Author(s):  
Thais Antolini Veçozzi ◽  
Rogério Oliveira de Sousa ◽  
Walkyria Bueno Scivittaro ◽  
Cristiano Weinert ◽  
Victor Raul Cieza Tarrillo

ABSTRACT: A study was conducted to evaluate the solubilization and nitrogen (N) use efficiency (NUE) of controlled release nitrogen fertilizers in irrigated rice, compared to urea. It was developed under semi-controlled conditions, including five treatments: Control, Splitted Urea (pre-sowing and topdressing), Pre-sowing urea, and Polymer Coated Urea (PCU) with 60-day and 90-day release. PCUs did not maintain high NH4 + and NO3 - levels in solution over a longer period than urea. NUE of PCUs was similar to uncoated urea, not increasing nutrient release in irrigated rice field.


Nativa ◽  
2020 ◽  
Vol 8 (4) ◽  
pp. 579-584
Author(s):  
Hamilton César de Oliveira Charlo ◽  
Juliano da Silva Martins de Almeida ◽  
Valdeci Orioli Júnior ◽  
Regina Maria Quintão Lana

O objetivo deste estudo foi avaliar o efeito de doses e modos de aplicação de N, fornecido por meio de ureia revestida, no estado nutricional e produção de alface americana. Utilizou-se o delineamento em blocos ao acaso em arranjo fatorial 6x4 + 1, sendo seis doses de N (28,75; 57,50; 115,00; 172,50; 230,00; 287,50 kg ha-1 de N), como fonte a ureia revestida, e quatro modos de aplicação do nutriente (100% da dose no transplante; 50% no transplante + 50% aos 10 dias após o transplante (DAT); 25% no transplante + 75% aos 10 dias DAT; 25% no transplante + 25% a cada cobertura, aos 10, 20 e 30 DAT). No tratamento adicional utilizou-se a ureia convencional. Foram determinados os teores foliares de N, P, K, Ca e Mg, a massa fresca total e comercial da cabeça, o diâmetro do caule, a altura da planta e o diâmetro da cabeça aos 30 e 60 dias após o transplante. Verificou-se que a adubação nitrogenada aumentou os teores foliares de N, Ca e Mg, e reduziu os teores foliares de K e P. Não houve influência das doses de N proveniente de ureia revestida com polímero e dos modos de aplicação nos atributos morfológicos e produtivos da cultura. Palavras-chave: Lactuca sativa L.; nitrogênio; fertilizante de liberação lenta; fertilizante de liberação controlada.   RATES AND APPLICATIONS WAYS OF POLYMER-COATED UREA IN CRISPHEAD LETTUCE CULTIVATION   ABSTRACT: The aim of this study was to evaluate the effect of N rates (using a polymer-coated urea) and N application ways in nutritional status and yield of crisphead lettuce. The randomized block design in a 6 x 4 + 1 factorial arrangement was used, with six N rates (28.75, 57.50, 115.00, 172.50, 230.00, 287.50 kg ha-1 of N), with the use of polymer-coated urea, and four nutrient application ways (100% of the transplant rate, 50% at the transplant + 50% at the 10 days after the transplant (DAT), 25% at the transplant + 75% at 10 days DAT, 25% at transplant + 25% at each side dressing fertilization at 10, 20 and 30 DAT). The additional treatment was related to the recommended N fertilization using conventional urea. N, P, K, Ca and Mg, total and commercial yield, stem diameter, plant height and head diameter were determined at 30 and 60 days after transplant. Nitrogen fertilization increased the N, Ca and Mg foliar levels, independently of the application way. However, in general, it reduced the leaf levels of K and P. There was no influence of N rates from polymer-coated urea and application way on the morphological attributes and yield of the crop. Keywords: Lactuca sativa L.; nitrogen; slow-release fertilizer; controlled-release fertilizer.


2021 ◽  
Author(s):  
Adeel Ahmad ◽  
Muhammad Yaseen ◽  
Hafiz Naeem Asghar ◽  
Shahzad Maqsood Ahmed Basra

Abstract Nitrogen (N) fertilizer application is a very important commodity in agricultural systems. However, due to the losses of applied N from the soil microenvironment its efficiency is too low. Different strategies like the use of polymer coating and use of chemical nitrification inhibitors had been employed to reduce N losses. But these chemical nitrification inhibitors are very expensive. Thus, a study was conducted to investigate the effects of different concentrations of parthenium extract, neem oil and acidulated cow dung compost extract on N dynamics in the soil. Three concentrations of parthenium extract (5, 10 and 15 %) and neem oil (1, 2 and 3 %) were coated on urea granules after mixing with the polymer material. Three pH (2, 4 & 6 pH) based acidulated cow dung compost extracts were also coated on urea granules in the same pattern. These coated fertilizers and uncoated urea were applied in jars filled with soil (100g per jar) at the rate of 1g of fertilizer per jar. One treatment was kept as control (without any fertilizer). Treatments along three replications were arranged according to the completely randomized design (CRD). Results depicted that all coating materials caused the release of N consistently from applied fertilizers compared to uncoated treatment. In addition, percent nitrified N was also reduced significantly in coated treatments in comparison to the uncoated urea and control treatments. However, the level of concentration effect was not obvious as lower concentrations of these extracts and oil also performed almost equal to that of higher concentrations.


2014 ◽  
Vol 38 (4) ◽  
pp. 1200-1206 ◽  
Author(s):  
Eduardo Zavaschi ◽  
Letícia de Abreu Faria ◽  
Godofredo Cesar Vitti ◽  
Carlos Antonio da Costa Nascimento ◽  
Thiago Augusto de Moura ◽  
...  

A form of increasing the efficiency of N fertilizer is by coating urea with polymers to reduce ammonia volatilization. The aim of this study was to evaluate the effect of polymer-coated urea on the control of ammonia volatilization, yield and nutritional characteristics of maize. The experiment was carried out during one maize growing cycle in 2009/10 on a Geric Ferralsol, inUberlândia, MG, Brazil. Nitrogen fertilizers were applied as topdressing on the soil surface in the following urea treatments: polymer-coated urea at rates of 45, 67.5 and 90 kg ha-1 N and one control treatment (no N), in randomized blocks with four replications. Nitrogen application had a favorable effect on N concentrations in leaves and grains, Soil Plant Analysis Development (SPAD) chlorophyll meter readings and on grain yield, where as coated urea had no effect on the volatilization rates, SPAD readings and N leaf and grain concentration, nor on grain yield in comparison to conventional fertilization.


HortScience ◽  
2004 ◽  
Vol 39 (7) ◽  
pp. 1745-1749 ◽  
Author(s):  
Eric D. Miltner ◽  
Gwen K. Stahnke ◽  
William J. Johnston ◽  
Charles T. Golob

Late fall N fertilization of cool-season turfgrass in northern climates is a common practice. Previous research has been focused in climates where freezing temperatures prevail. Research in more moderate northern climates where turf may not go through winter dormancy is scarce. Four fertilizer N sources and an untreated control were applied in four different months (November, December, January, or February) to perennial ryegrass (Lolium perenne L.) in Puyallup, Wash., and to kentucky bluegrass (Poa pratensis L.) In Pullman, Wash., to compare their effects in moderate (Puyallup) and freezing (Pullman) winter climates. In Pullman, only November applications of ammonium sulfate (AmS) or polymer coated sulfur coated urea (PCSCU) enhanced winter turfgrass quality. In Puyallup, November or December application of AmS, PCSCU, or polymer coated urea (PCU) resulted in enhanced winter quality. Polymer coated urea yielded a delayed initial response and a longer residual effect in the spring. Isobutylidenediurea (IBDU) did not improve winter turf quality in either Pullman or Puyallup. Although there was no quality response following January fertilizer application, there was suppression of red thread [Laetisaria fuciformis (McAlpine) Burds.] symptoms in Puyallup, indicating N uptake. Late fall fertilizer N in eastern Washington should be confined to November, using soluble or more quickly available slow-release nitrogen fertilizers. The application window can be extended to December in western Washington, and more slowly available coated ureas can be effectively used.


2020 ◽  
Vol 100 (1) ◽  
pp. 44-57 ◽  
Author(s):  
Chedzer-Clarc Clément ◽  
Athyna N. Cambouris ◽  
Noura Ziadi ◽  
Bernie J. Zebarth ◽  
Antoine Karam

Residual soil NO3-N (RSN) is susceptible to loss during the non-growing season. This 5 yr study investigated the effects of three N fertilizer sources [ammonium nitrate (AN), ammonium sulfate (AS), and polymer-coated urea (PCU)] applied at four rates (60, 120, 200, and 280 kg N ha−1) plus an unfertilized control on RSN following potato production and on overwinter NO3-N changes in an irrigated sandy soil in Quebec, Canada. Composite soil samples were collected at the 0–15, 15–30, 30–60, and 60–90 cm depths immediately after potato harvest in fall and again in the following spring from 2008 to 2012. Residual soil NO3-N content within the 0–30 cm depth (RSN0–30) was highly correlated with the RSN content in the 0–90 cm depth (RSN0–90), indicating that RSN0–30 can be used as an indicator of soil profile NO3-N accumulation. Overall, RSN0–90 increased with fertilizer N application rate, particularly for above the minimum fertilizer N rate required to maximize yield (Nmax), and was generally higher for years with greater pre-plant soil NO3-N. The split application of AN and AS resulted in lower RSN0–90 than the single application of PCU at above Nmax. Overwinter losses of soil NO3-N were generally increased with increasing RSN0–90 in fall. The results suggest that reducing the fertilizer N rate is more important than the choice of N source in managing RSN.


2009 ◽  
Vol 33 (6) ◽  
pp. 1685-1694 ◽  
Author(s):  
Hamilton Seron Pereira ◽  
Anabelisa Ferreira Leão ◽  
Adriana Verginassi ◽  
Marco Aurélio Carbone Carneiro

The aim of this study was to evaluate the N losses due to volatilization at different rates of common urea, polymer coated urea and urease inhibitor-treated urea in the out-of-season corn, using semi-open static collectors. The treatments consisted of N levels on side-dressing fertilization with urea in different treatments: (a) control (without N), (b) urea 40 kg ha-1 N, (c) urea 80 kg ha-1 N, (d) polymer coated urea 40 kg ha-1 N, (e) polymer coated urea 80 kg ha-1 N and (f) urea with the urease inhibitor (UI) N 80 kg ha-1 N. The results showed that the treatments with polymer coated urea and with urease inhibitor-treated urea reduced the volatilization of N around 50 % compared to common urea, either in the first and the second N side-dressing fertilizations. Thus, they demonstrate that the polymer coat and the urease inhibitors were effective in reducing the volatilization of urea N applied in coverage, which resulted in higher productivity. There was also increasing urease activity in the treatments with application of common urea.


HortScience ◽  
1999 ◽  
Vol 34 (3) ◽  
pp. 523B-523
Author(s):  
Francis Zvomuya ◽  
Carl J. Rosen

Polyolefin-coated fertilizers are slow-release fertilizers coated with thermoplastic resins that have a temperature-dependent nutrient release pattern. A field study was conducted on a Hubbard loamy sand during 1997 and 1998 at Becker, Minn., to evaluate the effect of polyolefin-coated urea (POCU) fertilizers (Meister, Chisso Co., Japan) on yield and quality of irrigated `Russet Burbank' potatoes (Solanum tuberosum L.). The coated fertilizers were POCU-50 and POCU-70, which release 80% of their N in 50 and 70 days, respectively, at 25 °C, and a 1 POCU-50: 1POCU-70 mixture. The study compared three soluble urea treatments (N at 0, 140, and 280 kg·ha-1) split-applied at planting, emergence, and hilling vs. the same N rates of coated urea fertilizers applied in a band at planting. In 1997, a season characterized by high leaching, total and large tuber (>168 g) yields were higher with coated urea sources than soluble urea at equivalent N rate, but the N sources gave similar yields in 1998 when leaching was minimal. In both years, doubling the rate of N as soluble or coated urea from 140 to 280 kg·ha-1 had no effect on total yield, but increased the marketable yield (tuber size). Yields were higher in 1998 compared to 1997 due to poorer tuber set in 1997. However, the percentage of large tubers was higher in 1997. Specific gravity increased slightly with N rate but did not differ with N source at equivalent N rate. Hollow heart incidence was similar among all treatments in 1997, but it increased with N rate and was similar among N sources in 1998.


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