scholarly journals Nitrogen fertilizer use efficiency, recovery and leaching of an alexandergrass pasture

2011 ◽  
Vol 35 (3) ◽  
pp. 899-906 ◽  
Author(s):  
Laércio Ricardo Sartor ◽  
Tangriani Simioni Assmann ◽  
André Brugnara Soares ◽  
Paulo Fernando Adami ◽  
Alceu Luiz Assmann ◽  
...  

Nitrogen usually determines the productive potential of forage crops, although it is highly unstable in the environment. Studies on recovery rates and use efficiency are important for more reliable fertilizer recommendations to reduce costs and avoid environmental pollution. The purpose of this study was to evaluate N use efficiency and recovery rate of Alexandergrass pasture (Brachiaria - Syn. Urochloa plantaginea) as well as N-NO3- and N-NH4+ soil concentrations using different levels of N fertilization under two grazing intensities. The experiment was arranged in a randomized block design in a factorial scheme with three replications. Treatments consisted of three N rates (0, 200 and 400 kg ha-1 N) and two grazing intensities termed low mass (LM; forage mass of 2,000 kg ha-1 of DM) and high mass (HM; forage mass of 3,600 kg ha-1 of DM) under continuous stocking and variable stocking rates. Results of N fertilization with 200 kg ha-1 were better than with 400 kg ha-1 N. There was a significant effect of N rates on soil N-NO3-concentration with higher levels in the first layer of the soil profile in the treatment with 400 kg ha-1 N. Grazing intensity also affected soil N-NO3- concentration, by increasing the levels under the higher stocking rate (lower forage mass).

2012 ◽  
Vol 36 (2) ◽  
pp. 475-483 ◽  
Author(s):  
José Hildernando Bezerra Barreto ◽  
Ismail Soares ◽  
José Almeida Pereira ◽  
Antonio Marcos Esmeraldo Bezerra ◽  
José Aridiano Lima de Deus

Nitrogen is the most important nutrient for rice (Oryza sativa L) yields. This study aimed to evaluate the response of upland rice cultivars to N rate and application times in a randomized block design, in subdivided plots with four replications. The studied factors were five rice cultivars (BRS MG Curinga, BRS Monarca, BRS Pepita, BRS Primavera, and BRS Sertaneja), three application times (100 % at planting, 50 % at planting - 50 % at tillering and 100 % at tillering) and four N rates (0, 50, 100, and 150 kg ha-1). All cultivars responded to increased rates and different times of N application, especially BRS Primavera and BRS Sertaneja, which were the most productive when 50 % N rates were applied at sowing and 50 % at tillering. The response of cultivar BRS Monarca to N fertilization was best when 100 % of the fertilizer was applied at tillering.


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.


Revista CERES ◽  
2016 ◽  
Vol 63 (3) ◽  
pp. 387-393
Author(s):  
Elisângela Dupas ◽  
Salatiér Buzetti ◽  
Flávio Henrique Silveira Rabêlo ◽  
André Luís Sarto

ABSTRACT Nitrogen (N) is the most limiting nutrient for growth of forage grasses, especially in conditions of low water availability. Therefore, it is important to evaluate the effect of N fertilization and irrigation on the accumulation of carbon (C) and carbon dioxide (CO2) by marandu grass in the Cerrado Paulista, in the rainy and dry seasons. Experiments were conducted to evaluate N fertilization in each season, with and without irrigation. Five N rates were used (0, 50, 100, 150 and 200 kg ha-1 per cutting), using urea as N source, totaling 0, 300, 600, 900 and 1200 kg ha-1 in the rainy season and 0, 100, 200, 300 and 400 kg ha-1 in the dry season. The experiments were arranged in a split-plot randomized block design. There was no significant interaction (p > 0.05) between N and time of fertilization in the irrigated experiment. However, N promoted a quadratic effect in organic matter production (OMP), accumulation of C and CO2 by marandu grass, while there was no influence of the seasons. In the non-irrigated experiment, the interaction between N rates and seasons was significant (p < 0.05) only for the rainy season. Organic matter production and C and CO2 accumulation was greater in the rainy season than in the dry season. Irrigation provided increases of approximately 20% in C and CO2 accumulation. The use of N and irrigation increases the accumulation of C and CO2 by marandu grass, and this increase is higher during the rainy season.


Revista CERES ◽  
2013 ◽  
Vol 60 (6) ◽  
pp. 852-862
Author(s):  
Maria do Carmo Lana ◽  
Rodrigo Vianei Czycza ◽  
Jean Sérgio Rosset ◽  
Jucenei Fernando Frandoloso

The objective of this study was to evaluate split nitrogen (N) fertilization of maize applied in band at sowing and top dressing with and without crop rotation, under no-till. The experiment was conducted with six N rates at sowing (0, 20, 30, 40, 50 and 60 kg ha-1) combined with three rates in top dressing (40, 70, 100 kg ha-1) and two management systems: after five cropping sequences of maize and crop rotation (maize + soybean + oat + soybean + corn) in a randomized block design with four replications. The crop rotation system increased yield in approximately 7% in relation to the area without rotation. The split of nitrogen fertilization, in rates above 39 and 54 kg ha-1 at sowing and 70 and 40 kg ha-1 in top dressing, resulted in yield higher than that obtained with the application of 100 kg ha-1 in top dressing. Grain yield was higher with the rates 50 and 70 kg ha-1 of N compared with that obtained with 20 and 100 kg ha-1 at sowing and top dressing, respectively. The rate 70 kg ha-1 of N resulted in the highest yield at the lowest cost compared with the revenues and costs incurred with the rates 40 and 100 kg ha-1.


2020 ◽  
Vol 11 (4) ◽  
Author(s):  
César Ferreira Santos ◽  
Sheila Isabel do Carmo Pinto ◽  
Konrad Passos e Silva ◽  
Paulino Da Cunha Leite ◽  
Vagner Aparecido Vitor

Controlled-release fertilizers are possible strategies to reduce losses through fertilization and increase nitrogen (N) use efficiency. In this context, this study aimed to evaluate the efficiency of N sources applied to second-crop corn cultivation. The experiment was carried out in a randomized block design in a 2 x 4 factorial scheme. Two cultivation systems (conventional and no-tillage) and four N fertilizers (urea pearls pure, urea+Cu+B, NBPT-treated urea and complex mineral fertilizer) with four replications were studied. Losses of N-NH3 by volatilization were evaluated up to 14 days after corn N fertilization. The data were subjected to analysis of variance and the means were grouped by the Scott-Knott test at 5% probability. Under the conditions in which the study was carried out, it was observed that urea pearls pure was the least efficient N fertilizer in restricting N-NH3 through volatilization losses. The most efficient fertilizer was NBPT-treated urea. Losses of N-NH3 by volatilization in the no-tillage system were higher than in the conventional cultivation system.


2016 ◽  
Vol 37 (4Supl1) ◽  
pp. 2487
Author(s):  
Giselle Abadia Campos Pereira ◽  
Leni Rodrigues Lima ◽  
Joelson Antônio Silva ◽  
Rosemay Lais Galati ◽  
Joanis Tilemahos Zervoudakis ◽  
...  

The study was carried out in a greenhouse with a 4X4 factorial arrangement randomized block design in order to evaluate the effects of nitrogen rates (0, 50, 100 and 150 mg dm-3) associated with cutting heights (10, 15, 20 and 25 cm) on dry matter production and the chemical composition of Massai grass. The seeding was done in pots with 11 kg of soil. 10 plants were kept per pot, and there were two cuts every 35 days. Nitrogen fertilization was split between the two cuts, where the first N application occurred after the uniformity cut and the second after the first cut. In each cut the plants were separated and weighed for botanical component evaluation: leaf blade and stem + sheath. After this, the samples were homogenized and analysed for dry matter (DM), crude protein (CP) and neutral detergent fibre (NDF) content. In the first cut, the N fertilization caused a linear increase in DM production of 0.058 g pot-1 per each 1 mg dm-3 of N applied, as well as causing an increase of 0.549% in CP percentage, a 0.0124 pot-1 g increase in CP production and a reduction of 0.055% in NDF. In the second cut, N rates promoted a quadratic effect on DM production. A maximum DM production of 16.48 g pot-1 with 107.27 mg dm-3 of N was observed while CP production content was increased by 0.0092 g pot-1 for each 1 mg dm-3 N applied. In terms of linear responses to DM and PB, as well as the use efficiency calculated for Massai grass, recommended N doses range between 50 and 100 g dm-3.


2021 ◽  
Vol 42 (4) ◽  
pp. 2539-2554
Author(s):  
Felipe Luiz Chiamulera Deifeld ◽  
◽  
André Brugnara Soares ◽  
Daniel Schmitt ◽  
Tangriani Simioni Assmann ◽  
...  

This study was developed to examine the effect of combining nitrogen (N) fertilization strategies and pasture management heights on animal and grain production in an Integrated Crop-Livestock System. The experiment was carried out in the municipality of Abelardo Luz - SC, Brazil, between April 2017 and April 2018. A randomized-block design was adopted, with the treatments arranged in a 2×2 factorial arrangement with three replicates. The first factor was the height of the pasture managed under continuous grazing: high (HH, 20 cm) or low (LH, 12 cm). The second factor corresponded to the N application times: in the winter, in the pasture (NP), and in the summer, in the grain crop (NG), in a single N rate of 200 kg ha-1 as topdressing. The forage species used during the pasture phase was black oat (Avena strigosa Schreb), and the pasture was grazed by Nellore × Charolais crossbred steers with an initial body weight of 260 kg. The summer crop was maize (Zea mays). Average daily gain (ADG) and herbage allowance were higher in HH than in LH, whereas animal load was higher in HH. Between the N application times, the animal load was higher in NP. Pasture management height and N fertilization strategy did not affect the variables of number of rows per ear, number of grains per row, thousand-grain weight, or total grain yield, which overall averaged 14,090 kg ha-1. In conclusion, the inversion of nitrogen fertilization between the periods of winter pasture production and grain crop and the management height of the black oat pasture do not compromise the production of maize grains in the summer, or animal production per area. However, steer performance is greater (higher ADG) when the pasture is managed at 20 cm, whereas a high grazing intensity significantly reduces straw on the soil.


2020 ◽  
Vol 12 (9) ◽  
pp. 3621
Author(s):  
Ruth-Maria Hausherr Lüder ◽  
Ruijun Qin ◽  
Walter Richner ◽  
Peter Stamp ◽  
Bernhard Streit ◽  
...  

Limited information exists on how tillage and nitrogen (N) fertilization affects small-scale variation in nitrogen use efficiency (NUE) and crop performance. In a two-year field study under temperate conditions, we investigated how tillage (NT, no-tillage; CT, conventional tillage) and N fertilization affected the small-scale variation in NUE and winter wheat performance (grain yield, Gw; grain protein concentration, GPC). A randomized complete block design with three replications was used. Within each tillage plot (12 × 35 m2), N rates (0, 50, 100, 150, 200, 250 kg N ha−1) were completely randomized within each of four groups of microplots (1.5 × 1.5 m2). Early-season soil mineral N (Nmin) was also monitored in both years. At rates < 150 kg N ha−1, NT was not competitive with CT in terms of Gw and NUE. Gw and aboveground plant N were not correlated with Nmin prior to application of N fertilizer. NT usually led to larger spatial heterogeneity of Nmin, Gw, and NUE. The small-scale variability of Gw, GPC, NUE, and N supply decreased with increasing N fertilization rates under both tillage systems. Significant increases in Gw and GPC were observed with increasing N rates, whereas NUE decreased slightly with increasing N rates in both NT and CT. The overall moderate spatial variation in Nmin, Gw, and NUE did not justify site-specific N fertilization in these small fields, with the exception of the stony within-plot positions, which were not responsive to rates of N > 50 kg N ha−1.


2009 ◽  
Vol 33 (5) ◽  
pp. 1303-1310 ◽  
Author(s):  
Marcelo Carvalho Minhoto Teixeira Filho ◽  
Salatiér Buzetti ◽  
Marcelo Andreotti ◽  
Marco Eustáquio de Sá ◽  
Orivaldo Arf ◽  
...  

High wheat yields require good N fertilization management. The objective of this study was to evaluate the effects of different N applications at sowing using Entec (N source with nitrification inhibitor) and urea (traditional N source) at covering, on four wheat cultivars. The experiment was conducted in a randomized block design in a factorial scheme, with four replications, at the Experimental Station of the Faculdade de Engenharia de Ilha Solteira - UNESP, on a dystrophic, epi-eutrophic alic Red Latosol with loamy texture, formerly under savannah vegetation. Four N rates (0, 60, 120, and 180 kg ha-1) were tested, applied at sowing in the case of Entec and top-dressed 40 days after plant emergence in the case of urea, and the four wheat cultivars E 21, E 22, E 42, and IAC 370. The yield of the wheat cultivars E 21 and E 42 was highest. Plant height and lodging index of cultivar E 22 were greatest, with consequently lowest grain yield. There was no significant difference between Entec (applied at sowing) and urea (top-dressed) in terms of grain yield and yield components. Nevertheless, urea resulted in a higher N leaf content, and Entec in a larger number of undeveloped spikelets. High nitrogen rates influenced the hectoliter mass negatively, affecting wheat grain quality. Grain yield increased under N rates of up to 82 kg ha-1 N, through Entec applied at sowing or top-dressed urea.


Revista CERES ◽  
2017 ◽  
Vol 64 (4) ◽  
pp. 351-359
Author(s):  
Telmo Jorge Carneiro Amado ◽  
Enrique Oswin Hahn Villalba ◽  
Rafael Pivotto Bortolotto ◽  
Douglas Dalla Nora ◽  
Jardes Bragagnolo ◽  
...  

ABSTRACT Despite its relevance, nitrogen is poorly utilized by the plants when improperly applied. Thus, the objective of this study was to evaluate the yield and nitrogen use efficiency (NUE) in corn in response to doses and split application of nitrogen fertilization. The experimental design was a randomized block design, with three replications. Doses of nitrogen of 0, 30, 60 and 180 kg ha-1 were applied at sowing in order to create different nutritional status of corn plants and to obtain different values of Normalized Difference Vegetation Index (NDVI) measured with “Greenseeker®” optical sensor. The subplots with nitrogen doses in topdressing of 0, 30, 60 and 90 kg ha-1 at V8 and a dose of 60 kg ha-1 at V12 were placed in experimental plots with doses of 0, 30, 60 and 180 kg ha-1 of nitrogen at sowing. Moreover, NUE was calculated in the experiment using agronomic indexes determined by applications of nitrogen in late topdressing (V8 and V12) and contrasted to the possible combinations at doses of 60, 90 and 120 kg ha-1 of total N applied. The results showed the occurrence of a linear relationship between nitrogen fertilizer dose and NDVI at V8 as well as at V12 stages. Late topdressing fertilizations (V12) did not cause a decrease in grain yield when combined with nitrogen fertilization at sowing, moreover resulted in higher NUE. Split the nitrogen dose showed better NUE than the combinations where nitrogen was not applied at sowing or in topdressing. The delay of nitrogen topdressing can be an alternative for the planning of the moment of the N fertilization according to the climate forecast in each region.


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