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Nitrogen-use efficiency and economic efficiency of slow-release N fertilisers applied to irrigated turfs in a Mediterranean environment

Arrobas, Margarida; Parada, Maria; Magalhães, Paula; Rodrigues, M.A.
Fonte: Instituto Politécnico de Bragança Publicador: Instituto Politécnico de Bragança
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
75.95%
The effect of three fertilisers that delay the bioavailability of nitrogen (N) in the soil was compared with ammonium nitrate and a zero N control in two irrigated turfs in NE Portugal. The fertilisers used were: Floranid permanent 16-7-15 (slow-release, IBDU/Isodur fertiliser); Basacote plus 9M 16-8-12 (controlled-release fertiliser, copolymer ethylene acrylic); Nitroteck 20-8-10 (stabilized fertiliser, dicyandiamide as nitrification inhibitor + coating with polyterpene) and Nitrolusal (ammonium nitrate, 20.5% N), applied all at a rate of 120 kg N ha-1. Nitrolusal was split into two fractions of 60 kg N ha-1. Phosphorus (P) and potassium (K) rates were balanced among treatments by using superphosphate (18% P2O5) and potassium chloride (60% K2O). The turf dry matter (DM) yield and N concentration in dry material were determined from several cuts of biomass throughout the growing season. Based on DM yield, N concentration in dry material and fertilisation costs, indices of N use efficiency and economic efficiency were estimated. Soil nitrate levels were monitored by using anion exchange membranes inserted directly into the soil. Basacote gave significantly lower DM yields than the other fertilised treatments. The apparent N recovery of Basacote was also the lowest. The results showed that Basacote released less N than that required for an adequate plant growth in the beginning of the growing season...

Dinâmica do nitrogênio na cultura do milho (Zea mays L.), em cultivo sucessivo com aveia preta (Avena strigosa), sob implantação do sistema plantio direto; Nitrogen dynamics in maize (Zea Mays L) and black oats (Avena srigosa) successive cropping under the introduction of the no-tillage system

Fernandes, Flavia Carvalho Silva
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 21/02/2006 PT
Relevância na Pesquisa
76.06%
O presente trabalho foi desenvolvido na área experimental da ESALQ-USP, localizada no município de Piracicaba/SP, em um Latossolo Vermelho Amarelo, textura areno-argiloso. O experimento teve como objetivo estudar a dinâmica do N no sistema solo-planta da cultura do milho, sob implantação do sistema plantio direto, e, pela técnica do 15N, avaliar a lixiviação de nitrato à profundidade de 0,80 m, a eficiência de utilização do N e o efeito residual do fertilizante nas culturas subseqüentes. O projeto envolveu dois cultivos de milho e um de aveia preta, cultivada na entressafra. O delineamento experimental foi o de blocos casualizados (3x2), com 4 repetições. Os tratamentos consistiram de doses de nitrogênio, na forma de sulfato de amônio (60, 120 e 180 kg ha-1 de N) e uma testemunha, além dos parcelamentos (30 kg ha-1 de N na semeadura e o restante em cobertura; 60 kg ha-1 de N na semeadura e o restante em cobertura). A aplicação de sulfato de amônio enriquecido com 15N foi feita, na dose de 120 kg ha-1 de N, em subparcelas, previamente definidas, apenas no primeiro cultivo do milho. Foram feitas as seguintes avaliações: densidade de fluxo de água e de nitrato na profundidade de 0,80 m do solo (dose de 120 kg ha-1 de N); massa de 100 grãos; massa de matéria seca; teor de N; rendimento de grãos de milho; átomos % 15N nas plantas e solo; fração do N fertilizante na solução do solo na profundidade de 0...

Avaliação do inibidor de nitrificação fosfato de 3,4-dimetilpirazol (DMPP) em três solos com gradiente textural, absorção e uso de nitrogênio em plantas de algodão; Evaluation of nitrification inhibitor 3,4-dimethylpyrazol phosphate (DMPP) in three soils as related to textural gradient, nitrogen uptake and N-use efficiency by cotton plants

Paulo, Ezio Nalin de
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 27/09/2012 PT
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86.17%
A utilização de inibidores de nitrificação pode ser uma alternativa interessante para aumentar a eficiência do uso do fertilizante nitrogenado em diversas culturas, porém, essa alternativa vem sendo pouco estudada em condições de solo e clima do Brasil. Assim, objetivou-se com esse trabalho avaliar a eficiência do inibidor de nitrificação fosfato de 3,4-dimetilpirazol (DMPP) em três solos com gradiente textural, bem como avaliar o destino do nitrogênio (N-NO3-, N-NH4+ e 15N) no solo, a absorção e o uso do nitrogênio (N-total e 15N) nas plantas de algodão. Três experimentos foram montados e desenvolvidos. No primeiro foi efetuada a incubação do solo em condições de laboratório para avaliar a inibição da nitrificação pelo DMPP aplicado na forma de ureia e sulfonitrato de amônio (SNA) em três solos (Neossolo Quartzarênico - NQ, Latossolo Vermelho Amarelo - LVA, Latossolo Vermelho - LV). No segundo experimento plantas de algodão foram cultivadas em colunas de lixiviação com os mesmos solos, recebendo ureia e sulfonitrato de amônio, com e sem DMPP como fonte de N. Foram avaliados a produção de matéria seca, o acúmulo de nutrientes nas plantas, a eficiência de uso do N pelo algodoeiro, a lixiviação e a quantidade de N mineral no solo após o cultivo do algodão por 60 dias. No terceiro experimento...

Fertilização nitrogenada no consórcio milho - braquiária em solos de clima tropical úmido no sistema de integração lavoura-pecuária; Nitrogen fertilization in intercropping corn and palisadegrass at weathered soils in crop-livestock integration system

Almeida, Rodrigo Estevam Munhoz de
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 18/02/2014 PT
Relevância na Pesquisa
76.07%
O sistema integração lavoura pecuária (ILP) atende muitas diretrizes para estabelecer um manejo sustentável de produção agropecuária. Consiste em integrar na mesma área, a produção agrícola e pecuária de forma que haja o cultivo de grãos e estabeleça uma pastagem para a criação de animais. O consórcio de milho com braquiária é uma tecnologia utilizada para se atingir os objetivos da ILP. Trata-se de técnica de cultivo de milho junto com a braquiária sem prejuízo ao milho, e que a braquiária possa se estabelecer na área após a colheita do milho. A eficiência da adubação nitrogenada (EAN) na cultura do milho é discutida na literatura em trabalhos que utilizaram fertilizantes marcados com 15N. Os dados são variados pelo motivo do nitrogênio ter dinâmica complexa no sistema produtivo. Trabalhos que avaliaram a EAN no consórcio de milho com braquiária são escassos na literatura internacional, e não se sabe quanto do fertilizante nitrogenado aplicado é absorvido pela planta forrageira, e se é necessário um aumento da dose para não ocorrer falta de nitrogênio neste sistema de produção. Esta tese foi realizada com os seguintes objetivos (i) avaliar a influência da braquiária no aproveitamento do fertilizante nitrogenado...

Characterization of brazilian wheat cultivars in terms of nitrogen use efficiency

Silva,Cristiano Lemes da; Benin,Giovani; Bornhofen,Elesandro; Todeschini,Matheus Henrique; Dallo,Samuel Cristian; Sassi,Luiz Henrique Scarparo
Fonte: Instituto Agronômico de Campinas Publicador: Instituto Agronômico de Campinas
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/06/2014 EN
Relevância na Pesquisa
76.07%
Nitrogen (N) management in wheat crop is one of the most studied agricultural practices in Brazil; however, there are few reports on its use efficiency. The objective of this study was to characterize 18 Brazilian wheat cultivars, which are representative and have been recently released to cultivation, for nitrogen use efficiency (NUE). The experiments were carried out in Pato Branco, Paraná, and Coxilha, Rio Grande do Sul, during the 2011 crop season. It was used a randomized block design with three replications, in factorial scheme (2 environments × 18 cultivars). Genetic variability was observed for nitrogen utilization efficiency by grains (NUtEg=47.6 to 81.1 kg kg-1) and nitrogen harvest index (NHI=71.3 to 84.6%) with significant effects relating to the environment of cultivation and performance of these traits. The evaluation of the protein concentration of grain by near infrared spectrometry (GPC N) produced equivalent results to the direct analytical method of Kjeldahl (GPC K), in Pato Branco (r=0.56) and Coxilha (RS) (r=0.80). However the CPG N overestimated the protein values by 16.85%. The GPC and protein yield were positively correlated with NUtEg and NHI. The best performance for the traits associated with NUE was observed for the following cultivars: Mirante...

Urea and sugarcane straw nitrogen balance in a soil-sugarcane crop system

Gava,Glauber José de Castro; Trivelin,Paulo Cesar Ocheuze; Vitti,André Cesar; Oliveira,Mauro Wagner de
Fonte: Embrapa Informação Tecnológica; Pesquisa Agropecuária Brasileira Publicador: Embrapa Informação Tecnológica; Pesquisa Agropecuária Brasileira
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/07/2005 EN
Relevância na Pesquisa
75.92%
The objectives of this study were to evaluate nitrogen utilization by sugarcane ratoon from two sources, applied urea and sugarcane straw covering soil surface (trash blanket), besides the recovery of N from both sources in the soil-plant system. The following treatments were established in a randomized block design with four replicates: T1, vinasse-urea (100 kg ha-1 of urea-N) mixture applied on the total area of the soil covered with cane trash labeled with 15N; T2, vinasse-urea mixture (urea labeled with 15N; 100 kg ha-1 of urea-N) applied on the total area of the soil covered with non-labeled sugarcane trash; and T3, urea-15N (100 kg ha-1 of urea-N) applied in furrows at both sides of cane rows, with previous surface application of vinasse, onto soil without trash covering. The vinasse was applied at a rate of 100 m³ ha-1 in all treatments. The experiment was carried out on a Yellow Red Podzolic soil (Paleudalf), from October 1997 to August 1998, in Piracicaba, SP, Brazil. The nitrogen use efficiency of urea by the sugarcane ratoon was 21%, while that of the sugarcane straw was 9%. The main contributions of N from sugarcane trash, during one cycle, are the preservation and increase of the organic N in soil. The tendency for a lower accumulation of urea-N in the sugarcane plant...

Nitrogen availability, leaf life span and nitrogen conservation mechanisms in leaves of tropical trees

Corte,Guilherme Nascimento; Macchiaverni,Patrícia; Fabbro,Inácio Maria Dal; Haddad,Claudia Regina Baptista
Fonte: São Paulo - Escola Superior de Agricultura "Luiz de Queiroz" Publicador: São Paulo - Escola Superior de Agricultura "Luiz de Queiroz"
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/12/2009 EN
Relevância na Pesquisa
76.08%
Evergreen species of temperate regions are dominant in low-nutrient soils. This feature is attributed to more efficient mechanisms of nutrient economy. Nevertheless, the cashew (Anacardium occidentale- Anacardiaceae), a deciduous species, is native to regions in Brazil with sandy soil, whilst the annatto (Bixa orellana- Bixaceae), classified as an evergreen species native to tropical America, grows spontaneously in regions with more humid soils. Evergreens contain robust leaves that can resist adverse conditions for longer. The physical aspects of the leaves and mechanisms of nutrient economy between the two species were compared, in order to verify whether the deciduous species had more efficient mechanisms that might explain its occurrence in regions of low soil fertility. The mechanisms of nitrogen economy were also compared for the two species at available concentrations of this nutrient. The following were analysed: (i) leaf life span, (ii) physical leaf characteristics (leaf mass per area, and rupture strain), (iii) nitrogenous compounds (nitrogen, chlorophyll, and protein), (iv) nitrogen conservation mechanisms (nitrogen resorption efficiency, resorption proficiency, and use efficiency), and (v) nitrogen conservation mechanisms under different availability of this mineral. The higher values of leaf mass per area and leaf rupture strain found in A. occidentale were related to its longer leaf life span. A. occidentale showed lower concentrations of nitrogen and protein in the leaves than B. orellana. Under lower nitrogen availability...

Yield, chemical composition, and efficiency of use of nitrogen by Marandu grass

Oliveira,Tadeu Silva de; Leonel,Fernando de Paula; Pereira,José Carlos; Silva,Cássio José da; Baffa,Danielle Ferreira; Zervoudakis,Joanis Tilemahos
Fonte: Sociedade Brasileira de Zootecnia Publicador: Sociedade Brasileira de Zootecnia
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2014 EN
Relevância na Pesquisa
76.14%
The objective of this study was to evaluate the effect of five nitrogen doses on the productive and quality characteristics and the use efficiency of Brachiaria brizantha cv. Marandu grass. The treatments consisted of four doses of nitrogen (0, 60, 120, 180 and 240 kg ha-1), distributed through a completely randomized design with four replicates. Samples of the material were collected to analyze productivity variables, concentrations of neutral detergent fiber, crude protein and neutral detergent insoluble nitrogen, and in vitro dry matter digestibility. The nitrogen use efficiency, recovery of the applied nitrogen (RAN) and agronomic efficiency of the applied nitrogen (AE) were calculated. Dry mass production increased by 1,624.67 (kg/ha) as the nitrogen doses were increased. The doses of nitrogen affected the concentrations of neutral detergent fiber (from 294.6 to 381.4 g.kg-1, in the leaf), crude protein (from 86.1 to 99.6 g.kg-1, in the leaf) and neutral detergent insoluble protein (from 402.9 to 396.2 g.kg-1 CP, in the leaf). Nitrogen use efficiency increased, whereas RAN and AE were not affected by the nitrogen doses. Nitrogen fertilization promotes improvement in productivity and chemical composition of Marandu grass, also improving the efficiency with which the grass utilizes the nitrogen.

Implications of selection in common bean lines in contrasting environments concerning nitrogen levels

Furtini,Isabela Volpi; Ramalho,Magno Antonio Patto; Abreu,Ângela de Fátima Barbosa
Fonte: Crop Breeding and Applied Biotechnology Publicador: Crop Breeding and Applied Biotechnology
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/10/2014 EN
Relevância na Pesquisa
75.96%
Grain productivities of 100 bean lines were evaluated in the presence and absence of nitrogen fertilizer in order to identify those with high nitrogen use efficiency (NUE) and to determine the correlated response observed in a stressed environment following selection in a non-stressed environment. The genetic and phenotypic characteristics of the lines, as wellas the response index to applied nitrogen, were determined. The average grain productivities at both locations were 39.5% higher in the presence of nitrogen fertilizer, with 8.3 kg of grain being produced per kg of nitrogen applied. NUE varied greatly between lines. Lines BP-16, CVII-85-11, BP-24, Ouro Negro and MA-IV-15-203 were the most efficient and responsive. The results showed that it is possible to select bean lines in stressed and non-stressed environments. It was inferred that common bean lines for environments with low nitrogenav ailability should preferably be selected under nitrogen stress.

Nitrogen-use efficiency of maize genotypes in contrasting environments.

MARTINS, A. O.; CAMPOSTRINI, E.; MAGALHAES, P. C.; GUIMARAES, L. J. M.; DURAES, F. O. M.; MARRIEL, I. E.; NETTO, A. T.
Fonte: Crop Breeding and Applied Biotechnology, Londrina, v. 8, n. 4, p. 291-298, 2008. Publicador: Crop Breeding and Applied Biotechnology, Londrina, v. 8, n. 4, p. 291-298, 2008.
Tipo: Artigo em periódico indexado (ALICE)
EN
Relevância na Pesquisa
76.03%
The purpose ofthis study was to evaluate the nitrogen-use efficiency of 15 corn hybrids in different environments. The experiment was conducted at the research station Embrapa Milho e Sorgo, in environments with low (12 kg ha-l) and high (120 kg ha-J) nitrogen fertilization, in a randomized block design with three replications. The chlorophyll content, leaf nitrogen and nitrate reductase activity in the flag leaf were determined at flowering and the grain yield was evaluated at harvest. The chlorophyll content proved to be sensitive to nitrogen availability, although without discriminating genotypic differences efficiently. To use nitrate reductasefor this purposeJurther studies are needed on the reliability ofthis biochemical variable to diagnose genotypes efficient in N use precociously. The hybrid L2xL3 was considered promising for maize breeding programs aimed at gene introgression related to N-use efficiency.; 2008

Urea and sugarcane straw nitrogen balance in a soil-sugarcane crop system.

GAVA, G.J. de C.; TRIVELIN, P.C.O.; VITTI, A.C.; OLIVEIRA, M.W. de
Fonte: Pesquisa Agropecuária Brasileira, Brasília, v.40, n. 7, p. 689-695, jul. 2005. Publicador: Pesquisa Agropecuária Brasileira, Brasília, v.40, n. 7, p. 689-695, jul. 2005.
Tipo: Artigo em periódico indexado (ALICE)
EN
Relevância na Pesquisa
75.92%
The objectives of this study were to evaluate nitrogen utilization by sugarcane ratoon from two sources, applied urea and sugarcane straw covering soil surface (trash blanket), besides the recovery of N from both sources in the soil-plant system. The following treatments were established in a randomized block design with four replicates: T1, vinasse-urea (100 kg ha-1 of urea-N) mixture applied on the total area of the soil covered with cane trash labeled with 15N; T2, vinasse-urea mixture (urea labeled with 15N; 100 kg ha-1 of urea-N) applied on the total area of the soil covered with non-labeled sugarcane trash; and T3, urea-15N (100 kg ha-1 of urea-N) applied in furrows at both sides of cane rows, with previous surface application of vinasse, onto soil without trash covering. The vinasse was applied at a rate of 100 m3 ha-1 in all treatments. The experiment was carried out on a Yellow Red Podzolic soil (Paleudalf), from October 1997 to August 1998, in Piracicaba, SP, Brazil. The nitrogen use efficiency of urea by the sugarcane ratoon was 21%, while that of the sugarcane straw was 9%. The main contributions of N from sugarcane trash, during one cycle, are the preservation and increase of the organic N in soil. The tendency for a lower accumulation of urea-N in the sugarcane plant...

Inheritance of nitrogen use efficiency in inbred progenies of tropical maize based on multivariate diallel analysis.

GUEDES, F. L.; DINIZ, R. P.; BALESTRE, M.; RIBEIRO, C. B.; CAMARGOS, R. B.; SOUZA, J. C.
Fonte: The Scientific World Journal, ID 894710, 7 p, 2014. Publicador: The Scientific World Journal, ID 894710, 7 p, 2014.
Tipo: Artigo em periódico indexado (ALICE)
EN
Relevância na Pesquisa
76.02%
Abstract: The objective of our study was to characterize and determine the patterns of genetic control in relation to tolerance and efficiency of nitrogen use by means of a complete diallel cross involving contrasting inbred progenies of tropical maize based on a univariate approach within the perspective of a multivariate mixed model. Eleven progenies, previously classified regarding the tolerance and responsiveness to nitrogen, were crossed in a complete diallel cross. Fifty-five hybrids were obtained. The hybrids and the progenies were evaluated at two different nitrogen levels, in two locations. The grain yield was measured as well as its yield components. The heritability values between the higher and lower nitrogen input environment did not differ among themselves. It was observed that the general combining ability values were similar for both approaches univariate and multivariate, when it was analyzed within each location and nitrogen level. The estimate of variance of the specific combining ability was higher than general combining ability estimate and the ratio between them was 0.54. The univariate and multivariate approaches are equivalent in experiments with good precision and high heritability. The nonadditive genetic effects exhibit greater quantities than the additive genetic effects for the genetic control of nitrogen use efficiency.; 2014

Strategic applications of nitrogen fertiliser to increase the yield and nitrogen use efficiency of wheat.

Hooper, Peter
Fonte: Universidade de Adelaide Publicador: Universidade de Adelaide
Tipo: Tese de Doutorado
Publicado em //2010
Relevância na Pesquisa
96.06%
In southern Australia a large proportion of crop nitrogen requirements are usually applied early in the season, either just before or at sowing, or during the first 6-8 weeks after sowing. However, the time of greatest demand for nitrogen by wheat crops is during the stem-elongation phase when the crop is growing fastest, while early demand for nitrogen is small. The study utilised two field sites in South Australia (Hart and Mintaro) over two seasons (2003-04) to examine the effect of delayed applications of nitrogen fertiliser on nitrogen use efficiency (NUE) to dryland wheat. Treatments were applied to manipulate the crop canopy and to measure the balance between canopy size and structure and crop nitrogen uptake. In both seasons and sites significant (P<0.05) grain yield increases were obtained by later nitrogen application times. Grain protein also increases with rate of applied nitrogen and delayed time of application, with the 1st node (GS31) treatment generally producing the highest values. Applying higher rates of nitrogen fertiliser reduced NUE, while later applications were able to increase NUE. Canopy manipulation was able to increase crop nitrogen uptake, coinciding with improved grain yield formation. Generally, the data suggest that the nitrogen taken up later in the season is used very efficiently by the crop. The experiments outlined in this thesis showed that there is potential to improve NUE in dryland wheat grown in southern Australia...

The response of the maize nitrate transport system to nitrogen demand and supply across the lifecycle

Garnett, T.; Conn, V.; Plett, D.; Conn, S.; Zanghellini, J.; MacKenzie, N.; Enju, A.; Francis, K.; Holtham, L.; Roessner, U.; Boughton, B.; Bacic, A.; Shirley, N.; Rafalski, A.; Dhugga, K.; Tester, M.; Kaiser, B.
Fonte: Blackwell Publishing Ltd Publicador: Blackwell Publishing Ltd
Tipo: Artigo de Revista Científica
Publicado em //2013 EN
Relevância na Pesquisa
75.92%
An understanding of nitrate (NO3-) uptake throughout the lifecycle of plants, and how this process responds to nitrogen (N) availability, is an important step towards the development of plants with improved nitrogen use efficiency (NUE). NO3- uptake capacity and transcript levels of putative high- and low-affinity NO3- transporters (NRTs) were profiled across the lifecycle of dwarf maize (Zea mays) plants grown at reduced and adequate NO3-. Plants showed major changes in high-affinity NO3- uptake capacity across the lifecycle, which varied with changing relative growth rates of roots and shoots. Transcript abundances of putative high-affinity NRTs (predominantly ZmNRT2.1 and ZmNRT2.2) were correlated with two distinct peaks in high-affinity root NO3- uptake capacity and also N availability. The reduction in NO3- supply during the lifecycle led to a dramatic increase in NO3- uptake capacity, which preceded changes in transcript levels of NRTs, suggesting a model with short-term post-translational regulation and longer term transcriptional regulation of NO3- uptake capacity. These observations offer new insight into the control of NO3- uptake by both plant developmental processes and N availability, and identify key control points that may be targeted by future plant improvement programmes to enhance N uptake relative to availability and/or demand.; Trevor Garnett...

Evaluation of nitrogen use efficiency (NUE) in wheat.

Abdullah Faraj, Bahaddin
Fonte: Universidade de Adelaide Publicador: Universidade de Adelaide
Tipo: Tese de Doutorado
Publicado em //2013
Relevância na Pesquisa
96.08%
Nitrogen fertilizers are a major input required for cereal crop production worldwide. The management of this resource is a significant challenge to most agricultural systems as it can have significant impacts on yield and the environment. The use of applied nitrogen fertilisers in cereals is poor, where only 30-40% is actually used by cereals and the remainder lost to the environment by surface runoff, soil denitrification and volatilization (Ehdaie et al., 2010; Butterbach-Bahl and Dannenmann 2011). Improving cereal nitrogen use efficiency (NUE) is imperative to achieve yield and quality with less direct N inputs. In this study, experiments were conducted in 2010 to evaluate the effect of N fertilizer application (0, 50, 100, 150 kg urea/ha) on the growth and yield of wheat varieties at specific locations across South Australia while a small pilot glasshouse study was conducted at the Waite Campus, Adelaide University. The field experiments were designed as a randomised split-plot with three replications for each wheat cultivar and N treatment. Plant response to N treatment was measured through estimates of plant height, leaf chlorophyll content (SPAD meter), plant spike number, grain yield, 1000 grain weight, shoot biomass weight...

Improving crop nitrogen use in dryland farming: interactions and potential trade-offs between water- and nutrient-use efficiency

Garnett, T.P.; Rebetzke, G.J.
Fonte: John Wiley & Sons Publicador: John Wiley & Sons
Tipo: Parte de Livro
Publicado em //2013 EN
Relevância na Pesquisa
86.06%
Improved nitrogen-use efficiency and water-use efficiency (WUE) of dryland farming crops are important goals for cereal breeders. There have been considerable efforts to improve these traits separately, but now there is an increasing demand for crops with improvement in both of these traits. Analysis of ecological and crop-based experimental data has identified an apparent trade-off between N-use efficiency and WUE, suggesting that the two breeding goals are not compatible. This review summarises the physiology underlying these two traits and the genetic/breeding efforts underway to improve them. It then examines the observed interaction between N-use efficiency and WUE. Understanding the nature of this interaction provides scope to maximise yields in water-limiting environments whilst minimising N losses. Strategies focussing on genetic improvement to improve both traits concurrently are then discussed.; Trevor P. Garnett and Greg J. Rebetzke; Published Online: 10 JAN 2013

Bivariate models for the analysis of internal nitrogen use efficiency: mixture models as an exploratory tool.

Munoz Santa, Isabel
Fonte: Universidade de Adelaide Publicador: Universidade de Adelaide
Tipo: Tese de Doutorado
Publicado em //2014
Relevância na Pesquisa
96.09%
Ratios are commonly used among plant and soil scientists, in particular to express the plant nutrient utilisation efficiency of macro- and micro-nutrients. The internal nutrient efficiency can be understood in terms of maximising yield per a unit of nutrient in the plant. At present, IEɴ data are usually collected from designed field trials where different treatments are applied (e.g. fertiliser treatments) and analysed by univariate linear mixed models. However, univariate linear models on the ratio do not maintain information on the original traits, including their correlation, which presents a challenge when interpreting the effect of agronomic practices or environmental conditions on the process of nutrient conversion into grain. Moreover, the distributional properties of ratios do not comply with the assumptions of these linear models favoured in the area of soil and plant science research. A more suitable approach is to collect the traits of interest and to use bivariate analyses. These analyses preserve the information on the original traits and avoid issues associated with the ratio distributional properties. If the data comes from field studies, different experimental and environmental conditions may lead to the presence of patterns (groups) in the data in addition or concurrently with designed treatments. Researchers in plant and soil sciences may be interested in identifying those conditions...

Nitrogen availability, leaf life span and nitrogen conservation mechanisms in leaves of tropical trees; Disponibilidade de nitrogênio, longevidade foliar e mecanismos de conservação de nitrogênio em folhas de espécies arbóreas tropicais

Corte, Guilherme Nascimento; Macchiaverni, Patrícia; Fabbro, Inácio Maria Dal; Haddad, Claudia Regina Baptista
Fonte: Universidade de São Paulo. Escola Superior de Agricultura Luiz de Queiroz Publicador: Universidade de São Paulo. Escola Superior de Agricultura Luiz de Queiroz
Tipo: info:eu-repo/semantics/article; info:eu-repo/semantics/publishedVersion; ; ; ; ; Formato: application/pdf
Publicado em 01/12/2009 ENG
Relevância na Pesquisa
76.08%
Perenifólias de clima temperado são dominantes em solos pouco férteis. Essa característica é atribuída a mecanismos mais eficientes de economia de nutrientes. O cajueiro (Anacardium occidentale - Anacardiaceae), uma espécie decídua, é nativo de região do Brasil com solos arenosos, enquanto que o urucuzeiro (Bixa orellana - Bixaceae), uma perenifólia, nativa da América tropical, é espontâneo em regiões com solo mais úmido e fértil. As perenifólias apresentam folhas robustas, adaptadas a resistir a adversidades por mais tempo. Compararam-se aspectos físicos das folhas e mecanismos de economia de nutrientes entre as duas espécies, a fim de verificar se a espécie decídua apresenta mecanismos mais eficientes, que expliquem sua ocorrência em locais pouco férteis. Foram também comparados os mecanismos de economia de nitrogênio sob disponibilidades diferentes deste nutriente. Foram avaliados: (i) longevidade foliar, (ii) características físicas das folhas (massa por área e tensão de ruptura), (iii) concentração de compostos nitrogenados nas folhas (nitrogênio, clorofila e proteínas), (iv) mecanismos de conservação de nitrogênio (eficiência de reaproveitamento, proficiência de reaproveitamento e eficiência do uso)...

Response of chile pepper (Capsicum annuum L.) to salt stress and organic and inorganic nitrogen sources: II. Nitrogen and water use efficiencies, and salt tolerance

Huez-López,Marco A.; Ulery,April L.; Samani,Zohrab; Picchioni,G.; Flynn,R. P.
Fonte: Universidad Autónoma de Yucatán, Facultad de Medicina Veterinaria Publicador: Universidad Autónoma de Yucatán, Facultad de Medicina Veterinaria
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/12/2011 EN
Relevância na Pesquisa
76.07%
The response to two nitrogen sources on water and nitrogen use efficiencies, and tolerance of salt-stressed chile pepper plants (Capsicum annuum L.) cv. Sandia was investigated in a greenhouse experiment. Low, moderate and high (1.5, 4.5, and 6.5 dS m-1) salinity levels, and two rates of organic-N fertilizer (120 and 200 kg ha-1) and 120 kg ha-1 of inorganic fertilizer as ammonium nitrate were arranged in randomized complete block designs replicated four times. The liquid organic-N source was an organic, extracted with water from grass clippings. Water use decreased about 19 and 30% in moderate and high salt-stressed plants. Water use efficiency decreased only in high salt-stressed plants. Nitrogen use efficiency decreased either by increased salinity or increased N rates. An apparent increase in salt tolerance was noted when plants were fertilized with organic-N source compared to that of inorganic-N source.

Nitrogen use efficiency by cotton varieties

Araújo,Érica de Oliveira; Camacho,Marcos Antonio; Vincensi,Marion Martins
Fonte: Sociedade de Ciências Agrárias de Portugal Publicador: Sociedade de Ciências Agrárias de Portugal
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2013 EN
Relevância na Pesquisa
76.13%
This study aimed to evaluate the nitrogen use efficiency by different cotton varieties in an Acrisol. The design was com- pletely randomized in a 5x2x5 factorial. The factors consisted of five nitrogen rates (0, 250, 500, 750 and 1000 mg dm-3 of soil), two cotton genotypes (FiberMax 910 and FiberMax 966) and five repetitions, using urea as source N (45% N). The following variables were studied: dry matter production of plant shoots, nitrogen content, nitrogen concentration, N use efficiency, efficiency of nitrogen applied, physiological efficiency, agro-physiologic efficiency and recovery efficiency. The results showed that there was a significant linear effect of nitrogen application in the dry matter production, nitrogen content and nitrogen concentration of cotton plant. The nitrogen use efficiency varied with the genotypes and type of ef- ficiency calculated, and with increasing doses of N, less N was recovered by cotton plants.