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| Souza,Marcos André Silva; Faquin,Valdemar; Guelfi,Douglas Ramos; Oliveira,Geraldo César de; Bastos,Carla Elisa Alves. |
| O presente trabalho foi desenvolvido com o objetivo de avaliar o efeito do cultivo prévio do capim-Marandu (Brachiaria brizantha cv. Marandu), da aplicação de corretivos e da compactação do solo no acúmulo de macronutrientes pela soja cultivada em sucessão. O delineamento experimental foi inteiramente casualizado em esquema fatorial 4 x 6 x 2, com três repetições. Os fatores de estudo foram quatro densidades do solo: 1,0; 1,20; 1,40 e 1,60 Mg m-3; seis tratamentos de correção: 1) controle, sem correção; 2) calcário; 3) silicato de cálcio; 4) gesso; 5) calcário + gesso; 6) silicato de cálcio + gesso; além de dois sistemas de cultivo: com e sem cultivo prévio do capim-Marandu. As unidades experimentais foram compostas por vasos de tubos de PVC de 20 cm de... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Calcário; Densidade do solo; Gesso agrícola; Silicato de cálcio; Sistema de cultivo. |
| Ano: 2012 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1806-66902012000400001 |
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| Souza,Taylor Lima de; Guelfi,Douglas Ramos; Silva,André Leite; Andrade,André Baldansi; Chagas,Wantuir Filipe Teixeira; Cancellier,Eduardo Lopes. |
| ABSTRACT The market of stabilized, slow and controlled release nitrogen (N) fertilizers represents 1% of the world fertilizer consumption. On the other hand, the increase in availability, innovation and application of these technologies could lead to the improvement of N use efficiency in agroecossystems and to the reduction of environmental impacts. The objective of this study was to quantify agronomic efficiency relative index, ammonia volatilization, and CO2 emissions from conventional, stabilized and controlled release N fertilizers in corn summer crop. The experiment was carried out in a corn crop area located in Lavras, state of Minas Gerais, Brazil, without irrigation. All treatments were applied in topdressing at rate of 150 kg ha-1 N. N-NH3 losses... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: CO2; NH3 loss; No-tillage; Zea mays L.. |
| Ano: 2017 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1413-70542017000500494 |
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| Dominghetti,Anderson William; Guelfi,Douglas Ramos; Guimarães,Rubens José; Caputo,André Luiz Carvalho; Spehar,Carlos Roberto; Faquin,Valdemar. |
| ABSTRACT Ammonia volatilization (N-NH3) is one of the main pathways of Nitrogen loss reducing nitrogen use efficiency in coffee orchard. This work aimed at quantifying ammonia volatilization (N-NH3) losses from N-sources to be used in coffee plantations fertilization in Brazil. The experiment was conducted in the field on a dystrophic red latosol (Ferralsol in FAO's classification) at the Coffee Research Sector, University of Lavras, MG, Brazil. The experimental design was of complete randomized blocks with three repetitions of the following treatments: conventional urea, ammonium nitrate and urea + 0.15% Cu and 0.4% B, urea + anionic polymers, urea + elementary sulfur (S0) + polymers, and urea + plastic resin. These N sources were split into three doses... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Coffee arabica; Slow and controlled release and stabilized fertilizers; Ammonium nitrate; Urea. |
| Ano: 2016 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1413-70542016000200173 |
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| Chagas,Wantuir Filipe Teixeira; Emrich,Eduardo Bucsan; Guelfi,Douglas Ramos; Caputo,André Luiz Carvalho; Faquin,Valdemar. |
| In contrast to enhanced-efficiency nitrogen fertilisers, principally urea, phosphate fertilisers have been little studied and the available information is limited. The aim of this work therefore was to evaluate the productive and nutritional characteristics and the agronomic efficiency of a polymer-coated MAP fertilizer on two subsequent lettuce crops. The experiment was carried out in a greenhouse, in pots with a capacity of 4 kg, filled with a dystrophic yellow Latosol of a clayey texture. The experimental design was completely randomised and the treatments arranged in a 2 x 5 factorial scheme: two sources of phosphorus (P) (MAP and polymer-coated MAP), applied to the plots in five dosages (0, 100, 200, 400, 800 mg P2O5 kg-1) with three replications. The... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Phosphate fertilizer; Residual effect; Lactuca sativa L. |
| Ano: 2015 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1806-66902015000200266 |
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