Ammonia volatilization (N-NH 3 ) is one of the main pathways of Nitrogen loss reducing nitrogen use efficiency in coffee orchard. This work aimed at quantifying ammonia volatilization (N-NH 3 ) 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 (S 0 ) + polymers, and urea + plastic resin. These N sources were split into three doses of 150 kg ha -1 and band applied. The N-NH 3 losses by volatilization and variations of pH (H 2 O) were measured, before and after N application. The N-sources contributed to reduce the soil pH, measured after the third nitrogen fertilization. The N-NH 3 losses by volatilization (average from three applications) was as follows: urea + anionic polymers (35.8%) > conventional urea (31.2%) = urea + S 0 + polymers (31.0%) > urea + 0.15% Cu + 0.4 % B (25.6%) > urea + plastic resin (8.6%) = ammonium nitrate (1.0%).Index terms: Coffee arabica; slow and controlled release and stabilized fertilizers; ammonium nitrate; urea. RESUMOA volatilização de amônia é uma das principais causas da redução da eficiência no uso de fertilizantes nitrogenados em lavouras cafeeiras. Neste trabalho, objetivou-se quantificar as perdas de nitrogênio por volatilização de fertilizantes nitrogenados aplicados em lavoura cafeeira. O experimento foi realizado em condições de campo, em um Latossolo Vermelho distrófico, cultivado com café, localizado no Setor de Cafeicultura/Departamento de Agricultura/UFLA, Lavras -MG. O delineamento experimental foi em blocos casualizados e os tratamentos foram: ureia; nitrato de amônio; ureia + 0,15% de Cu + 0,4% de B; ureia + polímeros; ureia + enxofre elementar (S 0 ) + polímeros e; ureia + resina plástica; distribuídos em três parcelamentos com doses iguais de 150 kg ha -1 . Foram quantificadas as perdas de nitrogênio por volatilização (N-NH 3 ) e as variações no pH em água, da camada de 0-5 cm de solo, antes e depois dos parcelamentos das adubações nitrogenadas. Os fertilizantes nitrogenados reduziram os valores do pH do solo após as três adubações de manutenção. A perda de nitrogênio por volatilização dos fertilizantes nitrogenados (média das três adubações) foi: ureia + polímeros (35,8% do total do N aplicado) > ureia (31,2%) = ureia + S 0 + polímeros (31,0%) > ureia + Cu + B (25,6%) > ureia + resina plástica (8,6%) = nitrato de amônio (1,0%).Termos para indexação: Coffee arabica; fertilizantes estabilizados e de liberação controlada; nitrato de amônio; ureia.
A B S T R A C TIrrigation associated to reduction on planting spaces between rows and between coffee plants has been a featured practice in coffee cultivation. The objective of the present study was to assess, over a period of five consecutive years, influence of different irrigation management regimes and planting densities on growth and bean yield of Coffea arabica L.. The treatments consisted of four irrigation regimes: climatologic water balance, irrigation when the soil water tension reached values close to 20 and 60 kPa; and a control that was not irrigated. The treatments were distributed randomly in five planting densities: 2,500, 3,333, 5,000, 10,000 and 20,000 plants ha -1 . A split-plot in randomized block design was used with four replications. Irrigation promoted better growth of coffee plants and increased yield that varied in function of the plant density per area. For densities from 10,000 to 20,000 plants ha -1 , regardless of the used irrigation management, mean yield increases were over 49.6% compared to the non-irrigated crop.Irrigação por gotejamento em cafeeiros sob diferentes densidades de plantio: Crescimento e produtividade no Sudeste do Brasil R E S U M O Associada ao adensamento da lavoura, a irrigação tem sido prática de destaque na cafeicultura. Objetivou-se, neste trabalho, avaliar a influência de diferentes regimes de irrigação e densidades de plantio sobre o crescimento vegetativo e a produtividade média de cafeeiros Coffea arabica L, ao longo de cinco anos. Os tratamentos constaram de quatro regimes de irrigação: balanço hídrico climatológico; irrigações com base nas tensões de 20 e 60 kPa, além de uma testemunha não irrigada, os quais foram distribuídos aleatoriamente em cinco densidades de plantio 2.500; 3.333; 5.000; 10.000 e 20.000 plantas ha -1. O delineamento experimental em blocos casualizados em esquema de parcelas subdivididas foi utilizado com quatro repetições; verificou-se que a irrigação promove maior crescimento das plantas de cafeeiro e aumenta a produtividade, que varia em função da densidade de plantas por área. Obtiveram-se, para as densidades de 10.000 e 20.000 plantas ha -1 , independente do manejo da irrigação utilizado, aumentos médios de produtividade acima de 49,6% em relação ao cultivo não irrigado.
-With the aim of establishing critical ranges for the leaf nitrogen (N) and potassium (K) levels in fertigated coffee crops under production, an experiment was carried out in the experimental area of the Sector for Coffee Cultivation of the Department of Agriculture at the Federal University of Lavras, in Brazil. Treatments consisted of five levels of fertilizer applied through fertigation: 30%, 80%, 130%, 180% and 230% of the recommended amounts of N and K for rainfed coffee grown in Minas Gerais. A randomised block design with four replications was used. Critical ranges for nutrient concentrations in the leaves were established from the results of growth characteristics (plant height and stem diameter), leaf analyses and productivity. The results obtained were: a) nitrogen (g kg -1): 32
-The aim of this work was to evaluate the use of a water-retaining polymer on the initial growth of coffee plants for different levels of irrigation and types of seedling. The experiment was set up in pots with a clayey soil, in a greenhouse of the Sector for Coffee Production of the Federal University of Lavras, Brazil. The experiment was arranged in a randomised block design into sub-lots with three replications, giving a total of 48 experimental units. Four levels of irrigation (25%, 50%, 75% and 100% of the available water) were randomly assigned to the lots; the type of seedling (grown in bags or tubes) were randomly assigned to the sub-lots, and the use or not of the water-retaining polymer randomly assigned to the sub-sub-lots. In the treatments with water-retaining polymer, a dilution of 1.5 Kg of polymer to 400 litres of water was used at a dose of 1.5 litres of solution per plant. The following were evaluated at intervals of 60 days during the experiment (360 days from planting): stem diameter, plant height, leaf area, number of leaves and number of plagiotropic branches on the coffee plants. RESUMO -Objetivou-se avaliar o uso do polímero hidro retentor no crescimento inicial de cafeeiros em diferentes níveis de irrigação e tipos de mudas. O experimento foi instalado em vasos com solo argiloso, em casa de vegetação do Setor de Cafeicultura, Universidade Federal de Lavras. O experimento foi conduzido em delineamento de blocos ao acaso com parcelas sub-subdivididas e três repetições, totalizando 48 unidades experimentais. Quatro níveis de irrigação (25%; 50%; 75% e 100% de água disponível) foram aleatorizados às parcelas; os tipos de mudas (formadas em saquinho e tubete) foram aleatorizadas às sub-parcelas; e a ausência ou presença do polímero hidro retentor foram aleatorizados nas sub-subparcelas. Nos tratamentos com uso do polímero hidro retentor utilizou-se a diluição de 1,5 kg de polímero em 400 litros d'água, para utilização da dose de 1,5 litros da solução por planta. Em intervalos de 60 dias durante a condução do experimento (360 dias a partir da implantação), avaliou-se o diâmetro de caule, altura de planta, área foliar, número de folhas e número de ramos plagiotrópicos dos cafeeiros. O polímero hidro retentor hidratado beneficiou o crescimento do cafeeiro em sistema irrigado. A irrigação promoveu maior crescimento das plantas, sendo que as mudas formadas em saquinhos apresentam maior crescimento que mudas em tubetes.Palavras-chave: Recipientes de mudas. implantação. Coffea arabica L.. Hidrogel.
The aim of this study was to quantify NH3-N losses from conventional, stabilized, slow-release, and controlled-release N fertilizers in a coffee field. The N fertilizers analyzed were prilled urea, prilled urea dissolved in water, ammonium sulfate (AS), ammonium nitrate (AN), urea + Cu + B, urea + adhesive + CaCO3, and urea + NBPT (all with three split applications), as well as blended N fertilizer, urea + elastic resin, urea-formaldehyde, and urea + polyurethane (all applied only once). NH3-N losses (mean of two crop seasons) were statistically higher for urea + adhesive + CaCO3 (27.9% of applied N) in comparison with the other treatments. Loss from prilled urea (23.7%) was less than from urea + adhesive + CaCO3. Losses from urea + NBPT (14.5%) and urea + Cu + B (13.5%) were similar and lower than those from prilled urea. Urea dissolved in water (4.2%) had even lower losses than those treatments, and the lowest losses were observed for AS (0.6%) and AN (0.5%). For the single application fertilizers, higher losses occurred for urea + elastic resin (5.8%), blended N fertilizer (5.5%), and urea + polyurethane (5.2%); and urea-formaldehyde had a lower loss (0.5%). Except for urea + adhesive + CaCO3, all N-fertilizer technologies reduced NH3-N losses compared to prilled urea.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.