Browsing by Author "Trindade, H."
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- A alteração climática na “fixação” do amónio em solos cultivados com arroz (Oryza sativa) por alagamentoPublication . Figueiredo, N.; Carranca, C.; Coutinho, J.; Trindade, H.; Pereira, J.; Prazeres, A.; Marques, P.O arroz, é essencialmente produzido como monocultura, em canteiros alagados, nas regiões do centro e sul do País (Vales do Mondego, Tejo e Sado). O ião NH4 + é a forma de N mineral mais abundante e preferencialmente absorvida pelo arroz, em condições de alagamento. O alagamento potencia a mineralização, por acção dos microrganismos aeróbios facultativos, aumentando a sua concentração na solução do solo. No solo, este catião pode ser adsorvido nos colóides ou "fixado" nos minerais argilosos do tipo 2:1, tornando-se temporariamente indisponível para a cultura. A taxa de "fixação" e posterior libertação para a solução depende da textura do solo, do teor e mineralogia da argila, pH, potencial redox, temperatura e presença de outros catiões. Não se conhecem os efeitos do aumento simultâneo da concentração de CO2 na atmosfera e da temperatura na "fixação" do NH4 + , sabendo-se que, isoladamente, o aumento da temperatura potencia a "fixação". Neste estudo, avaliou-se o teor de NH4 + em dois solos (areno-franco e argilo-limoso) alagados e cultivados com arroz, em 2012, como resposta à fertilização mineral e ao alagamento. Compararam-se esses teores com os medidos no solo argilo-limoso, em condições controladas de aumento da [CO2] e temperatura. O teor de NH4 + "fixado" em ambos os solos (ar livre) foi superior ao da concentração de NH4 + disponível no respectivo solo. A concentração de NH4 + "fixada" no solo argilo-limoso manteve-se superior à do solo arenofranco, variando com os tratamentos (ar livre > CO2+temperatura = temperatura), com as datas de amostragem e com a fertilização azotada.
- Ammonia and greenhouse gas emissions from slatted and solid floors in dairy cattle houses: A scale model studyPublication . Pereira, J.; Fangueiro, D.; Misselbrook, T.H.; Chadwick, D.R.; Coutinho, J.; Trindade, H.Dairy cattle are usually housed in naturally ventilated houses where removal of excreta is periodically performed. The aim of this controlled study was to compare the effect of two floor designs and three air temperatures (5, 15 and 25 C) on NH3, N2O, CH4 and CO2 emissions arising from cattle excreta deposition to the floor. Two scale models were built to simulate a level solid floor without urine drainage, and a slatted concrete floor. Following application of a mixture of urine and faeces, these two floor type models were subjected to a constant airflow rate (12.5 exchanges h 1 ) and gaseous emissions were measured over a 72-h period. Emissions of NH3, N2O, CO2 and CH4 increased significantly with air temperature with both floor type models and emissions of NH3, N2O and CO2 were significantly greater from the solid floor relative to the slatted floor at all temperatures considered. The cumulative NH3 (27e66% of total N applied) and CO2 (<19% of total C applied) emissions were greater from the solid floor than from the slatted floor (by 36% and 44%, respectively). The cumulative N2O (<0.1% of total N applied) and CH4 (<0.4% of total C applied) emissions were relatively low and CH4 values did not differ significantly between treatments. Cumulative greenhouse gas emissions (as CO2-equivalents) increased significantly with temperature but did not differ between the floor types.
- Ammonia emissions from dairy cattle buildings and outdoor concrete yards under the Mediterranean conditions of NW PortugalPublication . Pereira, J.; Misselbrook, T.H.; Chadwick, D.R.; Coutinho, J.; Trindade, H.Around 75% of European ammonia emissions comes from livestock production and emissions occur at all stages of manure management. Ammonia emissions have never been measured in commercial dairy cattle houses in Portugal. The objective of our study was to evaluate NH3 emissions for the main types of dairy cattle buildings naturally ventilated and outdoor concrete yards in NW Portugal.
- Ammonia emissions from naturally ventilated dairy cattle buildings and outdoor concrete yards in PortugalPublication . Pereira, J.; Misselbrook, T.H.; Chadwick, D.R.; Coutinho, J.; Trindade, H.There is a lack of information on ammonia (NH3) emissions from cattle housing systems in Mediterranean countries, with most published data deriving from NW Europe. An investigation was carried out in NW Portugal to quantify NH3 emissions for the main types of dairy cattle buildings in Portugal, i.e. naturally ventilated buildings and outdoor concrete yards, and to derive robust emission factors (EFs) for these conditions and compare with EFs used elsewhere in Europe. Measurements were made throughout a 12-month period using the passive flux sampling method in the livestock buildings and the equilibrium concentration technique in outdoor yards. The mean NH3 emission factor for the whole housing system (buildings þ outdoor yards) was 43.7 g NH3eN LU 1 day 1 and for outdoor concrete yards used by dairy cattle was 26.6 g NH3eN LU 1 day 1 . Expressing NH3 emission in terms of the quantity of liquid milk produced gave similar values across the three dairy farms studied (with a mean of 2.3 kg N ton-milk 1 produced) and may have advantages when comparing different farming systems. In dairy houses with outdoor yards, NH3 emissions from the yard area contributed to 69e92% of total emissions from this housing system. Emissions were particularly important during spring and summer seasons from outdoor yards with NH3 emitted in this period accounting for about 72% of annual emissions from outdoor yards. Mean NH3 emission factors derived for this freestall housing system and outdoor concrete yards used by dairy cattle in Portugal were higher than those measured in northern Europe. In addition, values of animal N excretion estimated in this study were greater than official National standard values. If these emissions are typical for Portuguese dairy systems, then the current National inventory underestimates emissions from this source in NW of Portugal, because of the use of lower standard values of N excretion by dairy cattle.
- Assessment of net nitrogen mineralisation from repeated applications of cattle-slurry and mineral fertiliser in a Mediterranean forage systemPublication . Pereira, J.; Coutinho, J.; Trindade, H.The aim of our study was to evaluate the impact of repeated applications of cattle-slurry and mineral fertiliser on net N mineralisation rates in a Mediterranean forage system, cropped with maize silage (spring-summer) followed by Italian ryegrass (autumn-winter) for silage. The field study was performed between May-1997 and May-2000 in a commercial dairy-cattle farm located in Northwest Portugal. Five treatments were employed: Control with no N fertiliser (T0); one application of cattle-slurry at maize sowing with 187 (T1) or 340 (T2) kg total N ha-1 year-1; two applications, 258 kg total N ha-1 at maize and 150 kg total N ha-1 at ryegrass sowing plus application of 190 kg total N ha-1 to maize and 50 kg total N ha-1 to ryegrass as mineral fertiliser, totalizing 648 kg total N ha-1 year-1 (T3), and; application of 240 kg total N ha-1 year-1 as mineral fertiliser to both crops like in T3 (T4). Net N mineralisation was measured in soil layer 0-30 cm in each treatment. Significant amounts of N were released (160-290 kg N ha-1 year-1) by mineralisation due cattle-slurry application to soil, with apparent net N mineralisation varying between 45 and 95% of the total N applied. The application of mineral fertiliser led to N immobilisation (-23%) of the total N applied. Data obtained in this study may be used in the management of the N fertilisation to improve manure-N efficiency.
- A climate change scenario and soil ammonium “fixation” during the seasonal rice (Oryza sativa) growth in Portugal under intermittent floodingPublication . Figueiredo, N.; Carranca, C.; Coutinho, J.; Trindade, H.; Pereira, J.; Marques, P.; de Varennes, A.The “newly fixed” NH4 + in clay minerals should be considered for an efficient management of plant nutrition. In a clayloam soil cultivated in 2012 with rice under intermittent flooding and conventional agronomic practices, the dynamics of pH, N-inorganic and non-exchangeable NH4 + was evaluated i) under field conditions, air temperature and atmospheric [CO2 ] (375 µmol mol-1 air) in Salvaterra de Magos (Portugal), and ii) under elevated temperature and temperature+[CO2 ] in controlled microclimate. For that, open-top chambers were used to simulate the conditions of an increased mean air temperature (2-3 °C), alone or combined with increased [CO2 ] (550 µmol mol-1 air). Non-exchangeable NH4 was significantly higher under open-field conditions compared with the temperature elevation, with or without elevated atmospheric [CO2 ]. Temperature elevation reduced the “fixation” rate of the cation, while the CO2 concentration rise did not affect particularly the non-exchangeable form. Further studies are required for consolidation of these findings together with microbial communities and dynamics of C and N in soil.
- Comparação do potencial fertilizante de resíduos compostados de curtumesPublication . Pereira, j.; Perdigão, A.; Teixeira, D.; Marques, F.; Pinto, A.; Rodrigues, P.; Fangueiro, D.; Trindade, H.A indústria de curtumes produz elevadas quantidades de resíduos, ricos em nutrientes, que podem, após compostagem, ser utilizados como fertilizantes orgânicos. O objectivo deste trabalho foi comparar o potencial fertilizante de resíduos compostados provenientes da indústria de curtumes.
- Comparison of field methods to assess net N mineralization in soils under different rates of cattle-slurry application and a maize / annual ryegrass cropping systemPublication . Pereira, J.; Coutinho, J.; Moreira, N.; Trindade, H.Knowledge of the amount of N mineralized from manure applied to soil and its availability to crops is extremely important for precise fertilization practices and environment protection. The objectives of our study were to evaluate the effect of cattle-slurry application rate on net N mineralization (NNM) and compare the field methods of soil core incubation with acetylene (SIA) and the sequential in situ incubation of undisturbed soil cores (SIU) to assess N mineralization in an intensive double-cropping forage system producing maize and Italian ryegrass (winter crop) for silage.
- Composting of different agro-food wastes: Effects of the phenolic and lignocellulosic fractions on greenhouse gases emissionsPublication . Santos, C.; Fonseca, J.; Coutinho, J.; Ferreira, L.; Pereira, J.; Trindade, H.Currently, society faces a number of challenges related to the large amounts of organic wastes generated and accumulated by the increasing expansion of agroindustrial activities1. Most of these wastes are rich in lignocellulosic compounds, which represents a major fraction of all plant biomass (of above 90%), so, its degradation is crucial for global carbon cycle2. These organic wastes may be introduced directly on agriculture sector as soil organic amendment, however, these might contain phytochemicals, such as phenolic compounds which may introduce toxic effects to soil and to beneficial organisms. Transformation and degradation of these renewable organic wastes into composts (COMPOSTING) is a possible solution for these problems and an environmentally friendly processes that allows make use of natural resources efficiently3. The main potential handicap is generation and emission of greenhouse gases such as carbon dioxide (CO2 ), methane (CH4 ) and nitrous oxide (N2O) and another ones which may led serious problems like nitric oxide (NO) and ammonia (NH3) 4. For this reason, quantification of GHG emissions from composting and finding possible relations with the chemical and structural composition of the wastes used is crucial to the development of technologies for mitigating emissions and should help to make decisions concerning waste management.
- Control of ammonia emissions in naturally ventilated dairy cattle facilities in PortugalPublication . Pereira, J.; Trindade, H.Efetuou-se um estudo sobre os processos associados à emissão de NH3 em instalações naturalmente ventiladas para bovinos de leite, tendo sido descritos os fatores que regulam a emissão de NH3, assim como metodologias de medição destas emissões nestas instalações. Foram, também, identificadas técnicas adequadas de mitigação da emissão de NH3 em instalações localizadas em regiões com climas quentes. As técnicas de mitigação mais eficazes e de implementação simples incluem estratégias associadas: (i) ao projeto das instalações e pavimentos que conduzam a emissões reduzidas; (ii) à pré-excreção das dejeções, nomeadamente a utilização de dietas com teor otimizado de proteína bruta e o aumento da produção de leite ao nível da exploração; e (iii) à pósexcreção das dejeções, sobretudo pela alteração das condições de controlo ambiental no interior das instalações, introdução de práticas ou aplicação de aditivos no manejo das dejeções depositadas sobre os pavimentos.