De Figueiredo M.C.B.,Brazilian Agriculture Research Corporation Embrapa |
De Boer I.J.M.,Wageningen University |
Kroeze C.,Wageningen University |
Kroeze C.,Open University of the Netherlands |
And 6 more authors.
International Journal of Life Cycle Assessment | Year: 2014
Purpose: This study quantifies freshwater consumption throughout the life cycle of Brazilian exported yellow melons and assesses the resulting impact on freshwater availability. Results are used to identify improvement options. Moreover, the study explores the further impact of variations in irrigation volume, yield, and production location. Methods: The product system boundary encompasses production of seeds, seedlings, and melon plants; melon packing; disposal of solid farm waste; and farm input and melon transportation to European ports. The primary data in the study were collected from farmers in order to quantify freshwater consumption related to packing and to production of seeds, seedlings, and melons. Open-field melon irrigation was also estimated, considering the region's climate and soil characteristics. Estimated and current water consumptions were compared in order to identify impact reduction opportunities. Sensitivity analysis was used to evaluate variations in the impact because of changes in melon field irrigation, yield, and farm location. Results and discussion: This study shows that the average impact on freshwater availability of 1 kg of exported Brazilian yellow melons is 135 l H 2O-e, with a range from 17 to 224 l H2O-e depending on the growing season's production period. Irrigation during plant production accounts for 98 % of this impact. Current melon field water consumption in the Low Jaguaribe and Açu region is at least 39 % higher than necessary, which affects the quality of fruits and yield. The impact of melon production in other world regions on freshwater availability may range from 0.3 l H 2O-e/kg in Costa Rica to 466 l H2O-e/kg in the USA. Conclusions: The impact of temporary crops, such as melons, on water availability should be presented in ranges, instead of as an average, since regional consumptive water and water stress variations occur in different growing season periods. Current and estimated water consumption for irrigation may also be compared in order to identify opportunities to achieve optimization and reduce water availability impact. © 2013 Springer-Verlag Berlin Heidelberg.
Parentoni S.N.,Brazilian Agriculture Research Corporation Embrapa |
De Souza Jr. C.L.,University of Sao Paulo |
De Carvalho Alves V.M.,Brazilian Agriculture Research Corporation Embrapa |
Gama E.E.G.,Brazilian Agriculture Research Corporation Embrapa |
And 12 more authors.
Maydica | Year: 2010
Information available from full cycle maize trials regarding the inheritance of phosphorus (P) efficiency in tropical maize is limited. This type of information is essential to establish selection strategies for these characteristics. The objective of this study was to investigate the inheritance and relationships between characteristics related to phosphorus efficiency in tropical maize. Six tropical maize lines with contrasting P efficiency and seven F 1 crosses derived from these lines were used in this study. The parental lines, the F 1's, F 2's, BC 1P 1, BC 1P 2, BC 2P 1 and BC 2P 2 from each of the seven crosses were evaluated in three low P and two high P environments. Efficiency traits evaluated were: grain yield (GY), stover yield, (SY), grain P concentration (GPC), stover P concentration (SPC), P acquisition efficiency (PAE), P internal utilization efficiency (PUTIL), P harvest index (PHI) and the quotient of P utilization (QUTIL). Anther silk interval (ASI), which has been related to drought tolerance, was also determined. For each trait, the following parameters were estimated: mean effect (m), additive effects (a), dominant effects (d) and epistatic digenic effects (aa, ad, dd). A 47% mean yield reduction was observed at the low P level compared with the high P level in the soil. Dominance effects and epistatic effects (when detected) were more important than additive effects for the majority of the traits studied. A low correlation for PAE was observed between low and high P environments, suggesting that different mechanisms of soil P acquisition occur in low and high P environments. For the PUTIL a high correlation was observed between low and high P environments, suggesting that similar plant internal mechanisms occur in both soil P levels. A medium and negative correlation was observed between ASI and GY at low P environments. Our results suggest that the selection criteria adequate to select for P efficiency include GY under low P environments to determine PAE under low P soils, and grain P concentration under high P environments to determine PUTIL.
Ferreira F.P.,University of South Santa Catarina |
Vidal-Torrado P.,University of Sao Paulo |
Otero X.L.,University of Santiago de Compostela |
Buurman P.,Wageningen University |
And 3 more authors.
Journal of Soils and Sediments | Year: 2013
Purpose: To characterise soil humic acids (HAs) extracted from Spanish marshes formed under different vegetation types (Spartina maritima (GSp), Juncus maritimus (GJc), Phragmites australis (GPh), and Scirpus maritimus (VSc)), soil depths (0-20, 20-40 and 40-60 cm), physiographic position (low and high marshes), wetland types (salt marshes and lagoons) and environmental conditions (Atlantic and Mediterranean coast). Material and methods: Soil samples were collected in five Spanish marshes, three on the Galicia province and two on the Valencia province. Humic acids were extracted and their elemental composition, semiquinone-type free radical (SFR) content, FTIR and CPMAS 13C NMR spectra determined. Total carbon (TC), total nitrogen (TN), total sulphur (TS), CaCO3 content, and field pH and Eh (mV) in the marsh soils sampled were also measured. Results and discussion: The field pH and Eh values were typical of coastal areas submitted to periodic inundations and the highest TC, TN and TS contents were found in the soil of lagoon marshes as an effect of physiographic position and wetland type. The HAs, in general, were highly aliphatic and exhibited a low SFR content, which suggests a low humification degree of the SOM formed in the studied areas. This is a result of the anaerobic decomposition to which SOM is submitted and the high input of plant-derived organic matter (OM) by vegetation. However, among the studied sites low salt marsh and subsurface layer of the high salt marsh showed higher SFR content, simpler FTIR spectra, higher lignin degradation and lower O-alkyl C/alkyl C ratio than the lagoon marshes, thus suggesting the presence of a more humificated SOM in these sites. Conclusions: From the different factors analysed, only physiographic position (low versus high salt marshes) and wetland type (marshes versus lagoons) caused variations in the HAs characteristics, because as the studied soils are under anaerobic conditions, they control the exportation of plant-derived OM and the allochthonous OM contribution in the studied areas. © 2012 Springer-Verlag Berlin Heidelberg.
Carvalho M.A.,Brazilian Agriculture Research Corporation Embrapa |
Quesenberry K.H.,University of Florida |
Gallo M.,University of Florida
Plant Systematics and Evolution | Year: 2010
Arachis pintoi accessions were used to study genetic diversity using RAPD markers. Concurrently, two tissue culture protocols were evaluated for organogenesis and the capacity to generate somaclonal variation. Data were collected on callus growth, callus weight gain, and number of regenerated plants. Robust RAPD profiles were obtained and eight primers amplified 100 different bands with 98% polymorphisms. The proportion of polymorphic RAPD loci was 89%. Average genetic distance was 0.36 and indicated that a large amount of genetic diversity exists within the germplasm evaluated. Genetic distances were used to prepare a dendogram for the A. pintoi accessions that separated them into four groups. A large degree of variability for callus induction and callus weight gain was observed among the accessions. Shoot regeneration was achieved for several accessions on both media with no structures indicative of somatic embryogenesis detected. Root induction was difficult to obtain, and many shoots died during this process. RAPD band profiles of regenerated tissue culture plants were similar to their parent plants, and therefore no somaclonal variation was evident using these methods. © 2010 Springer-Verlag.
Carvalho M.A.,Brazilian Agriculture Research Corporation Embrapa |
Quesenberry K.H.,University of Florida
Archivos de Zootecnia | Year: 2012
Arachis pintoi germplasm displayed great variability with respect to adaptation, dry matter yield, nutritive value, seed production, and nematode reaction. Average forage dry matter yield (FDMY) during the year 2003 was 4.35 Mg/ ha, and ranged from zero to 9.10 Mg/ha. Crude protein and in vitro organic matter digestibility (IVOMD) were high and confirmed the fact that A. pintoi has excellent nutritive value. Average CP was 180 g/kg of DM and ranged from 130 to 220 g/kg of DM. IVOMD averaged 670 g/kg of DM and ranged from 600 to 730 g/kg of DM. Some accessions produced high seed yields reaching values above 1 Mg/ha, 18 and 30 months after sowing. The average seed production was 0.32 Mg/ha in 2003, and 0.43 Mg/ha in 2004. Overall, accessions PI 604817, 497574, 604815, 604810, 604808, and 604857 were the best adapted to the north central Florida environment and with the best agronomic characteristics. This research strength that general conclusions about the adaptation and agronomic value of a species to a particular environment should not be based on a single or a few germplasm lines.
Segnini A.,International Potato Center |
Segnini A.,Brazilian Agriculture Research Corporation Embrapa |
Posadas A.,International Potato Center |
Posadas A.,Brazilian Agriculture Research Corporation Embrapa |
And 5 more authors.
Soil Science Society of America Journal | Year: 2010
Wetlands are valuable for their function as C sinks, water conservation and filtering, flood control, and as a recreational landscape. In the Central and Southern Andes, peatlands (a.k.a., bofedales) are also a source of good quality pastures for wild and domestic South American camelids [Vicugna pacos, Lama glama, and Vicugna vicugna), In the present study, whole soil samples from seasonally and permanendy flooded bofedales were analyzed using laser-induced fluorescence spectroscopy (LIFS) and electron paramagnetic resonance (EPR) to assess soil organic matter (SOM) stability. The results obtained by both techniques were comparable [R2 = 0.88) and proven to be reliable indicators of increased or reduced SOM stability and thus suitable methods for assessing its humification index. The humification values determined in the permanently flooded bofedal were lower than for the seasonally flooded one. Deeper in the soil profiles of both bofedal types, the humification process of SOM attains more advanced stages, with a relative increase of more recalcitrant organic compounds, An important factor is the presence of water in permanendy flooded bofedales, which slows down organic matter decomposition due to anaerobiosis. Results from a portable LIFS system also showed significant correlations when compared with both the bench LIFS system [R2 = 0.88) and the EPR [R2 = 0.62). The portable system constitutes an affordable option for the in situ characterization of SOM. This assessment is of outmost importance in agroecosystems acting as green house gases sink or sources under variable climatic conditions. © Soll Science Society of America, 5585 Guilford Rd., Madison WI 53711 USA All rights reserved.