Rice–shrimp farming in the Mekong Delta: biophysical and socioeconomic issues

Crop Production/Industries, Farm Management, Livestock Production/Industries,

The economics of land degradation and technological change: a case study in Vietnam

This paper explores the economics of land degradation in the rice-shrimp system in the Mekong Delta of Vietnam. A bioeconomic NPV model was developed to evaluate and compare the long-term benefits of alternative production choices and farm technologies. There is an alternative rice-shrimp technology emerging in Vietnam that does not have the same land degrading impacts as the 'traditional' system, however the high capital outlay and risk associated with such technology presents its own problems. In the paper the economic incentives for adoption of the non-land degrading rice-shrimp technology are explored. Conclusions are drawn with regard to the opportunity cost of land degradation and technological change. Some conclusions are also provided on the policy implications arising from the results presented.land degradation, technological change, Vietnam, Environmental Economics and Policy,

Informing conservation policy design through an examination of landholder preferences:A case study of scattered tree conservation in Australia

AbstractChoosing effective policy instruments to achieve conservation goals has many challenges. We explore the challenge of instrument choice in the context of landscape-scale conservation on private land, where the challenge is to select instruments that are able to influence the management practices of large numbers of landholders with diverse values, beliefs and management priorities. We report on a landholder survey and workshop undertaken as part of a study focused on reversing scattered tree decline on private grazing land in Australia. We examined eight policy instruments against stated selection criteria in the context of four land management practices with potential to reverse tree decline: rotational grazing, tree planting, direct seeding of tree species, and reduced chemical fertilisers. Two of the four management practices (rotational grazing and tree planting) received much stronger support. Respondents considered all eight policy instruments more effective for supporting their uptake of these two practices compared to less preferred practices. Landholders preferred policy instruments providing short-term financial or material support, compared to longer-term instruments such as legal regulations or stewardship programs. The nature of the management practice on the production-conservation continuum significantly influenced landholder preferences for policy instruments: different instruments were preferred for conservation-oriented practices versus production-oriented practices. Our results support the conclusion that reversing scattered tree decline at the landscape-scale is best achieved by providing landholders with flexibility through offering multiple options in terms of both policy instruments and management practices

Partial replacement of soybean meal by urea or starea for lactating dairy goats

Trinta e três cabras leiteiras foram utilizadas para avaliar o efeito da substituição parcial do farelo de soja por ureia ou amireia (ureia + milho extrusado) sobre a produção e composição do leite e a concentração plasmática de glicose, nitrogênio ureico e ácidos graxos não-esterificados. Os animais foram distribuídos em delineamento de blocos completos casualizados, com três dietas experimentais e onze repetições. As dietas experimentais, todas isonitrogenadas, foram compostas de 40% de silagem de milho e 60% de concentrado e diferiram apenas quanto às fontes nitrogenadas (farelo de soja, farelo de soja + 2,8% de amireia ou farelo de soja + 1,5% de ureia). As fontes nitrogenadas utilizadas nas dietas não influenciaram o consumo de matéria seca, a produção de leite, a produção de leite corrigida para 3,5% de gordura, nem os teores de gordura e proteína no leite. A concentração de glicose e ácidos graxos não-esterificados no plasma não foi alterada pela fonte de nitrogênio. Entretanto, a concentração de nitrogênio ureico plasmático na colheita após a quarta semana experimental foi menor nos animais que receberam o farelo de soja. A concentração plasmática de glicose, nitrogênio ureico e ácidos graxos não-esterificados foi semelhante entre as fontes de nitrogênio não-proteico, independentemente da forma utilizada. O uso da ureia na forma extrusada (amireia) não apresenta vantagem em relação à ureia utilizada na forma convencional.Thirty-three dairy goats were used to evaluate the effects of partial replacement of soybean meal by urea or starea (urea + extruded corn) on milk production and composition and plasma glucose, urea nitrogen and nonesterified fatty acids concentrations. The animals were distributed in a randomized complete block design, with three experimental diets and eleven replicates. All the experimental diets were isonitrogenous, composed by 40% corn silage and 60% concentrate, with different nitrogenous sources (soybean meal, soybean meal + 2.8% starea or soybean meal + 1.5% urea). The nitrogenous sources used in the diets did not influence dry matter intake, milk production, milk production corrected for 3.5% fat-corrected milk, neither milk fat and protein contents. Plasma glucose and non-esterified fatty acids concentrations were not modified by nitrogen sources. However, plasma urea nitrogen concentration in the harvest after the fourth experimental week was lower for animals fed soybean meal diet. Plasma concentration of glucose, urea nitrogen and non-esterified fatty acids were similar among non-protein nitrogen sources, regardless to the way it was used. Urea used in the extruded form (starea) has no advantage compared to the urea used in the conventional form

Desempenho de cordeiros Santa Inês em dietas com teores variáveis de proteína bruta

A controvérsia sugerida na literatura aponta a necessidade de uma maior averiguação das necessidades protéicas de cordeiros (Ovis aries) em crescimento, terminados em confinamento e alimentados com dietas de alta proporção de concentrado. Este trabalho avaliou a influência de teores de proteína bruta (PB) em dietas com alta proporção de concentrado sobre o desempenho e características de carcaça de cordeiros deslanados, confinados por 56 dias. Foram utilizados 48 cordeiros da raça Santa Inês (peso inicial de 18,4 ± 0,4 kg; idade inicial de 86 ± 2 dias), sendo distribuídos 2 animais por baia, em um delineamento experimental em blocos casualizados com 4 tratamentos e 6 repetições. As dietas experimentais continham 80% de concentrado e 20% de bagaço de cana-de-açúcar, com teores de 14, 16, 18 ou 20% PB na matéria seca. Não houve diferença entre os tratamentos para ganho de peso, os quais foram 228, 220, 230 e 231 g d-1 para as dietas com 14, 16, 18 e 20% PB, respectivamente. Não houve diferença entre os tratamentos para consumo de matéria seca e conversão alimentar, cujos valores foram 1,03; 1,02; 1,08 e 1,10 kg d-1 e 4,19; 4,28; 4,35 e 4,44 kg MS kg-1 de ganho para as dietas com 14, 16, 18 e 20% PB, respectivamente. A concentração de N uréico plasmático aumentou linearmente para as dietas contendo teores crescentes de PB. Não houve diferença entre os tratamentos para as características de carcaça.Differences among dietary protein levels suggested in the literature point out to the need for better evaluation of protein requirements of growing lambs, raised in drylot on a high-concentrate diet. This study evaluates the influence of crude protein (CP) levels in high concentrate diets on performance and carcass traits of ram lambs, confined for 56 days. Forty eight (48) Santa Ines lambs (initial body weight 18.4 ± 0.4 kg; 86 ± 2 days old) were fed 4 experimental diets containing 14, 16, 18 or 20% CP, in a completely randomized block design. Diets consisted of 80% concentrate and 20% sugarcane bagasse. There were no differences in average daily gain: values of 228, 220, 230 and 231 g d-1 were obtained for diets containing 14, 16, 18 and 20% CP, respectively. There were no differences in dry matter intake and feed conversion: values were 1.03; 1.02; 1.08 and 1.10 kg d-1; 4.19; 4.28; 4.35 and 4.44 kg DM kg-1 gain for diets with 14, 16, 18 and 20% CP, respectively. Plasma urea nitrogen concentrations increased linearly as diets contained more CP. There were no differences in carcass traits

A digitalização de quatro herbários da Amazônia e seus equipamentos, processos e atual situação

O herbário é uma coleção botânica destinada a catalogação de materiais botânicos e auxiliar estudos referentes a estes. Nos dias atuais, faz-se necessário que essas instituições se modernizem, de modo a fazer fluir o conhecimento concentrado nas coleções para o resto da sociedade. Uma das maneiras é a digitalização das coleções, transformando o material antes apenas em formato fí­sico, agora também em formato digital. O trabalho que se segue aplicou um questionário para quatro herbários na região amazônica, com o intuito de recolher informações sobre os processos aplicados na digitalização de suas respectivas coleções. Notou-se a diversidade de equipamentos utilizados, variando de acordo com o tamanho das coleções e o investimento que as mesmas recebem, assim como os processos envolvidos

Direct Evidence for Octupole Deformation in 146^{146}Ba and the Origin of Large E1E1 Moment Variations in Reflection-Asymmetric Nuclei

Despite the more than one order of magnitude difference between the measured dipole moments in $^{144}$Ba and $^{146}$Ba, the strength of the octupole correlations in $^{146}$Ba are found to be as strong as those in $^{144}$Ba with a similarly large value of $B(E3;3^- \rightarrow 0^+)$ determined as 48($^{+21}_{-29}$) W.u. The new results not only establish unambiguously the presence of a region of octupole deformation centered on these neutron-rich Ba isotopes, but also manifest the dependence of the electric dipole moments on the occupancy of different neutron orbitals in nuclei with enhanced octupole strength, as revealed by fully microscopic calculations.Comment: 6 pages, 5 figures, accepted for publication in Phys. Rev. Let

Aerobic biodegradation of butanol and diesel oil blends

This work aimed to evaluate the aerobic biodegradation of butanol/diesel oil blends (5, 10, 15, 20%, v/v) in comparison to the biodiesel/diesel oil blend (20%, v/v). Respirometric experiments simulating the contamination of natural environments (soil and water from a river) were carried out in biometer flasks (250 mL) used to measure microbial carbon dioxide (CO2) production. The automated turbidimeter Bioscreen C was used to follow the growth of Pseudomonas aeruginosa LBI on butanol/diesel oil blends. A redox indicator (2,6-dichlorophenol indophenol - DCPIP) test was used to evaluate the capability of four inocula to biodegrade the blends with 20% (v/v). The experiment which simulated the soil contamination demonstrated that butanol is less biodegradable than diesel oil, and for this reason the increase in the portion of butanol in the  butanol/diesel blend from 5 to 20% had negative effects on biodegradation. While in soil the biodiesel/diesel blend was more easily biodegraded than the butanol/diesel blend, in water this order was the inverse. The insoluble fuels (diesel and biodiesel) were poorly biodegraded in water and the biodegradation of the butanol/diesel blend was favored by the water solubilization of the butanol, which enhances the bioavailability of this compound. On the other hand, initial concentrations of butanol in the water higher than 10 mL L-1 inhibited the cell growth of the tested microorganisms. Thus, butanol toxicity presumably had a significant effect on the degree of biodegradation of the fuel blends.Key words: Butanol, biodiesel, diesel, biodegradation, blends, soil, water