Potential use of the veris apparent EC sensor to predict soil texture under the semi-arid conditions of central Arizona

The operational details of the apparent electrical conductivity (ECa) sensor manufactured by Veris Technologies have been extensively documented in literature reports, but the geographical distribution of these research studies indicate a strong regional concentration in the US Mid-west and Southern states. The agricultural lands of these states diverge significantly to the soil conditions and water regime of irrigated land in the US South-western states such as Arizona where there is no previous research reports of the use of this particular sensor. The objectives of the present study were to analyze the performance of this sensor under the conditions of typical soils in irrigated farms of Central Arizona. We tested under static conditions the performance of the sensor on three soils of contrasting texture. Observations were collected as time series data as soil moisture changed from saturation to permanent wilting point. Observations were repeated at the hours of lowest and highest temperatures. In addition, this study included soil penetration resistance and salinity determinations. Preliminary results indicate that soil temperature of the upper layer caused the most dynamic change in the sensor output. The ECa curves of the three soil textures tested had well defined distinctive characteristics. Final multivariate analysis is pending.

Non-agricultural rural employment in Central America

Includes bibliography

Are Central American export specialization patterns "sticky"?

Includes bibliography

Belize: effects of climate change on agriculture

Incluye Bibliografía

Global economic developments, 1999

Includes bibliography

Suspensões de Poisson, ergodicidade e o teorema central do limite

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

The economics of climate change in Central America: summary 2010

Includes Bibliography

Federação Russa e OTAN: uma análise das políticas de Moscou em relação a Aliança Ocidental

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

ICT and Agriculture

Building a regional future Marcelo Bosch .-- ICTs as a tool for overcoming asymmetries in Latin American agriculture Mônica Rodrigues .-- “The impact of ICTs on agriculture is huge”, interview with Raúl Hopkins .-- Priorities and policies for ICT use in the Bolivian agricultural sector Víctor Vásquez Mamani .-- “To strengthen the impact of ICTs on public institutions, the end user must be established as the central objective”, interview with Hugo Chavarría .-- “ICT development must be focused on the small producer”, interview with Blas Espinel .-- “Our experiences can be replicated in the region”, interview with Francine Brossard .-- facts and figures.

An assessment of the economic impact of climate change on the Agriculture Sector in Jamaica

The agricultural sector‟s contribution to GDP and to exports in Jamaica has been declining with the post-war development process that has led to the differentiation of the economy. In 2010, the sector contributed 5.8% of GDP, and 3% to the exports (of goods), but with 36% of employment, it continues to be a major employer. With a little less than half of the population living in rural communities, agricultural activities, and their linkages with other economic activities, continue to play an important role as a source of livelihoods, and by extension, the economic development of the country. Sugar cane cultivation has, with the exception of a couple of decades in the twentieth century when it was superseded by bananas, dominated the agricultural export sector for centuries as the source of the raw materials for the manufacture of sugar for export. In 2005, sugar cane itself accounted for 6.4% of the sector‟s contribution to GDP, and 52% of the contribution of agricultural exports to GDP. Production for the domestic market has long been the larger subsector, organized around the production of root crops, especially yams, vegetables and condiments. To analyse the potential impact of climate change on the agricultural sector, this study selected three important crops for detailed examination. In particular, the study selected sugar cane because of its overwhelming importance to the export subsector of agriculture, and yam and escallion for both their contribution to the domestic subsector as well as the preeminent role yams and escallion play in the economic activities of the communities in the hills of central Jamaica, and the plains of the southwest respectively. As with other studies in this project, the methodology adopted was to compare the estimated values of output on the SRES A2 and B2 Scenarios with the value of output on a “baseline” Business As Usual (BAU), and then estimate the net benefits of investment in the relevant to climate change for the selected crops. The A2 and B2 Scenarios were constructed by applying forecasts of changes in temperature and precipitation generated by INSMET from ECHAM inspired climate models. The BAU “baseline” was a linear projection of the historical trends of yields for each crop. Linear models of yields were estimated for each crop with particular attention to the influence of the two climate variables – temperature and precipitation. These models were then used to forecast yields up to 2050 (table1). These yields were then used to estimate the value of output of the selected crop, as well as the contribution to overall GDP, on each Scenario. The analysis suggested replanting sugar cane with heat resistant varieties, rehabilitating irrigation systems where they existed, and establishing technologically appropriate irrigation systems where they were not for the three selected crops.

Climate change in Central América: Potential impacts and public policy options

Since 2008 we have supported the collaborative initiative "Economics of Climate Change in Central America" aimed at demonstrating the impacts of climate variability and change and fostering a discussion on public policies in key sectors. The initiative has been led by the Ministries of Environment and Treasury or Finance of Central America, with the support of their ministerial councils, CCAD, COSEFIN, and Economic Integration Secretariat, SIECA. The Ministries of Agriculture and of Health, with their councils, CAC and COMISCA, have also joined the effort; and the Dominican Republic came on board in 2015.

O processo de desenvolvimento geoeconômico do complexo agroindustrial cooperativista na mesorregião norte central paranaense

Pós-graduação em Geografia - FCT

Mapeamento de atributos do solo para o planejamento da irrigação sob pivô central

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Optimization of the sampling scheme for maps of physical and chemical properties estimated by kriging

The sampling scheme is essential in the investigation of the spatial variability of soil properties in Soil Science studies. The high costs of sampling schemes optimized with additional sampling points for each physical and chemical soil property, prevent their use in precision agriculture. The purpose of this study was to obtain an optimal sampling scheme for physical and chemical property sets and investigate its effect on the quality of soil sampling. Soil was sampled on a 42-ha area, with 206 geo-referenced points arranged in a regular grid spaced 50 m from each other, in a depth range of 0.00-0.20 m. In order to obtain an optimal sampling scheme for every physical and chemical property, a sample grid, a medium-scale variogram and the extended Spatial Simulated Annealing (SSA) method were used to minimize kriging variance. The optimization procedure was validated by constructing maps of relative improvement comparing the sample configuration before and after the process. A greater concentration of recommended points in specific areas (NW-SE direction) was observed, which also reflects a greater estimate variance at these locations. The addition of optimal samples, for specific regions, increased the accuracy up to 2 % for chemical and 1 % for physical properties. The use of a sample grid and medium-scale variogram, as previous information for the conception of additional sampling schemes, was very promising to determine the locations of these additional points for all physical and chemical soil properties, enhancing the accuracy of kriging estimates of the physical-chemical properties.

Aplicação de modelagem hidrológica associada à análise geoespacial, para caracterização da vazão na micro Central Hidroelétrica Ilha Anchieta - SP

Pós-graduação em Engenharia Mecânica - FEG