Desempenho dinâmico de um trator agrícola utilizando biodiesel destilado de óleo residual

The objective of this study was to evaluate the dynamic performance of an agricultural tractor utilizing distilled biodiesel (50% ethylic + 50% methylic) as a function of the proportion of biodiesel and diesel of petroleum (0 and 100%, 5 and 95%, 15 and 85%, 25 and 75%, 50 and 50%, 75 and 25% and 100 and 0%), respectively. This research was done in the area of the Department of Rural Engineering of the Paulista State University (UNESP), Jaboticabal Campus, SP, located in the latitude 21° 14′ 28″ S and longitude 48° 17′12″ W. A tractor 4 x 2 FWA was used, with a 73.6 kW (100 HP) motor and a ballast tractor. The biodiesel used was produced from spent oil from food frying. The experimental design was entirely randomized, with 7 treatments and 5 repetitions, totaling 35 observations. The results showed that the biodiesel and diesel blend significantly influenced the hourly volumetric consumption, hourly mass consumption, fuel consumption per worked area and specific fuel consumption variables. When the tractor operated with 100% of biodiesel (B100) the specific fuel consumption increased 18% on average in relation to diesel (B0).

Modernidad y heterogeneidad: estilo de desarrollo agrícola y rural en América Latina y el Caribe

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El modelo agrícola de América Latina en las últimas décadas (síntesis)

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Incidencia de dos décadas de ajustes en el desarrollo agrícola de América Latina y el Caribe

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Planejamento agrícola e implantação de sistema de cultivo de cana-de-açúcar com auxílio de técnicas geoestatísticas

Sugarcane is one of the most important crops of the Brazilian agribusiness and this importance justifies the use of techniques that allow the implementation of cultivation systems capable of reducing the variability of soil characteristics and the establishment of efficient agricultural planning. The aim of the present work was the planning and implementation of cultivation systems for sugarcane using geostatistical techniques, in the Pereira Barreto region, SP. An area of 505 ha was mapped using the global positioning system (GPS) and a Digital Elevation Model was elaborated (MDE). Soil samples were collected for 0-0.25 m depth, in each 7 ha, for their chemical attributes and texture characterization. Data were analyzed by descriptive statistics and geostatistics. The determination of the spatial distribution of soil granulometric and chemical attributes allowed the allocation of the studied sugarcane varieties according to soil fertility and clay content. The kriging maps of soil granulometric and chemical attributes brought useful information to the establishment of production environments with different soil and crop managements. The identification of different environments by means of geostatistical techniques allowed the precise planning of the sugarcane cultivation, as well as the adequacy of fertilization practices and the allocation of suitable sugarcane varieties adapted to the conditions imposed by differences in the soil attributes.

Geoprocessamento e sensoriamento remoto aplicado na determinação da aptidão agrícola de uma microbacia

Soil use for the development of activities as agriculture and livestock has been causing great alterations in the environment, mainly when these are practiced intensively, disrespecting the fragility and aptitude of the natural resources. Therefore, it is essential that the planning of the agricultural activities is done, taking into consideration the several environmental criteria involved in the decision-making process. Thus, this study aimed to analyze the agricultural aptitude classes of lands from a watershed through geographical information system (GIS). The Arroio Ajuricaba watershed is located in the Municipality of Marechal Cândido Rondon - PR among the coordinates UTM 787309m E and 793892m E; 7275026m N and 7281310m N, in the Spindle 21, presenting an area of 1681ha. Soil maps, in semi detail scale, was the digital cartographic base used. The results allowed to conclude that 42.41% of the basin presented a good aptitude for farming in handling level of high technology (handling level C), regular aptitude for B, and restricted aptitude for A [class 1(a)bC] and that 12% of the area had regular aptitude for farming in the three handling levels (class 1abc). The watershed lands (14.24%) presented regular aptitude for farming in handling level C, restricted aptitude for B, and inapt for A [class of aptitude 2(b)c]; 15.85% presented good aptitude for planted pasture (class 4P) and 12.21% were considered without aptitude for agricultural use (class 6). We can say that 71.94% of the lands has aptitude for farming, although they present different degrees of limitations that request different treatments for its conservation.

Producción campesina de Honduras en rubros de exportación agrícola

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Os Répteis do Município de São Paulo: Diversidade e ecologia da fauna pretérita e atual

The reptile fauna in the municipality of São Paulo is well sampled due to intensive collection in the last 100 years. In the present work we provide a checklist of reptile species in São Paulo municipality based on preserved specimens in scientific collections. The reptile fauna was also characterized by three ecological parameters: habitat use, substrate use, and diet. We recorded a total of 97 reptile species (two turtles, one crocodilian, 19 lizards, seven amphisbaenians, and 68 snakes). Approximately 70% of the lizards and 40% of the snakes are typical of forest habitats of the Serra do Mar mountain range. Other squamates are typical of open formations that occur mainly on inland Cerrado habitats. All turtles and the crocodilian are associated to riparian habitats. Approximately 63% of the lizards are predominantly terrestrial, and the remaining species are arboreal. Most species of snakes are terrestrial (38%) or subterranean/criptozoic (25%) whereas a smaller proportion are arboreal (18%) or aquatic (9%). Lizards feed upon arthropods. Almost 50% of the snake species are specialized or feed mainly upon anuran amphibians. Other important items consumed by snakes are mammals (24%), lizards (18%), subterranean vertebrates (10%), and invertebrates (earthworms, mollusks and arthropods; 15%). A total of 51 reptile species have not been recorded for the last six years. Probably many of these species are extinct in the region due the intense local urbanization and habitat loss. The survey of species collected in São Paulo municipality and received in the Instituto Butantan in recent years allowed the identification of 10 lizards at least 42 snake species already occurring in the region. The high species richness of the original fauna seems related to the geographic location of the municipality, in a contact zone between forested areas of the Atlantic Forest (ombrophilous forest) and open formations (savannas, high-altitude grassland). Thus, the original habitat composition probably allowed sympatry among different species pools typical of both open and forested formations. The extant snake fauna recorded in the last three years indicates a higher loss of the species in open formations when compared to the forested areas.

Avances en la interpretación ambiental del desarrollo agrícola de América Latina

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Desarrollo agrícola y perspectiva ambiental en la Cordillera de la Costa chilena

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Entre el ideario y la realidad: capital social y desarrollo agrícola, apuntes para la reflexión

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Innovación y estructura productiva: la aplicación de biotecnología en la producción agrícola pampeana argentina

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Desarrollo agrícola y participación campesina

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El Estado en el desarrollo agrícola y las transformaciones rurales

Estudia los grados, tipos y funciones de la intervención del Estado en el desarrollo rural latinoamericano, así como sus relaciones con los grupos sociales.