O preparo do solo pode contribuir para a melhoria das condições físicas e químicas objetivando o adequado desenvolvimento da cultura da cana-de-açúcar. O objetivo foi avaliar a interferência de diversos tipos de preparo de solo e do plantio direto nas características agronômicas e produtividade da cana-de-açúcar em uma área de reforma. O experimento foi conduzido no município de Goianésia (GO) em um Latossolo Vermelho-Amarelo de textura média, utilizando-se a variedade IAC 87-3396. O delineamento experimental utilizado foi o de blocos casualizados com seis tratamentos e quatro repetições. Os tratamentos foram: T1) dessecação + calcário + aração + gradagem; T2) calcário + subsolador + gradagem; T3) dessecação + calcário + plantio direto; T4) dessecação + calcário + subsolador; T5) destruidor de soqueira + calcário + subsolagem; e, T6) destruidor de soqueira + calcário + grade + aração + grade. Foram avaliados o número, diâmetro, altura e a produtividade dos colmos. Os diferentes preparos de solo não influenciaram nas características agronômicas da cana-planta. O uso de arado de aiveca associado à grade na incorporação do calcário proporciona as maiores produtividades de colmo de cana-de-açúcar. O plantio direto mostrou-se alternativa viável ao cultivo da cana-de-açúcar, por apresentar produtividade de colmo semelhante aos demais preparos do solo.

New strategies for sugarcane production have been very important since the incorporation of ethanol in the Brazilian energy mix in the early 1970s. Prior to planting sugarcane, the soil is prepared, and this process can affect root development and, consequently, sugarcane production. This study was conducted in an area of sugarcane crop renewal in the Cerrado biome (Brazilian tropical savanna), with the objective of identifying which tillage system generates the better root development and improved yield in sugarcane. The treatments were: 1) weed desiccation + moldboard plowing (0.4 m) + mild spike tooth harrowing (0.15 m); 2) subsoiler (0.3 m) + mild spike tooth harrowing (0.15 m); 3) weed desiccation + no-tillage (furrow opening and fertilizer); 4) weed desiccation + subsoiler (0.4 m); 5) ratoon destruction + subsoiler (0.4 m); 6) ratoon destruction + spike tooth harrowing (0.2 m) + moldboard plowing (0.4 m) + mild spike tooth harrowing (0.15 m). Characteristics of the sugarcane root system, such as the root length density, average distance between roots, and root soil exploration, after the first harvest (1.5 years) were studied. Root length density was greater for the treatments that included plowing (0.4 m) and harrowing (0.15 m) operations. The average distance between roots was low in the no-tillage system. The highest sugarcane yield in the plant crop was achieved by management practices with more extensive soil profile disturbances, like plowing followed by harrowing.

ABSTRACT:The evaluation of technologies employed at the agricultural production system such as crop rotation and soil preparation, both associated with crop-livestock integration, is crucial. Therefore, the aim of the present study was to evaluate the incorporation of lime for three no-tillage systems and cultural managements in system of crop-livestock integration, with emphasis on corn grain yield. The experiment was conducted from January 2003 to April 2005 at Selvíria city, MS, in Dystroferric Red Latosol, clay texture. The experimental design was randomized blocks with split plots consisted of three main treatments, aimed the soil physics conditioning and the incorporation of lime: PD -No-no-tillage; CM -minimum no-tillage, and PC -conventional no-tillage; and of two secondary treatments related to the management: rotation and crop succession, with four replications. Data on agronomic traits of maize were analyzed: plant height, stem diameter, height of the first spike insertion, 100 grains weight and grain yield. The results showed that the maize produced under the system of croplivestock integration is quite feasible, showing that grain yields are comparable to averages in the region and the different soil physical conditioning and incorporation of lime did not influence the corn yield as well as the cultural managements, rotation and succession, did not affect the maize crop behavior after two years of cultivation.

Monitoring the physical quality of soils under intensive sugarcane production requires sustainable forms of use and soil management. Thus, the objective of this research was to evaluate the influence of soil tillage systems on soil porosity and density in ratoon-cane cultivation, in addition to possible changes which may occur during the season. The experiment was carried out in the state of Goiás, Brazil. The Experimental design was randomized blocks with four replications. The following tillage systems were evaluated: 1. Moldboard plow + Harrow; 2. Subsoiler + Harrow; 3. Direct planting; 4. Subsoiler + Direct planting; 5. Stubble thrasher + Subsoiler; 6. Stubble thrasher + Harrow + Moldboard plow + Harrow, in soil layers 0-0.2; 0.2-0.4 and 0.4-0.6 m. Regardless of the tillage system used during sugarcane cultivation, the ratoon crop showed reduced total soil pore volume and macroporosity, as well as increased soil density in the 0.4-0.6 m layer. However, the use of direct planting resulted in +higher soil macroporosity values in the 0-0.2 m layer and yields similar to conventional systems which use the moldboard plow. Therefore, it is recommended for producers to adopt conservation soil tillage systems, combining productivity and soil quality.

Práticas educativas podem motivar os alunos e influenciar na permanência escolar?  Este estudo tem como pressuposto que a maneira como se dão as práticas educativas e pedagógicas durante os processos de ensino aprendizagem contribuem para permanência do aluno na escola, apresentando a evasão também como consequência de práticas que interferem no processo de aprendizagem. A evasão no PROEJA, objeto de estudo abordada em trabalhos acadêmicos em forma de dissertação de mestrado, disponíveis na Biblioteca Digital de Teses e Dissertações contêm apontamentos que contribuem com a averiguação dessa hipótese, mas sem descartar o papel que o meio social exerce sobre esses indivíduos. Através desse recorte foi possível averiguar como esse problema foi abordado nessas pesquisas e a relação que se revelam com as Práticas Educativas, constatando-se que essa suposição é verdadeira, exigindo uma postura diferente das instituições e dos educadores desse programa, aperfeiçoando e adotando práticas educativas inovadoras e significativas que possam contribuir com maior engajamento dos estudantes, melhor aproveitamento na assimilação dos conteúdos abordados e também na contraposição da evasão escolar nessa modalidade.