Marcelo Ricardo de Lima

Rendimento de grãos de milho e soja em uma sucessão cultural de oito anos sob diferentes sistemas de manejo de solo e de culturas

To establish a rational and sustainable use of the soil it is necessary to know the effect of different tillage systems on production considering that this factor is directly related to its choice. The present experiment had the objective to evaluate the grain yield under different soil tillage systems after eight years. The experiment was carried out in an oxisoil, in Ponta Grossa - PR, Brazil. The treatments were: no tillage, conventional tillage (one plow and two light disking), minimum tillage (two light diskings), and no tillage with chisel tillage every three years. The experiment was arranged in randomized blocks with three replications. The tillage systems did not affect the grain yield of corn. In 1998, the grain yield of soybean showed that conventional tillage and minimum tillage were significantly higher than no tillage. However, in 2000, the soybean cultivar was replaced by BRS 133, and grain yield was significantly lower in conventional tillage and minimum tillage than no tillage.

O solo no ensino de ciências no nível fundamental

Soil is a component of natural and anthropogenic environments. Despite of its importance, the subject of soil is not usually taught in depth in the elementary school. This paper seeks to show the problems in teaching soil at the elementary school as well as to suggest alternatives to reduce these problems. The role of universities in this process is discussed, emphasizing the aspects related to graduate courses. Also the use of other strategies is discussed like: short courses, didactic books, experiments, exhibitions, and the use of internet.

Identificação e descrição de classes etnopedológicas de terras e atributos com agricultores familiares de Antonina e Morretes – PR

Este trabalho teve como objetivo identificar e descrever os conhecimentos etnopedologicos relacionados a classificacao de terras agricolas com agricultores familiares dos municipios de Antonina e Morretes - PR. A selecao do grupo informante ocorreu conforme a disponibilidade dos individuos em participar da pesquisa, sendo entrevistados 20 agricultores familiares, juntamente com seu grupo familiar. O conhecimento etnopedologico dos agricultores foi identificado e descrito atraves de diagnostico participativo que consistiu em quatro etapas: 1) entrevistas narrativas; 2) elaboracao de mapas participativos; 3) caminhadas na propriedade rural; 4) reuniao geral. Os resultados mostraram que os agricultores reconhecem e classificam os diferentes tipos de terras existentes nas unidades de exploracao agricola locais, sendo identificadas e descritas quatro classes: 1) “Terra de Morro”, 2) “Sabao de Caboclo”, 3) “Terra Argilosa” e 4) “Terra de Desmonte”. Os atributos empregados para a classificacao das terras mencionadas seguiram a sequencia: posicao na paisagem, textura, cor, drenagem, fertilidade e conteudo de materia orgânica. O sistema de classificacao dos agricultores entrevistados possibilita identificar e descrever de forma objetiva as terras, utilizando atributos e relacionando-os com aspectos cognosciveis, como aptidao agricola e manejo do solo.