Emerson Fey

Profundidade e espaçamento da mandioca no plantio direto na palha

The experiment was conducted in eutrophic Oxisol soil in Marechal Cândido Rondon, PR, Brazil. It consisted of planting cassava in a factorial design. Factors included two row design: simple (1.00 x 0.60m), double rank (1.50 x 0.50 x 0.60m); and three planting depths (0.05, 0.10 and 0.15m). Planting was accomplished in no-tillage system over oat straw. Measured variables 17 months after planting included: stalk mean diameter; damping-off index; resistence to manual harvesting; root starch concentration; and productivity of root and starch. The results indicated that damping-off index was lower at 0.15m planting depth. However, cassava planted at the 0.15m depth demanded the higest labor for harvesting and the lowest root and starch productivities. The best root and starch productivity was achiered at the 0.10m soil depth.

Distribuição de palha por colhedoras autopropelidas na colheita da soja

The difficulty of getting a uniform residues distribution, in the width of the combine cutting ban, have been observed in crop fields. The objective of this work was to evaluate the uniformity of straw distribution for combines harvesting soybean. It was appraised nine combines in the operation conditions and adjustment that they were being used by the operator. The Coefficient of Variation (CV) was used for comparison of the machines and the evaluation of the distribution uniformity, and had accomplished a multivariate analysis to evaluate the similarity among the combines in function of the coefficient of variation, humidity of the straw and width of the cut platform. All the combines had presented a disuniform straw distribution, resulting in bands, with raised straw concentration in the combine central part and little in the extremities, independently of the width of the cut platform. But a combine presented distribution next to the ideal, for also possessing a delivering system for the straw proceeding from the bolters. One evidenced that the deriving straw of the combine bolters can be the responsible for the formation of bands with raised amounts of straw in the combine center, independently of the machine size.

Variáveis dimensionais de sementes de soja que influenciam o processo de semeadura

In the soybean seeding (Glycine max (L.) Merrill) process, the commonly used seed drill is assembled with the perforated horizontal plate type seed metering mechanism. To accomplish an efficient seeding process, using metering device parameters such as speed and seed homogeneity should be considered. The objective of this research was to study the influence of the soybean seed dimensional variables on quality of seed drill. For the purpose, a precision seed drill with four horizontal dosing plates and three soybean cultivars were used along with five speeds. The dependent variables were percentage of disc cells filling and percentage of the physical damage to seed. The best subsets method, is Minitab software, which adjusted well to experimental data. It was concluded that speed; seed size, coefficient of variation and the difference between seed size (length and width) and plate cells influenced the disc cell filling.

Mobilidade de íons em solo sob sistema de semeadura direta submetido às adubações mineral e orgânica

A retencao, no perfil do solo, de elementos minerais aplicados em sua superficie e fundamental para manter a qualidade da agua e diminuir prejuizos economicos e ambientais. Este trabalho avaliou a mobilidade do K, Ca, Mg, teores de Al e materia orgânica, as alteracoes de pH, em Latossolo Vermelho eutroferrico cultivado sob sistema de semeadura direta, bem como a demanda quimica de oxigenio (DQO) da agua de percolacao. A mobilidade foi medida em colunas de solo com estrutura preservada e submetidas a adubacao mineral (100 kg ha-1) ou orgânica (150 m3 ha-1). Com uso de adubo mineral houve maior lixiviacao de K, Ca e Mg, mesmo com maior quantidade de K aplicado via adubo orgânico do que via adubo mineral. A DQO da agua percolada no sistema com adubacao orgânica foi menor do que com adubacao mineral. Os teores de Ca2+ e de Mg2+ foram maiores na camada de 0 a 2,5 cm, principalmente para a adubacao orgânica. O adubo orgânico nao aumentou o teor de materia orgânica no solo, porem, na camada de 0 a 2,5 cm, elevou o pH do solo em uma unidade e neutralizou o Al3+. Os resultados deste trabalho mostram o efeito depurador do solo sobre aguas contaminadas, evidenciando os beneficios economicos e ambientais que poderao advir com a infiltracao no solo da agua de enxurrada que venha a se formar em lavouras.

Perda de nutrientes via escoamento superficial no sistema plantio direto sob adubação mineral e orgânica

The no-tillage system, has contributed to improvements in agricultural soils, among them the like increases in nutrient concentrations.of mineral elements in soil. However, it has been found that this increase concentration occurs mainly in the first few centimeters of the superficial top layer and so risks of nutrient losses by runoff, and associated of the soil, which concurs for losses of mineral elements through of runoff, with economic and environmental damages, are high. This study evaluated the total concentration, in runoff, of mineral elements potassium (K), calcium (Ca), magnesium (Mg) and copper (Cu) in total form and the soluble and particulate concentration form of K, in runoff caused to simulated rainfall of different intensitiesy applied over soil under no-till system and submitted to simulated after application of organic or mineral fertilizers in no-till soil. The fertilizers did not affect the concentration of mineral elements studied nutrients in runoff, except in condition of more high intense rainfall and soil under after organic manure application, which promoted runoff with showed the higher highest concentration of soluble and total K. Independent Irrespective of the type of fertilizers utilized type, the rainfall of higher intensity resulted in higher concentrations of all the mineral elements and forms studied, either in total, soluble or particulate form, evidencing the economic and environmental benefices, risks and suggesting that with the adoption of practices for runoff contention of runoff practices must be adopted , even in tilled croplands areas managed under no-till system.