Luciene Kazue Tokura

Structural Alterations of Paraná’s Oxisols by Cover Crops

This work aimed to evaluate the dynamics of physical and hydric attributes of a clayey Latosol cultivated with different cover species. The experimental area was located in the Agronomic Institute of Parana (IAPAR), in the regional hub of Santa Tereza do Oeste, Parana, Brazil. The experiment was comprised of seven cover species also called treatments is the course of this work. Three of them were isolated summer species notably Crotalaria juncea, Crotalaria spectabilis, Cajanus cajan (pigeon pea), and the other four treatments winter species cultivated individually or in association including Avena strigosa (Black oat), + (Avena stirgosa + Raphamus sativus (radish), Avena strigosa + Lupinus albus (Lupin bean), and (Avena strigosa + Pisum sativum (pea). The treatments were distributed on a completely random plots of 20 m × 25 m without replication. Soil density, macroporosity, and saturated hydraulic conductivity were measured to follow the changes of the soil structure. Statistical analyses showed that cover crops species did not lead to a significant improvement in soil structural status. Soil density varied between 1.08 and 1.12 Mg m-3, macroporosity from 15.22 and 16.90%, and saturated hydraulic conductivity ranged from 28.83 to 45.07 mm h-1. Soybean grain yield were considered satisfactory in 2016 (mean = 1909.68 kg ha-1) and in 2017 (mean = 3355.30 kg ha-1) most probably due to the good initial structural conditions of the soil, alongside with the good climatic conditions during the two campaigns. Furthermore, the soybean grain yield was positively influenced by Ds which ranged from 1.0 to 1.17 Mg m-3.

Effect of Hydroxy (HHO) Gas Injection in a Gasoline Electric Generator for Rural Areas

This study aimed to evaluate how the HHO gas injection from an electrolyser, conventional bipolar type, works inside a motor-generator fueled with gasoline for utilization in rural areas. After the injection of HHO gas together with gasoline, the parameters of exhaust gases, exhaust temperature, pollution expelled, specific consumption of the engine and excess air, were checked and compared. The main results allowed the evaluation of the engine, when it was fueled with gasoline and HHO gas, which had a better performance than that when fed only with gasoline. The results showed that the engine consume less gasoline and generate fewer pollutant gases when in operation with the injection of HHO gas without the need of radical changes in the engine design.

Economic Viability of Photovoltaic Systems in a Rural Community in Brazil

Solar energy can be converted directly into electricity using photovoltaic cell technology. It is considered as the technology of the future because it uses the Sun, a clean and inexhaustible source. Thus, this study aimed to evaluate the economic viability in energy generation of a photovoltaic system in a rural community in the district of Rio do Salto. The rural community is in the municipality of Cascavel, western region of the state of Parana, geographical coordinates latitude 25°831S, longitude 53°1940W and altitude 781 m. Rio do Salto has regulations of 19 blocks with 241 properties. The evaluated properties belonged to block 11. The project was feasible when the payback period of the investment occurred within the expected photovoltaic system life cycle and if the internal rate of return (IRR) was higher than the minimum attractiveness expected for the project. To ensure the viability of this power generation system, the average consumption over the 12-month period should be higher than the rate of availability of the concessionaire that the owner should pay. This value varied according to the connection type (single-phase: 30 kWh, two-phase: 50 kWh and three-phase: 100 kWh). Property 9 was the only one that did not show conditions for photovoltaic system for not reaching the minimum connection tariff of the concessionaire.

Dynamic of Phosphorus Fractions in Typic Quartzipsamment Soil Cropped With Bean

Phosphorus is the most limited nutrient in Brazilian soils for plant growth, resulted of low availability and poor P content in bedrock. The aim of the study was to evaluate the dynamic of P fractions in a sand soil typical Quartzipsamment cropped with common bean under the effects of P and Si-fertilizer rates. The research was carried out in a soil with sand texture and clay mineralogy constituted mainly by kaolinite, classified as Neossolo Quartzarênico Órtico típico (RQo). The greenhouse location was the campus of Universidade Federal de Lavras located in the city of Lavras, state of Minas Gerais, Brazil (approximately 21°13′46.54′′ S and 44°58′26.30′′ W, average altitude 932 m above sea level). The experimental design used was entirely random, arranged in a 4 × 3 factorial design, with four repetitions, with amount of 48 experimental units. The treatments included four P rates (0, 80, 240 and 410 mg dm) and four Si rates (0, 240 and 410 mg dm). Phosphorus fractions in soil are little affected by Si-fertilizer rates. P uptakes by bean plants are correlated to the labile and moderately labile fractions. P-fertilizer rates increment majority the stable P fraction in soil and in lower proportion the labile and moderately labile P fractions in soil. Po-NaHCO3 is the only that contributes to bean plant nutrition.

Efeito residual da aplicação de silicato de cálcio nos atributos químicos do solo e na produtividade da cana-soca

Trabalhos de pesquisa no Brasil e em outros paises, com a utilizacao de silicato de calcio, vem mostrando resultados promissores na cultura da cana- de- acucar. Este trabalho objetivou avaliar o efeito residual da aplicacao do silicato de calcio como material corretivo de acidez do solo, nos atributos quimicos do solo e na produtividade da primeira soqueira de cana-de-acucar. O trabalho foi desenvolvido, em condicoes de campo, na Fazenda Escola da Anhanguera de Dourados-MS, com a variedade SB803250. O delineamento experimental utilizado foi em blocos casualizados, com quatro repeticoes. Os tratamentos foram constituidos de doses distintas de silicato de calcio (0, 700, 1400, 2800, 5600 kg ha -1 ). No solo, a amostragem foi realizada aos 24 meses apos a aplicacao do silicato de calcio, nas camadas de 0-0,2- e 0,20-0,40 m de profundidade, determinando os atributos quimicos para fins de fertilidade do solo e a produtividade da cana-soca. O silicato de calcio promoveu efeito residual benefico nos atributos de acidez do solo apos 24 meses da aplicacao. A aplicacao do silicato de calcio, em pre-plantio, promoveu efeito residual positivo na produtividade da soqueira da cana-de-acucar.

Efectos alelopáticos del extracto acuoso de hojas de frijol canavalia sobre el cultivo de cártamo

This study verified the allelopathic influence of jack bean leaves ( Canavalia ensiformis ) on safflower cultures ( Carthamus tinctorius ), applied at different concentrations. Ten safflower genotypes were seeded in 20 containers, and a concentrate was prepared with jack bean leaves, crushed with water to make the extract. Five treatments were performed with four replicates, and this extract was applied at concentrations of 0%, 25%, 50%, 75% and 100%. The parameters were germination speed, percentage of germination, dry and fresh mass, leaf and root size. The jack beans influenced each evaluated treatment differently, presenting, at some times, neutral characteristics, inhibitory characteristics, or stimulating characteristics, varying according to the percentage of extract that was applied.