ABSTRACT
In the area of expansion, where if you have restriction on fertility, soil preparation has contributed considerably to the improvement of the physical, chemical and water conditions of soils and, consequently, to the proper development of culture of sugarcane. The aim of this study was to evaluate the effect of different management techniques on the availability of nutrients in soil in an area of expansion of sugarcane, formerly with Brachiaria decumbens, in the Cerrado region. The experiment was conducted using the CTC 2 variety at Jalles Machado mill in Goianésia, GO. The experiment was established in a randomized block design, with six treatments and four replications. Chemical attributes of soil were evaluated at depths of 0-20, 20-40 and 40-60 cm. Significant differences were found among depths for all analyzed attributes. Adopted management systems influenced chemical attributes and the availability of nutrients for plants. Invertion of soil through plowing and harrowing is extremely beneficial to carry out soil amendment in the first year of cultivation, improving the incorporation and effectiveness of the corrective. The adoption of no-tillage system did not prove to be the best option for the first year of sugarcane cultivation, hindering the incorporation of the corrective.
Em área de expansão, onde se têm restrições quanto à fertilidade, o preparo do solo contribui consideravelmente para a melhoria das condições físicas, químicas e hídricas dos solos e, consequentemente, para o desenvolvimento adequado da cultura da cana-de-açúcar. O objetivo deste trabalho foi avaliar o efeito de diferentes técnicas de manejo, sobre a disponibilidade de nutrientes no solo, em área de expansão de cana-de-açúcar, anteriormente com a presença de Brachiaria decumbens, na região do cerrado. O experimento foi conduzido na usina Jalles Machado, em Goianésia, GO, sendo utilizada a variedade CTC 2. O experimento foi implantado em delineamento de blocos casualizados, com seis tratamentos e quatro repetições. Foram avaliados os atributos químicos do solo, nas profundidades de 0-20, 20-40 e 40-60 cm. Foram observadas diferenças significativas entre as profundidades para todos os atributos analisados. Os diferentes manejos adotados interferiram nos atributos químicos e na disponibilidade de nutrientes para as plantas. O revolvimento do solo através de aração e gradagem é extremamente benéfico para a realização da correção do solo para o primeiro ano de cultivo, tornando melhores a incorporação e eficácia do corretivo. A adoção do sistema plantio direto não demonstrou ser a melhor opção para o primeiro ano de cultivo de cana-de-açúcar, dificultando a incorporação dos corretivos utilizados.
Subject(s)
Land Use , Soil Characteristics , Food , SaccharumABSTRACT
Background & objectives: Sleep restriction is a common feature of modern lifestyle and its effects can be extended to pregnancy. Several neurobehavioural consequences of sleep restriction during pregnancy have been reported, among which stand out perinatal depression and maternal fatigue, however, its effects over mother-infant relationship warrant further investigation. Thus, this study was aimed to evaluate the effects of sleep restriction during pregnancy over maternal behaviour and maternal aggression through animal models. Methods: Eighteen 90-day-old female Wistar rats were distributed in two groups: (i) Control - not submitted to any manipulation during pregnancy, and (ii) Sleep restriction - submitted to sleep restriction during the entire pregnancy (21 days) through the multiple platforms technique. In the postpartum day 5, resident-intruder paradigm and the latencies test were performed to assess both maternal behaviour and maternal aggression. Results: The sleep-restricted females displayed grooming in less frequency and duration, and with higher latency when compared to normal animals, while maternal aggression and maternal behaviour parameters remained equivalent between groups. Interpretation & conclusions: Considering the maintenance of maternal behavioural parameters, the inhibition of grooming seems to exert an adaptive mechanism, enabling sleep-restricted rats to display maternal behaviour properly.