Soil management qualification under no-till system in Center Southern Brazil.

No-tillage (NT) system comprises a set of technological processes aimed at exploring farming systems while promoting soil conservation management. Its main principles are: leaving soil undisturbed except for seeding in the drills or rows, the maintenance of permanent soil cover, the diversifi cation of crops by rotation or crop consortium, the adoption of joined harvesting-seeding process to reduce the time gap between operations. Although the NT system was developed to reduce erosion and to promote soil quality, there are several inadequate practices that have been applied in areas where cropping is misnamed as "No-tillage" system, e.g., the use of monoculture, the terraces misuse or elimination, the absence of contour plowing and others that are incompatible with the conservation principles and that lead to losses in soil and water quality and in local biodiversity. In order to improve the soil management in NT areas, a network research program coordinated by Embrapa Soils and supported by Itaipu Binacional has been studying no-tillage in twelve watersheds of six regions in Center-Southern Brazil since 2014. The network is developing indicators to assess soil management and its environmental eff ects at property and watershed scales. The program includes: participatory processes of self-evaluation, adjustment and certification by farmers; monitoring farming systems and small watersheds parameters (soil and plant) in twelve locations; long term experiments in six study-sites; and technology transfer in reference areas for training in NT systems. As preliminary results, the selection of monitoring watersheds has been carried out and the communication process has promoted eff ective participation of farmers in Paranapanema-SP, Londrina-PR, Toledo- PR, Maracaju-MS, Rio Verde-GO and Passo Fundo-RS. In addition, the establishment of local and international institutions network started up actions to improve soil management though no-tillage system.The monitoring approach adopts complementary methods to assess the farming system: IQP which is the No Tillage Participatory Quality Index developed by the Brazilian Federation of No-Till Farms and Irrigation (FEBRAPDP); DRES (Rapid Diagnostic of Soil Structure) to asses management structural quality in areas under NT; and Beta (β) index to classify watershed management based on hydrometeorological data, turbidity time series and sedimentary data set from monitored watersheds

Redução da dose do inseticida fipronil aplicada em sementes de arroz para o controle da bicheira-da-raiz.

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Corn yield for silage and grains in different integrated crop-livestock systems.

O objetivo do presente trabalho foi avaliar o efeito de duas doses de adubação nitrogenada (90 e 180 kg de N ha-1, aplicadas na pastagem de inverno), dois sistemas integrados de produção agropecuária (SIPA, com e sem árvores) e cinco posições entre renques arbóreos na qualidade e na produtividade do milho (Zea mays L.) para silagem e grãos. Os tratamentos foram investigados em um delineamento em blocos completos casualizados, com três repetições. As árvores foram plantadas em 2006 num arranjo de 14 x 3 m (atualmente com 158 árvores ha-1), em 6 das 12 parcelas. Ambos SIPAs foram conduzidos com milho durante o verão 2013/2014 e com gado de corte em pastagem anual durante o inverno anterior. O milho foi colhido para silagem no estádio fenológico R5 e para grãos aos 176 dias após a semeadura. As amostras para silagem foram trituradas e armazenadas em mini silos de PVC. Pequenas variações foram observadas na qualidade da silagem em relação a posição entre renques arbóreos. Diferenças entre doses de N no teor em matéria seca, proteína bruta (PB) e produtividade em grãos evidenciam o efeito residual da adubação de inverno. A associação com árvores proporcionou a colheita de uma silagem de melhor qualidade (menor teor de fibra em detergente ácido e maior teor em PB), mas reduziu em 52% a produtividade do milho colhido tanto para silagem como para grãos. Possíveis estratégias são discutidas para reduzir tais perdas

Evaluation of soil temperature effect on herbicide leaching potential into groundwater in the brazilian cerrado.

The effect of annual variations in the daily average soil temperatures, at different depths, on the calculation of pesticide leaching potential indices is presented. This index can be applied to assess the risk of groundwater contamination by a pesticide. It considers the effects of water table depth, daily recharge net rate, pesticide sorption coefficient, and degradation rate of the pesticide in the soil. The leaching potential index is frequently used as a screening indicator in pesticide groundwater contamination studies, and the temperature effect involved in its calculation is usually not considered. It is well known that soil temperature affects pesticide degradation rates, air-water partition coefficient, and water-soil partition coefficient. These three parameters are components of the attenuation and retardation factors, as well as the leaching potential index, and contribute to determine pesticide behavior in the environment. The Arrhenius, van't Hoff, and Clausius-Clapeyron equations were used in this work to estimate the soil temperature effect on pesticide degradation rate, air-water partition coefficient, and water--soil partition coefficient, respectively. The relationship between leaching potential index and soil temperature at different depths is presented and aids in the understanding of how potential pesticide groundwater contamination varies on different climatic conditions. Numerical results will be presented for 31 herbicides known to be used in corn and soybean crops grown on the municipality of São Gabriel do Oeste, Mato Grosso do Sul State, Brazil

Monitoramento de agrotóxicos e micotoxinas em grãos de arroz produzidos em áreas piloto da produção integrada de arroz irrigado na fronteira oeste do Rio Grande do Sul.

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