Navegando por Autor "Silva, Marx Leandro Naves"

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Erosão hídrica em latossolo vermelho sob diversos sistemas de manejo do cafeeiro no Sul de Minas Gerais
(Editora UFLA, 2007-11) Carvalho, Ricardo; Silva, Marx Leandro Naves; Avanzil, Junior Cesar; Curi, Nilton; Souza, Fabiana Silva de
A erosão hídrica contribui para a redução da sustentabilidade dos sistemas agrícolas. O presente estudo avaliou, sob condições de chuva natural, as perdas de solo, água, nutrientes e matéria orgânica em um Latossolo Vermelho distroférrico típico, com 12 % de declividade, localizado na região de Lavras (MG). O trabalho foi conduzido em parcelas experimentais de perdas de solo. Os sistemas de manejo estudados foram: café sob cultivo convencional, com capina manual (CCC); cultivo convencional, com roçado (CCR); cultivo convencional, com utilização de herbicida (CCH); cultivo orgânico, com capina manual (COC); cultivo orgânico, com roçado (COR); e como referência parcela com solo descoberto (SD). Nos sistemas de manejo em que foi mantida a cobertura da vegetação espontânea (roçado), obteve-se maior eficiência de proteção do solo quando comparado aos sistemas onde houve exposição do solo (capina). No sistema com utilização de herbicida, observou-se um comportamento intermediário. Todos os sistemas de manejo estudados se mostraram conservacionistas quanto à proteção do solo em relação à erosão hídrica, onde o espaçamento adensado merece ser enfatizado.
Variações de curto prazo nas emissões de CO2 do solo em diferentes sistemas de manejo do cafeeiro
(Sociedade Brasileira de Química, 2009) D’Andréa, Alexandre Fonseca; Silva, Marx Leandro Naves; Curi, Nilton; Freitas, Diego Antonio França de; Roscoe, Renato; Guimarães, Paulo Tácito Gontijo
Soil CO2 emissions represent an important component of carbon global cycle. However, information about short-term alterations of CO2 fluxes in soils of tropical regions are scarce. So, the objective of this study was to evaluate such variations in coffee plantations in Latosol (Oxisol). The CO2 emissions were not affected by environmental abiotic factors, such as temperature and soil water evaporation, but they were significantly correlated with the carbon content of microbial biomass (R=0.90, P<0.05). It happens a close relationship between root activity and soil CO2 emission in coffee plantations.
Water erosion in oxisols under coffee cultivation
(Sociedade Brasileira de Ciência do Solo, 2018) Mendes Júnior, Henrique; Tavares, André Silva; Santos, Walbert Júnior Reis dos; Silva, Marx Leandro Naves; Santos, Breno Régis; Mincato, Ronaldo Luiz
Water erosion is one of the main environmental impacts of land use. When soil and water losses occur, nutrients essential for the growth and maintenance of plants are removed, with harmful outcomes on the sustainability of agriculture and the environment. In addition, they lead to other deleterious effects, such as sedimentation and eutrophication of water bodies. Estimation of soil losses due to water erosion in sub-basins is essential for prediction of soil degradation, especially in areas of semi-intensive cultivation, such as coffee fields. Thus, the aim of this study was to estimate soil losses in relation to the limit of soil loss tolerance in Oxisols (Latossolos Vermelhos Distróficos) under coffee cultivation. This study was conducted from March 2015 to January 2017 in the Córrego da Laje Hydrographic Sub-basin in the municipality of Alfenas in the southern region of Minas Gerais, southeastern Brazil. Soil losses due to water erosion were estimated from the revised universal soil loss equation and compared to soil loss tolerance. Morphological, physical, and chemical properties of the soil were used, as well as geoprocessing techniques, remote-sensing images, and data from the literature. The results show potential soil losses from 0.01 to 18.77 Mg ha -1 yr -1 , with an average of 1.52 Mg ha -1 yr -1 . The soil loss tolerance ranged from 5.19 to 5.90 Mg ha -1 yr -1 , with 7.35 % of the area having larger losses. Areas with steeper slopes and no sustainable practices have soil losses above the tolerance level and are thus a priority for adoption of measures to mitigate erosive effects. The revised universal soil loss equation enabled water erosion modeling and identification of areas with the highest rates of potential soil loss in watersheds.