Structural sustainability of cambisol under different land use system

Abstract

SUMMARYIncongruous management techniques have been associated with some significant loss of agricultural land to degradation in many parts of the world. Land degradation results in the alteration of physical, chemical and biological properties of the soil, thereby posing a serious threat to sustainable agricultural development. In this study, our objective is to evaluate the changes in a Cambisol structure under six land use systems using the load bearing capacity model. Sampling was conducted in Amazonas Region, Brazil, in the following land use: a) young secondary forest; b) old secondary forest; c) forest; d) pasture; e) cropping, and f) agroforestry. To obtain the load bearing capacity models the undisturbed soil samples were collected in those land use systems and subjected to the uniaxial compression test. These models were used to evaluate which land use system preserved or degraded the Cambisol structure. The results of the bulk density and total porosity of the soil samples were not adequate to quantify structural degradation in Cambisol. Using the forest topsoil level (0-0.03 m) as a reference, it was observed that pasture land use system was most severe in the degradation of the soil structure while the structure were most preserved under old secondary forest, cropping system and forest. At the subsoil level (0.10-0.13 m depth), the soil structure was most degraded in the cropping land use system while it was most preserved in young secondary forest and pasture. At the 0.20-0.23 m depth, soil structure degradation was most severe in the old secondary forest system and well preserved in young secondary forest, cropping and agroforestry.Index terms: structure degradation, bulk density, precompression stress, Amazonas.(

Contact pressures and the impact of farm equipment on Latosol with the presence and absence of sugarcane straw

“…Dias Junior and Pierce (1995) pointed out that not every variation in the bulk density and, therefore in total porosity could be considered as degradation of soil structure, this is because the deformations in the secondary compression curve are elastic and recoverable, which, according to this author are variations inadequate to characterize the degradation of soil structure. Similarly, Martins et al (2012) assessing soil structural degradation, also found no changes in values of density and total porosity of the soil in the evaluation of various uses of the soil in the Amazon. It is noted that, in some cases, the evaluation of attributes as density and total porosity of the soil alone are not sensitive enough to research and breakdown the impact of agricultural traffic.…”

Propriedades físicas de Latossolos cultivados com cafeeiro mecanizado na região do Alto Paranaíba-MG

“…Mesmo padrão evidenciou-se na área BA14 na camada 0,1-0,2 m. Para a área AR17 não houve diferenças significativas (p<0,05) entre os valores de PT nas posições avaliadas em nenhuma das profundidades. Esses resultados indicam que esse atributo não foi apropriado para quantificar e avaliar o efeito do manejo da cultura sobre a estrutura do solo (MARTINS et al, 2012b), o que provavelmente pode ser devido ao fato do curto tempo de estabelecimento da cultivar nessa área (Tabela 1). A área AR17 foi instalada em novembro de 2017, cerca de 3,5 anos antes da coleta das amostras de solo.…”

Qualidade do solo em cultivos com plantas de cobertura no Alto Paranaíba-MG

“…A compactação é representada pelo aumento da densidade e da resistência do solo à penetração (LUCIANO et al, 2012;LOPES et al, 2020), e pode ser facilitada pela quantidade de água no solo. A água funciona como um lubrificante entre as partículas do solo, fazendo com que o mesmo se torne mais susceptível à compactação com o aumento de sua presença (MARTINS et al, 2012). Outra característica relevante para a compactação do solo é a sua textura.…”