Shear strength and compressibility of a Latosol under different uses and weed management / ResistÃncia ao cisalhamento e compressibilidade de um Latossolo sob diferentes usos e manejos.

AUTOR(ES)
DATA DE PUBLICAÇÃO

2007

RESUMO

Soil compaction has been pointed out as one of the main process of yield reduction of a number of farming activities. Amongst the affected activities, the ones that suffer the most from this problem are the ones that preserve the soil structure, namely, those which do not imply in having the annual soil tillage. Grasslands and no-tillage planting of maize fit into that reality, since, in most times, the plowing operations of soil in these activities occur as related to soil surface compaction, whether by animal trampling whether by machine traffic, without moisture control. The use of the load support capacity models to aid in preventing or in identifying the more resistant or susceptible managements to soil compaction is a tested and consolidated methodology. However, the shear strength of agricultural soils and its parameters can help and add to the methodologies used at present time. This study was carried out with the objectives of: a) generating load support capacity models for the different managements of a Red-Yellow Latosol; b) identifying through of the use of the load support capacity models the management more susceptible and more resistant to compaction; c) developing shear strength envelopes and obtaining its parameters for the different management systems of a Red-Yellow Latosol; d) comparing the shear strength envelopes and proposing a better soil use based on these managements. The study was conducted in the period of February of 2006 to February of 2007, in the town of Passos, MG, at latitude of 19ÂS and longitude 43ÂW from Greenwich. The areas of the study lie at an average altitude of 700 m, with annual average temperature of 19ÂC, annual average rainfall of 1,709, 4 mm and average slope of 6%. Seven managements in soil under study were evaluated, namely: (1) grasslands irrigated before animal trampling (2) grasslands irrigated after animal trampling (3) grasslands not-irrigated after animal trampling and (4) after animal trembling, access corridor to the enclosures (5) no tillage planting of corn (6), and native woodland (7). The unaisturbed soil samples were utilized in the uniaxial compression test and in the shearing strength trials. Texture, organic matter, field capacity and permanent wilting point were also determined. The management: irrigated and non-irrigated grassland, before animal trampling generated similar load support

ASSUNTO(S)

ciencia do solo

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