Soil shear strength under non-irrigated and irrigated short duration grazing systems

Revista Brasileira de Ciência do Solo

Rita De Cássia Ribeiro Carvalho²  Wellington Willian Rocha¹  José Cardoso Pinto¹  Bruno Da Silva Pires¹  Moacir De Souza Dias Junior¹  Ayeska Hubner Braga Nunes¹ 

[1] ,Estate University of Minas Gerais

关键词: Soil compaction;    pasture;    animal trampling;    compactação do solo;    pastagem;    pisoteio animal;   

DOI  :  10.1590/S0100-06832010000300004

来源: SciELO

【 摘 要 】

Pasture productivity can drop due to soil compaction caused by animal trampling. Physical and mechanical alterations are therefore extremely important indicators for pasture management. The objective of this research was to: draw and evaluate the Mohr failure line of a Red Yellow Latossol under different pasture cycles and natural forest; calculate apparent cohesion; observe possible physical alterations in this soil; and propose a correction factor for stocking rates based on shear strength properties. This study was conducted between March/2006 and March/2007 on the Experimental Farm of Fundação de Ensino Superior de Passos, in Passos, state of Minas Gerais. The total study area covered 6 ha, of which 2 ha were irrigated pasture, 2 ha non-irrigated pasture and 2 ha natural forest. Brachiaria brizantha cv. MG-5 Vitória was used as forage plant. The pasture area was divided into paddocks. The Mohr failure line of samples of a Red Yellow Latossol under irrigated pasture equilibrated at a tension of water content of 6 kPa indicated higher shear strength than under non-irrigated pasture. The shear strength under irrigated pasture and natural forest was higher than under non-irrigated pasture. At a tension of water content of 33 kPa no difference was found in shear strength between management and use. Possible changes in soil structure were caused by apparent cohesion. The values of the correction factor were close to 1, which may indicate a possible soil compaction in prolonged periods of management.

【 授权许可】

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