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Terramechanic evaluation of the root growth in an ultisol soil of savanna of the Monagas State of Venezuela
Titel:
Terramechanic evaluation of the root growth in an ultisol soil of savanna of the Monagas State of Venezuela
Auteur:
Américo J. HOSSNE G.
Verschenen in:
Revista científica UDO agrícola
Paginering:
Jaargang 4 (2004) nr. 1 pagina's 42-52
Jaar:
2004
Inhoud:
It is a widespread concept that the apparent densities (ρN, ρS) of the soil are index of radical growth when considering thatthe roots grow through the interparticle spaces and that the compacted soil, without comparative reference of the soilhumidity, offer resistance. This has borne to consider that the primordial impediment in the radical development is soilcompaction. The mechanical soil indexes are few or hardly ever mentioned for the agricultural soils, unless it is a questionof soil traction. The general objective is based on evaluating the mechanical and physical conditions of the savanna soilswith the purpose of producing contributing information to clarify the process of the radical growth. The specific objectivesconsisted in: (a) to relate the efforts exercised by the roots developed in their growth and the mechanical resistance of thestudied soil and (b) to evaluate the physical and mechanical conditions of the soil and their influence in the radicaldevelopment. The methodology was based on the methods of Soil Mechanics and Soil Physics to evaluate some physicalindexes, the Apparatus Triaxial to evaluate the shear tension τ and the evaluation of the efforts versus soil resistance in theprocess of radical growth obtained bibliographically. The regression analysis was used to interpret the variance among theparameters. Among the results: (1) the soil shear tension was established, (2) comparative values of the axial loads of theroots and soil resistances that inhibit its growth with the values of the shear tension τ as a function of the soil humidity (w),the limits of consistency and the field capacity, and (3) the importance of some textural components and organic matter. It isconcluded: (a) the soil humidity influences radical penetrability, which diminishes the actions of the physical andterramechanic parameters resistance; (b) the root grows, according to the area section, through the soil where there is smaller resistance, or shearing the soil where the radical axial tension is at least bigger to the soil resistance where the soilmasses possibly collapse one in front of the other or that the radial growth produces lateral opening favoring the radialgrowth, and (c) the root growth action increases its axial tension when increasing the soil resistance with a critical value of2,343.2 kPa for 20.78% of growth. These soils exercised a resistance minor to the 0.5 MPa in the range of the field capacity.
Uitgever:
Universidad de Oriente Press (provided by DOAJ)
Bronbestand:
Elektronische Wetenschappelijke Tijdschriften
Details van artikel 180 van 185 gevonden artikelen
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