Abstract

MARTINEZ-RUBIN DE CELIS, E et al. Alfalfa (Medicago sativa L.) production in soil at different bulk densities under controlled conditions. Phyton (B. Aires) [online]. 2011, vol.80, n.2, pp.189-192. ISSN 1851-5657.

Soil compaction or increase of soil bulk density (Da) as a result of applied loads is expressed as an increase in soil bulk density and soil resistance to penetration. Factors in soil compaction due to vehicular traffic include: the amount of load, soil moisture content and the number of passes over the land. Soil compaction results in the formation of layers that can limit or delay (1) the aeration process; (2) root penetration and infiltration; (3) absorption capacity and soil water retention; (4) nutrient movement; (5) heat transfer, and (6) seedling emergency. At the same time, it will produce plants of lower height, uncommon leaf color and an increasing energy demand to work that soil. The purpose of this investigation was to determine the effect of soil compaction on alfalfa plants and their production under controlled conditions. Soil deposition in containers allowed the following Da treatments: 1.2 g/cm³; 1.35 g/cm³; 1.5 g/cm³ and 1.65 g/cm³. Five hundred and fifty alfalfa seeds variety "El Camino" were sown per m². The study variables were: emergency percentage, plant height, number of leaves, stem diameter and crop yield. Soil bulk density increases did not significantly change plant emergency, but reduced plant height (Ap) up to 40% with trend: Ap=63,12-27,06*Da. As Da increased, the number of leaves decreased up to 50%, stem diameter tended to increase, and either green or dry yield production was reduced up to 34% or 29.7%, respectively.

Keywords : Soil compaction; Forage production; Phenological stages; Medicago sativa.

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