Antonino Terminiello

Compactación del suelo durante la cosecha forestal: evolución de las propiedades físicas

The long-term effects on soil compaction by different traffic intensities during forestry harvester operation were evaluated in field experiments on heavy clay, vertic Argiudol. A conventional 2WD 73.5 kW engine power tractor with a trailer, 4.2 Mg and 3.75 Mg total load respectively, were used on a multiclonal Populus deltoides (Marsh) 3x3 plantation. There were four treatments: one pass, five pass and ten repeated passes with the tandem over the same track, and a control plot without experimental traffic. Moisture content, bulk density and penetrometer resistances were evaluated before and immediately after the traffic treatments and three years later. Effects of induced soil compaction by traffic were especially marked on topsoil, with cone index increments between 76 and 16% in the first 40 cm of the surface layer after treatments. Bulk density had a similar tendency but limited to a 15 cm depth. Three years later, only subsoil cone index in the track line, below 20 cm depth, was significantly higher than the interline track soil cone index. The 10 passes treatment had significant differences compared to the 1 pass and no traffic control plot treatments from the surface layer to 50 cm depth, without differences with the 5 passes treatment in most of the studied soil layers. Subsoil compaction may be induced by repeated traffic with low axle load and their effects persist for a very long time.

Compactación inducida por el tránsito vehicular sobre un suelo en producción hortícola

Field test were carried out with the objective of characterizing the state of compaction in horticultural soil induced by traffic, after the development of a cabbage crop (Brassica oleracea L. group capitata) cycle, and its incidence on yield. Measurements of penetration resistance, bulk density, and moisture content in soil were made and aeread biomass at the end of the cycle crop in sectors with larger and smaller number of vehicles passes. Values of penetration resistance of 1.7 and 1.3 MPa were found for treatment with more than 7 passes and 3 passes respectively in the depth range of 0-100 mm. No significant differences were found in bulk density parameter in the entire soil profile. Statistically significant differences were found for aereal biomass values of 3 passes treatment (1902.6 g plant-1), in relation to more than 7 passes (1447.9 g plant-1). Repeated passes on rows resulted in increments of penetration resistance at shallow depths. The number of the tractor and agricultural machinery passes influenced the fresh and dry weight of crop.

Comportamento mecânico do solo sob tráfego em dois sistemas de preparo do solo

A former concern related to agricultural soil, under no tillage systems, might be the state of compaction due to farm machinary traffic. Two treatments corresponding to two different tillage systems (disk plowed, LC, and no tillage, SD) included four traffic subtreatmets (0; 80; 160, and 240 Mg km ha-1) on a Typic Hapludert. Cone index (IC) and dry bulk density (DA) were the experimental dependent variables asessed. Soil reology under traffic had a different behaviour in both treatments. In both treatments for the higher traffic intensities (160 and 240 Mg km ha-1) statistical significant difference (P < 0,05) were measured when compared with the control plots, when the IC was considered. Considering LC treatment and the higher traffic intensities, the dry bulk densities values measured arised to 1.83 Mg m-3, the disk plowed, and no tillage under traffic soils reologies are different. If the depth of the maximum response in terms of IC measurements is considered, a direct relationship between traffic intensities and depth, could be stablished.

Compactación inducida por el tráfico de máquinas en suelo forestal

Se realizaron ensayos en campo para evaluar los efectos del trafico de cosecha y extraccion sobre las propiedades fisicas del suelo en una plantacion de alamos (Populus sp.). Fueron evaluadas: a) zonas sin transito vehicular y b) zonas transitadas por maquinaria de cosecha y extraccion. Para ambas situaciones se efectuaron mediciones de resistencia a la penetracion, humedad y densidad aparente. La resistencia a la penetracion en las zonas transitadas resulto significativamente mayor hasta los 150 mm de profundidad, siendo el efecto del transito detectable hasta los 380 mm. A partir de los 150 mm ambos tratamientos superaron valores de 1,5 MPa, que reducirian el crecimiento radicular. La densidad en los sectores con transito resulto significativamente mayores, siendo en los primeros 80 mm significativamente menor respecto a los estratos mas profundos para ambos tratamientos. La presencia de capas de elevada densidad aparente influye en la compactacion superficial.