To determine the relationship between changes in soil physical properties due to tillage and growth of loblolly pine (Pinus taeda L.) seedlings, we measured soil moisture and penetration resistance for a range of tillage treatments on two Upper Coastal Plain sites in Georgia and correlated these measurements to the growth of individual seedlings. The five tillage treatments were: no-till (NT), ...

one of the most valid and efficient models of long rod projectile penetration in homogeneous targets is tate and alekseevskii’s (a&t;) model. based on tate’s model, the present research tries to calculate the optimum speeds to achieve the maximum penetration depth in the homogeneous targets. the proposed collision speed-penetration depth diagrams are developed using tate’s model. in this way, v...

Increased soil strength due to soil compaction or soil drying is a major limitation to root growth and crop productivity. Roots need to exert higher penetration force, resulting in increased penetration stress when elongating in soils of greater strength. This study aimed to quantify how the genotypic diversity of root tip geometry and root diameter influences root elongation under different le...

Increased soil strength due to soil compaction or soil drying is a major limitation to root growth and crop productivity. Roots need to exert higher penetration force, resulting in increased penetration stress when elongating in soils of greater strength. This study aimed to quantify how the genotypic diversity of root tip geometry and root diameter influences root elongation under different le...

A computer simulation of cone penetration in layered soil was carried out using axisymmetric finite element (FE) to investigate soil deformation and soil hardpan prediction during cone penetration. The FE analysis was performed in ABAQUS, commercially available FE package. Soil was considered as a non­ linear elastic plastic material modeled using Drucker Prager material model with hardening op...

We quantify mechanical processes common to soil penetration by earthworms and growing plant roots, including the energetic requirements for soil plastic displacement. The basic mechanical model considers cavity expansion into a plastic wet soil involving wedging by root tips or earthworms via cone-like penetration followed by cavity expansion due to pressurized earthworm hydroskeleton or root r...

Soil compaction is a common problem that affects several soil properties and plant growth. In order to assess the effects of soil strength expressed by its mechanical resistance on roots, a growth chamber experiment was conducted at the Universidade Federal do Rio Grande do Sul, Porto Alegre, in 1994, during 35 days (530 GDD, 0oC base temperature) on a typical Paleudult soil. Treatments, using ...

for a determination of soil characteristics one should have access to instruments that can measure these characteristics, including: soil penetration resistance with high accuracy. one of the accurate instruments commonly employed in soil penetration determinations is cone penetrometer. this apparatus, by measuring soil cone index at different soil depths can provide useful about information ab...

investigation of projectiles penetration phenomenon has been carried out in non-cohesive soil (sand) targets under dry, saturated and compacted conditions. analytical studies have been performed on the linear and non-linear soil models to obtain penetration depth formulae for ogival nose projectile and the results are verified by experimental studies. in present work, three ogival nose projecti...

many farmers periodically use deep tillage operations to alleviate compaction in the soil profile caused by natural factors or machinery traffic. in 2012 and 2013, a study was initiated in the pannonian region of croatia to study the effects of no-tillage (nt), conventional tillage (ct) and deep tillage (dt) on soil compaction, measured by (bd), soil water content (swc), penetration resistance ...