Rapidly growing mycobacteria (RGM) inhabit soil and water but certain strains represent a health risk for human and animals. Both clinical and soil RGM may be under selection pressure for resistance to tetracycline (TET) antibiotics, since tetracyclines are administrated to humans and farm animals, and TET residues enter soil through manuring; however, resistance to TET and the presence of TET-...

field study was conducted at five villages of Botswana namely, Tsabong, Tshane, Mathathane, Motlhabaneng and Tsetsejwe during the periods of June to August 1999 and June to August 2000. The objective of the study was to assess and compare the soil physicochemical properties of soils at the five villages and to study the effect of cultivation on some soil physical properties. Parameters measured...

water erosion causes severe soil damage in northern forests of iran which is associated with different rut depths in skid trails. the aim of this study was to assess rutting and soil displacement on skid trails to mitigate water erosion. therefore the research was carried out in eight parcels of district no 3 of shafarood forest in the north of iran. in order to evaluate the amount of erosion i...

in many structures, the applied lateral loads are comparable with gravity loads. these types of piles which are subject to high lateral load are usually divided into two categories including long and short piles. the general methods to estimate lateral bearing capacity of short and long piles are based on ultimate bearing capacity and allowable horizontal displacement respectively. in the prese...

Press-wheels are wheels designed to compact the soil above seeds in “seed cover” region. Soil compaction, produced by press-wheels of seeders, affects seedling emergence and early plant growth. The Discrete Element Method (DEM) was used model amount compaction from a press-wheel with varying down forces. predict sinkage rolling resistance press-wheel. results were validated data bin tests sandy...

A previously introduced two phase model was used to assess its capability in predicting the behavior of reinforced soil walls under working stress conditions. The two phase model is a homogenization method based on the virtual work theorem. The reinforced soil medium is considered as the superposition of two continuous phases, the reinforcement and matrix phases that interact within the medium....

Subsurface drip irrigation is defined as application of water below the soil surface through emitters, with discharge rates generally in the same range as surface drip irrigation. It has many advantages over surface drip. To see the response of subsurface drip irrigation on okra yield, a study was conducted at Indian Agricultural Research Institute, New Delhi, India during 2003 and 2004. Okra (...

Abstract Alfalfa ( Medicago sativa ) is one of several legumes that affected by Aphanomyces root rot (ARR) caused euteiches . Symptoms ARR on alfalfa seedlings include a yellow‐grey discolouration roots, rotting and loss lateral stunted growth, chlorotic foliage reduction nitrogen‐producing nodules roots. Infection can also occur adult plants leading to roots nodules. At the seedling stage, dec...

Plant growth is directly affected by soil water, soil aeration, and soil resistance to root penetration. The least limiting water range (LLWR) is de®ned as the range in soil water content within which limitations to plant growth associated with water potential, aeration and soil resistance to root penetration are minimal. The LLWR has not been evaluated in tropical soils. Thus, the objective of...

in the realistic manner, piles are similar to the slender columns that soil around them acts as a lateral support. the piles situated in the liquefiable soil layers, loss their lateral supports due to the liquefaction resulted from the seismic ground motion. in this case, pile has the potency of axial instability similar to the unsupported columns. this instability can lead to the lateral buckl...