The application of geostatistics to plant nematology was made by evaluating soil and nematode data acquired from 200 soil samples collected from the A(p) horizon of a reed canary-grass field in northern Minnesota. Geostatistical concepts relevant to nematology include semi-variogram modelling, kriging, and change of support calculations. Soil and nematode data generally followed a spherical sem...

Distribution of the citrus nematode (Tylenchulus semipenetrans) was studied over 18 months in a 6-year-old orchard of grapefruit (Citrus paradisi cv. Ruby Red) on sour orange (C. aurantium) rootstock. The 1.8-ha orchard was under chemical weed control, no tillage, and flood irrigation. Highest numbers of nematodes were found in the top 15 cm of the soil profile. The nematode population peaked i...

Soils used for vegetable production in Florida are sandy, have low organic matter content and fertility, and can support the growth of soil-borne pathogens. Some growers choose to apply compost as an antagonistic suppression approach to combat soil-borne disease effects on crop yields or to increase organic matter and improve soil fertility. The objective of this on-farm study was to determine ...

the split-block experimental design with three replications was used to study the effect of subsoiling in different distances from drain axison soil salinity,and wheat yield. the measurements included soil cone index, soil bulkdensity, infiltration rate and electrical conductivity of saturated extract. each treatment was composed of two factors. the main factors consisted of 3 different distanc...

Simulations de grandes déformations et post-rupture des murs de soutènement segmentaires utilisant la méthode des mailles-libres (SPH) ABSTRACT: Numerical methods are extremely useful in gaining insights into the behaviour of reinforced soil retaining walls. However, traditional numerical approaches such as limit equilibrium or finite element methods are unable to simulate large deformation and...

This paper is part of a study to develop robots for farming. As such power requirement to operate equipment attach to such robots become an important factor. Soil-tool interaction plays major role in power consumption, thus predicting accurately the forces which act on the blade during the farming is very important for optimal designing of farm equipment. In this paper, a finite element investi...

Introduced as a system in earthquake engineering in 2004 [6], rocking walls are a fairly new system in earthquake engineering. Their performance has been proven, both in research as in practice. However, a few uncertainties about their behavior still remain. One of these uncertainties is the effect of radiation damping on the motion of the system. Existing estimations for the radiation damping ...

performance optimization of chisel tine was proposed by using a chisel plow with adjustable rake angle. effective treatments consisted of soil moisture at 0.5, 0.7 and 0.9 of plastic limit (pl), three rake angle of 30, 40 and 50 degree and speeds of to 3, 5 and 7 km h-1. the measured parameters included draft, soil disturbance area, soil upheaving area, clod mean weight diameter (mwd), specific...

Seepage failure in the form of piping can strongly influence the stability of block-in-matrix-soils (bimsoils), as well as weaken and affect the performance of bimsoil structures. The multiple-factor evaluation and optimization play a crucial role in controlling the seepage failure in bimsoil. The aim of this study is to improve the ability to control the piping seepage failure in bimsoil. In t...