Soil scientists are the best bet to avoid playing the game of vege-roulette. Though a landscaper may know the terrain and have a general sense of the climate and sun exposure, only soil scientists and agronomists can identify the specific chemical and biological history of a particular site. Although the soil may appear healthy with good color and adequate drainage, the soil scientist can find out if the landscape is suitable for plants, or if the soil contains residues from herbicides. Many homeowners are surprised to find that they have laid down their roots in an area that was once a salt marsh or a dumping ground for construction materials. Further complicating matters, topsoil is frequently buried deep in the profile during grading, underneath layers of compacted subsoil.

Bob Baier, CLIA of The Earth Laboratory believes that soil scientists are an under-utilized resource. According to Baier, what soil testing gives the landscaper is "visibility". One might compare traditional methods of planting to throwing darts at a board while blind-folded. The soil test removes the blindfold and presents a well-defined target. "And for specifying amendments it's great insurance," says Baier.

The tests that Baier uses to analyze the soil condition range from the standard cookbook variety to high tech computerized methods. One of the easiest ways to evaluate soil suitability is to check for weed growth. If you haven't got weeds, then you might have a soil suitability problem, residual herbicides or perhaps something more ominous. A simple indicator of soil quality is the growth test. The soil is potted, while radish or trailing salt plant seeds are planted into the soil. The speed and quality of germination is a good indicator of the basic soil suitability.

One of the persistent challenges in California landscapes is reducing the residual salt content. The indigenous soil is salty to begin with, but factor in the Colorado River, which delivers about one ton of salt per acre-foot of water, and you've got problems. In addition, the low-lying coastal regions where property sells at a premium, are subject to high tides that impinge on the water table, making soil briny and sterile. Baier uses "quick check" pH and electrical conductivity (EC) tests to measure the salinity and pH of the soil. Depending upon the results of these tests a combination of amendments, drainage systems, and even water filters may be used to avoid increasing salt.

The innovative IRIS Advantage ICAP (Inductively Coupled Argon Plasma) Spectrometer series combines the speed and accuracy of a simultaneous ICP with the flexibility of a sequential system.

In the past four years, soil testing has taken a leap forward in the efficiency and accuracy with which the components of soil samples can be identified. Wallace Labs is one of the companies that has taken a lead in soil characterization by using an inductively coupled plasma spectrometer (ICP) from TJA Solutions called the IRIS Advantage. The instrument identifies the specific light frequencies emitted by solution extracts of the soil sample. The elements of the sample are excited in the ICP to the point where they emit light in the ultra violet and visible portion of the spectrum. The light that is emitted from the sample under these conditions is represented as a fingerprint or signature that is specific to a catalog of chemical profiles. The key to the instrument's sensitivity is a patented 262,000-pixel Charge Injection Device (CID), which allows the capture of the entire emission spectrum from 165 to 1,000 nm. Every analytical wavelength is available, so that the optimal wavelengths can be selected for each element in every sample. When combined with ThermoSPEC software, analysis of samples is made routine.

The new technology has permitted Dr. Garn Wallace to increase his productivity by 50 to 100 times and has enhanced the precision and accuracy of his tests by identifying such difficult to characterize elements such as arsenic and vanadium. The technology has allowed Wallace and associates like Bob Baier with a broader spectrum of results with greater speed and at lower prices.

Axial plasma: unique long torch for maximum sensitivity and freedom from interference.