Soil tests can help with crop production or new construction.
Soil tests are a valuable tool used to help farmers get the most out of their crops. In the construction industry, preliminary testing is mandatory in most places to detect contamination, determine suitability for construction, and select the proper foundation type. The various types of soil tests include contaminant and mineral concentration tests, compaction tests, cone tests, consolidation tests, and percolation tests.
Legumes help enrich the soil by adding nitrogen.
Since the nutrients needed by plants are different for each species, soil testing for agricultural purposes involves assessing the levels of nutrients needed by specific crops. Soil composition also varies at different depths, so samples should be taken from the level where most root activity will occur. Two frequently tested element levels are nitrogen and phosphorous. There are a variety of methods to measure nitrate and ammonium, the most common forms of nitrogen used by plants. The Bray P1 test is used to check phosphorus levels in acid soils, while the Olsen Baking Soda test checks phosphorus levels in alkaline soils.
Testing is usually done to determine the toxicity of soil on construction sites.
Many countries have instituted restrictions on building on sites that contain potentially toxic or carcinogenic waste, so knowing the history of a property prior to development is essential. Where a site has been used for a purpose that could result in contamination, soil testing should be done prior to any development. A unique on-site testing method for such substances is a laser-induced fluorescence system. This test employs a truck-mounted sensor that can detect petroleum hydrocarbons and uranium below the surface. Other methods include soil vapor testing and the use of pore water samples taken from the designated area.
Field soil testing helps farmers get the most out of crops.
Before installing underground septic systems or sewage filtration systems, required soil tests typically include percolation and soil profile tests. The percolation test simulates the conditions of a septic system and measures the ability of the soil to absorb liquids. In addition to drilling test holes to the level where the system will be placed, it is also necessary to ensure that the water table at the lowest point is more than two feet (0.61 m) below the level of the septic system. Soil profile tests assess the texture of the soil, whether or not it is saturated with water, and the depth of the underlying rock layer.
The construction of the tunnel requires a very specific analysis of the soil in the area.
Soil tests are essential in construction to determine the types and depths of foundations needed for different buildings in different locations. Geotechnical soil testing involves drilling into the soil of a proposed site and then performing laboratory tests on the samples to determine the composition of the soil. Compaction tests are essential to determine if clay soils are compatible with construction, what type of equipment should be used to compact the soil, and how much compaction is required before laying foundations.
The soil mechanics in an area may need to be studied before a foundation can be concreted.
One of the most common in situ tests for investigating soft soils is the cone penetration test, developed in the Netherlands in the 1950s. This relatively inexpensive soil testing method measures resistance and friction against a shaped instrument. of cone when pushed towards the ground. at a constant speed. The main objective of this test is to predict the vertical capacity of deep foundations and for soil stratigraphy.
Another reason to test the soil is to detect the presence of expensive clay. Expansive clay contains water-absorbing minerals that cause it to swell when wet and contract when dry, resulting in volume changes of up to ten percent. These clays appear all over the world and are the main cause of damaged foundations. Building on expanding clay is possible as long as the base is constructed in a way that maintains moisture control. Drilled pillar foundations in expanding clay have been used in some areas, although the most stable approach seems to be to extend the foundations below the zone of buoyancy of the water.