- Aquaflex - Vendor information about a sensor that measures both soil moisture and soil temperature over a large volume of soil.
- IAS Laboratories - Agronomy laboratory providing plant, soil and water analyses. Includes information on programs for crop production that enable the grower to more efficiently identify nutrient deficiency.
- Kel Instruments Co. Inc. - Specializing in soil pH and salinity test instruments.
- Percolation and Soil Test Guides - Provides guidance on how to perform tests.
- Soilmoisture Equipment Corp. - Manufacturer of instruments to measure and extract soil moisture. Products include tensiometers; extractors, compressors and manifolds; plant water status console; salinity sensing equipment; soil permeability equipment; samplers; and related instrumentation and electronic systems.
