Glossary
Probe Sensors
6" SENSORS
Sensors located six inches below ground, evaluating the soil for deep to shallow-rooting plants.
12" SENSORS
Sensors located 12 inches below ground, evaluating the soil for moderate to deeper-rooting plants.
18" SENSORS
Sensors located 18 inches below ground, evaluating the soil for deep-rooting plants like trees and large shrubs.
A - G
AERATION
The available oxygen content in the soil, which relates to the ability of microbes and roots to respire. Low aeration typically indicates poor soil structure, compaction, or flooding.
AIR TEMPERATURE
The degree of heat in the air. Each crop has optimal maximum and minimum temperature conditions for development.
H - N
HUMIDITY
The amount of water vapor in the atmosphere. When humidity and temperatures rise, plants may close stomata to reduce water loss, which prevents photosynthesis.
ILLUMINANCE
The amount of light spreading over a surface, measured in lux (lx). Most plants require at least 1,100 lx for 12 hours daily to benefit from fertilization.
NITRATE (NO3)
An inorganic form of nitrogen used by plants for chlorophyll, amino acids, and nucleic acids.
NITRATE LEACHING
The loss of nitrate as rainfall or irrigation moves it downward past the root zone.
P - R
pH
The measure of acidity or alkalinity of a soil, ranging from 0 to 14. A pH of 7 is neutral; most plants thrive between 5.5 and 7.0.
PHOSPHORUS
A chemical element required for energy transfer, root development, and protein synthesis.
POROSITY
The amount of space between soil particles. Ideal soil contains 50% pore space for adequate water and air flow.
POTASSIUM
Naturally occurring element that improves root growth, drought tolerance, and activates growth enzymes.
RESPIRATION
The release of CO2 due to soil organisms respiring. Concentration above 10% can negatively impact plants and microbes.
ROOT PENETRATION
The process of roots growing through soil, highly impacted by soil structure, moisture, and compaction.
S - W
SALINITY
Total salt content in soil reported as electrical conductivity (EC). High salinity forces plants to use more energy for osmotic regulation, decreasing yield.
SOIL EROSION
The transportation of soil particles by wind, water, or gravity, resulting in the loss of fertile topsoil.
SOIL MOISTURE
The Available Water Content (AWC) held in pores between field capacity and permanent wilting point.
SOIL TEMPERATURE
The warmth in the soil which impacts seed germination, nutrient uptake, and microbial processes.
WATERLOGGING
When soil is saturated for extended periods, leading to a lack of oxygen that prevents root respiration.
Units & Measurements
°C / °F
Metric (Celsius) and US (Fahrenheit) units of temperature.
dS/m
DeciSiemen per meter, a unit used for measuring soil salinity.
FOOTCANDLE (FC)
A non-SI unit of illuminance; one footcandle is equal to 10.76391 luces.
KG/HA & LBS/ACRE
Units for fertilizer application rates. 1 kg/ha = 0.89 lbs/acre.
LUX (LX)
The SI unit of illuminance equal to one lumen per square meter.
PPM
Parts per million; 1 ppm is equal to 1 milligram per kilogram.