Measurement and estimation of different environmental variables

Measurement of air temperature

Thermometer placed in Stevenson screen

Thermocouples connected with data logger

Measurement of air temperature

Measurement of rainfall

Rain gauge

Measurement of wind speed and wind direction

Rotating cup anemometer

Kestrel 2500 hand-held weather meter

Sonic anemometer (for horizontal and vertical wind speed)

Measurement of wind speed

Measurement of relative humidity

Hygrometer

Measurement of light intensity (lux)

Lux meter

Light meter

Potential evapotranspirationA measure of the ability of the atmosphere to

remove water from the surface through the processes of evaporation and transpiration assuming no control on water supply.

Potential evapotranspiration

Potential evapotranspiration

 Penman–Monteith equation (after Howard Penman and John Monteith) Predicts net evapotranspiration (ET), requiring as input daily mean temperature, wind speed, relative humidity and solar radiation

Drought index

A number representing net effect of evaporation, transpiration, and precipitation in producing cumulative moisture depletion in deep duff or upper soil layers.

Measurement of solar radiation

Pyranometer

Pyranometer

Measurement of solar radiation

Measurement of solar radiation

Campbell-Stoke Sunshine recorder

PAR measurement over crop canopy (µmol photons m-2s-1)

Accupar

Questions?