Regional Soil Moisture Comment for Nelson

 

Nelson Evapotranspiration Last 7 Days

This data is based on average canopies for each crop and is based on the Riwaka Weather Station
DateDaily ET (mm/Day)Estimated Apple Crop Use (Std)Estimated Apple Crop Use (Dwarf)Estimated Grape Crop Use (Std)Estimated Kiwifruit Crop Use (Std)Estimated Hop Crop Use (Std)
16 May0.40.40.30.10.40.0
17 May0.70.70.50.20.70.0
18 May0.70.70.50.20.70.0
19 May0.8




20 May





21 May0.7




22 May1.1











7 day total4.41.81.40.61.80.0

ET Files

Evapotranspiration reported above is for well watered grass (ETo), it is the water loss from grass and soil.  Evapotranspiration can be estimated for a specific crop using ‘crop factors’ to adjust reported ETo to ETc or Evapotranspiration of the crop.

Crop factors are linked to the active leaf area of the crop.  As the canopy grows (young to old trees or within a growing season) the crop factor, and therefore the Evapotranspiration of the crop, increases.

 ETc   =   ETo * Crop Factor   =   Crop Water Use

e.g. apples mid season where ETo is 35mm/week, ETc is 35 * 0.9  =  31.5mm/week

Typical crop factor values for apples, kiwifruit and grapes are:

Apples - Std Apples - Dwarf Kiwifruit Grapes
Budbreak   0  0   0  0 
Early season   0.4  0.3   0.5  0.20 
Mid season   0.9  0.7  1.0  0.35
Late season   1.0  0.8  1.1  0.45