1 / 31

Scheduling irrigations for apple trees using climate data

Scheduling irrigations for apple trees using climate data. Ted Sammis Go to Home. The Water Budget Method. The tree root zone is a reservoir Water is added by irrigation or rainfall. Water is removed by evapotranspiration.

marci
Télécharger la présentation

Scheduling irrigations for apple trees using climate data

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Scheduling irrigations for apple trees using climate data Ted Sammis Go to Home

  2. The Water Budget Method • The tree root zone is a reservoir • Water is added by irrigation or rainfall. • Water is removed by evapotranspiration. • Added water can be lost by deep percolation if the amount exceeds the field capacity of the soil.

  3. Management Allowed Depletion • Management Allowed Depletion Is the percent of water that can be removed before soil moisture stress limits growth. • (For Apples MAD is %50.)

  4. Evapotranspiration • Evapotranspiration is determined from climate data to calculate potential Evapotranspiration (water used by grass) and a scaling coefficient or crop coefficient for apples. • The crop coefficient depends on the size and spacing of the trees and the ground cover. • The crop coefficient changes throughout the growing season increasing to a maximum at maximum leaf cover

  5. Crop coefficient scaling function for trees based on projected area

  6. Calculation of Evapotranspiration • Potential Et= 0.3 inches / day • Et= K*PET • K= 0.8 • Et= 0.8* 0.3 = .24 inch/day

  7. Calculated when to irrigate • Readily available water (RAW) = available water (AW) * management allowed depletion (MAD) • Example: • Aw = 2 inches/ft * 3ft root zone • Mad = 50% • RAW= 2 inches/ft*3ft*0.5 = 3 inches

  8. Irrigation Interval • Irrigation interval = RAW / Et / day • Irrigation interval = 3 inches / 0.24 inches /day = 13 days • Irrigation interval changes with changes in the Et or soil type. • Et changes with tree cover and weather.

  9. Source of Potential Evapotranspiration • New Mexico Climate Center Homepage • http://weather.nmsu.edu

  10. Temperature sensor and radiation shield

  11. The Water Balance Spread Sheet • Inputs • Climate data, paste into spread sheet • Soil water holding capacity inch/ft • Irrigation amount applied at each irrigation. • Output – Date to irrigate on

  12. The Water Balance Spread Sheet

  13. Conclusion • The water balance-check book method can be used to schedule irrigations for Apples. • The water use of Apples can be calculated from climate data, and this is all that is needed to apply the correct amount of water at the correct time • The check book method can also determine the decrease in yield and amount of water stress when time between irrigation is to long.

More Related