TECHNOLOGY ADVANCEMENTS
• other factors: management practices, pest pressure, irrigation system performance, soil characteristics, etc. can affect ETc.
• Captured precipitation: This includes how much rainfall fell and how much can be effectively captured by the soil. This relates to precipitation minus the water that is lost to runoff or deep percolation into the soil. A good rule of thumb is often 50% of precipitation is captured by the plant in normal precipitation cases.
Using satellite, weather and soil informa- tion, growers have access to technology that provides these metrics on a weekly basis to make such a calculation possible. This type of technology provides action- able, field-specific insight on crop health, crop progression and crop water demand (evapotranspiration) anywhere on Earth.
Key features & benefits
Common data include a field identifier, acreage, ETc (previous week), forecasted ETc (next week), field ETc uniformity (0-100) from the latest satellite date as shown in figure 1, year-to-date ETc for the current year, total year-to-date ETc for the previous year, and weekly average uniformity change as a percentage. With this dataset, growers have a complete picture of the field’s water consumption and can compare it to the prior year.
Benefits include quantified and directly observed growth metrics, accurate ETc (crop water demand) measures for irrigation management practices, crop health assessment via uniformity and uniformity change over time, and historical year-to-date ETc for current year and past year for contextual relevance.
Here are some examples to illustrate these nuances. Figures 2 and 3 show how similar fields can have different uniformities. Figure 2 shows two fields operated by the same grower but with very different uniformities across the field. By getting timely information that is directly observed, the grower can address these nonuniformities early and prevent yield loss.
12 Irrigation TODAY | Summer 2021
Figure 1. Example of an ETc uniformity map
Figure 2. These ETc consumption images show how the same grower can have fields with very different uniformities across the field.
Figure 3. These two fields were right next to each other and looked exactly the same to the trained human eye, but they have different nonuniformities in their ETc demand that can be seen spectrally by the satellites.
irrigationtoday.org
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48
