Using evapotranspiration as a reference for making irrigation decisions

Using evapotranspiration as a reference for making irrigation decisions has advantages and disadvantages that farmers should consider:

Advantages of using evapotranspiration:

1. General information: Evapotranspiration is a general measure of water loss in soil and plants due to evaporation and transpiration. Provides an overview of your crop's water needs over a wide area.

2. Historical data: You can obtain historical evapotranspiration data to better plan your irrigation over time.

3. Low initial cost: Calculating evapotranspiration does not require expensive equipment such as sensors.

Disadvantages of using evapotranspiration:

1. Lack of precision: Evapotranspiration does not always reflect the specific conditions of your field, since it is a general average for a region. It may not take into account local factors such as soil moisture, crop type and the exact weather conditions on your plot.

2. Requires manual adjustments: You will need to adjust evapotranspiration-based irrigation recommendations based on your actual field conditions. This can be complicated and require experience.

3. It doesn't consider actual plant demand: Evapotranspiration focuses on water loss, but it doesn't consider how much water your plants need at any given time. This can lead to inefficient water use if crop conditions are not closely monitored.

4. Can lead to overwatering or underwatering: If you rely solely on evapotranspiration, you could overwater or underwater based on changing conditions in your field.

In summary, evapotranspiration can be useful as a general guide for planning your irrigations, especially if you don't have access to expensive sensors. However, it is important to remember that it is not always accurate and requires manual adjustments to suit the specific conditions of your crop and terrain. Combining evapotranspiration information with local data and observation of your plants can help you make better watering decisions.