How to Easily Determine if Irrigation is Even and Water Volume is Sufficient

How to Easily Determine if Irrigation is Even and Water Volume is Sufficient

The most intuitive way to assess the effectiveness of irrigation is to check if the water is distributed evenly and in sufficient quantity. Without professional instruments, you can quickly evaluate and adjust your irrigation methods through simple field observations and hands-on tests. The core methods for assessment are: observing the surface, checking the soil, measuring the depth, and observing the crops.

Simple Methods to Determine if Irrigation is "Even":

Observe surface water flow and puddling: Walk around the field during and immediately after irrigation.

If you see water flowing only in a few lines, with large areas remaining dry, it indicates uneven water distribution (possibly due to uneven furrows, clogged sprinklers, or incorrect sprinkler angles).

If you see some areas with standing water while slightly higher areas nearby remain dry, it indicates uneven ground, causing the water to "run off."

(For sprinkler irrigation) Observe whether all sprinklers are rotating normally, whether the spray patterns overlap well, and whether there are any obvious dry spots.

Post-rain trampling test: Half a day or a day after irrigation (after the surface water has seeped in), walk around the field in different locations wearing flat-soled shoes.

Feel if the soil softness and color are consistent. If some areas feel soft and sink easily with a dark color, while others are hard and light in color, it indicates significantly uneven watering.

"Cutting open" the soil layer to view the profile: This is the most reliable method. About a day after irrigation, use a shovel to dig a vertical soil profile approximately 20-30 centimeters deep at several evenly distributed points in the field (e.g., at the beginning, middle, and end of the field, or at the center and edges of the sprinkler irrigation area).

Observe whether the moisture level and color of the entire profile are consistent. If the depth of wetting and the depth of color vary significantly at different points, it proves that the watering is uneven.

Simple Methods to Determine if Water Volume is "Sufficient":

Measure the wetting depth: Using the soil profile described above, directly measure the depth of water penetration with a shovel or ruler. Does this depth reach the main activity layer of the crop roots? For most vegetables and shallow-rooted crops, a watering depth of 15-25 centimeters is generally required; for field crops like corn or fruit trees, a deeper watering (30-50 centimeters or more) may be necessary. If only the top few centimeters are wet, the watering is definitely insufficient.

Using a simple probe or stick: Insert a thin steel rod, thick wire, or pointed wooden stick into the soil after irrigation.

Feel the resistance: Dry soil offers significant resistance and is difficult to penetrate; moist soil allows for easy insertion. The depth to which the probe can be easily inserted quickly indicates the depth of the moist layer.

Observe the crop's reaction: After a period of time (half a day to a day) after watering, observe the crop's leaves.

If previously wilted leaves perk up and become turgid, it indicates that the watering was timely and sufficient.

However, if the crop remains listless for a long time after watering, or the leaves are dark in color and growth is slow, it may indicate insufficient watering (or excessive watering leading to root rot).

Calculate time and gain experience: For fixed irrigation methods (such as drip irrigation, fixed sprinklers), record the reasonable irrigation time required to achieve sufficient moisture depth. This allows you to determine the water volume by controlling the time.

In summary: The most effective combination method is to dig up the soil at different points in the field about a day after irrigation, comparing the moisture depth and soil profile moisture consistency. Simultaneously, observe the surface and the condition of the crops. By developing this simple checking habit, you can quickly identify irrigation problems, whether it's adjusting the duration, improving the method, or repairing equipment, ensuring that every drop of water is used effectively and that crops grow uniformly and vigorously.