Where irrigation wastes water
Irrigation brings water from a source to the plants. Every system has a way to take the water from the source, a way to move it to the field and a way to apply it to the crops. Water is wasted in several ways. Some evaporates into the air, especially in hot sun. Some runs off the soil before it soaks in. Some leaks from cracked pipes or channels. And sometimes people simply water more than the plants need. Old flood irrigation lets water run over the whole field, so a lot may be lost. A sprinkler sprays water into the air, which is better but some evaporates. Drip irrigation lets small drops fall by the roots, so little is wasted. A moisture sensor can tell people when the soil is dry. Watering in the cooler morning or evening also reduces evaporation.
| System | How it works | Where water is lost |
|---|---|---|
| flood | water runs over the field | evaporation, runoff |
| sprinkler | sprays water into the air | some evaporation and wind |
| drip | drops fall by the roots | very little |
| Waste | Fix |
|---|---|
| leaks | repair pipes |
| runoff | slow the water or use drip |
| evaporation | water in cool hours |
| too much water | use a moisture sensor |
Sketch and label. With a grown-up, draw three simple sketches of a flood, a sprinkler and a drip system. Label the water source, pipes and plants. Mark with a red pencil where water might be lost. Which system would you choose for a small garden?