Water Savings

How does conventional irrigation waste water?

All forms of conventional irrigation ultimately pour water into the soil. The soil is a very leaky container. It loses water both above and below: Above by evaporation; Below by flow into the water table. Only a very small fraction of irrigation water is actually absorbed by the plants, which are the intended recipients. The rest is wasted.

The diagram above makes it easy to see how little water it actually intercepts from the amount provided by conventional irrigation. The tiny roots of the plant must compete for water against the much larger ground surface and water table.

This diagram shows how much less water is required using Direct Irrigation. The water goes directly to the plant, then a small portion is overflowed each week to remove accumulated solutes.

How much water does Direct Irrigation save?

To put this into perspective, look at these tables:

We use 10% as a nominal estimate here; it may be more or less in practice depending upon circumstances.

Table 1: Water Input Held Constant at 100 Liters

Conventional Irrigation	100 liters in	90 liters wasted to evaporation and water table	10 liters used by plants	efficiency 10%
Direct Irrigation	100 liters in	90 liters to plants	10 liters wasted to evaporation and water table	efficiency 90%

Table 2: Water Absorbed by Plants Held Constant at 100 Liters

Conventional Irrigation	100 liters to plants	900 liters wasted	1000 liters required
Direct Irrigation	100 liters to plants	11 liters wasted	111 liters required	89% savings compared to Conventional Irrigation

The growing plant gets more water from Direct Irrigation than it would from irrigation via soil because the plant gets the water first, before it can be lost !

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