WATERING THE GARDEN

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If, on hot summer days, the crops use more water than is replaced, dry air spaces are created within the soil, and the bridge to the water table is broken. Conversely, if a real downpour hits and the air spaces become flooded to the point of excluding oxygen altogether, plants can literally drown—because roots must have air as well as water.

Whether or not your garden soil will retain water well without becoming oversaturated is determined, for the most part, by its structure. But don't feel that you must live with the type of soil that's currently in your plot. The great equalizer, compost, can help improve any ground that has trouble properly absorbing or retaining water.

Take sandy soils, for instance. They often have large spaces between their particles that allow for excellent drainage— if there is existing moisture in the soil. If, however, as might be the case in an extremely sandy soil, those spaces are completely filled with air, they can actually become a barrier to water penetration. Rain will be able to penetrate no deeper than the first few inches, so even though the garden has gotten a good soaking, deeper levels will remain bone-dry. When that happens, plant roots tend to seek out only the upper few inches of soil and will thus be quite susceptible to heat and moisture loss.

Compost added to such a sandy soil will act as a moisture-retaining wick. It should be incorporated deeply—say, six to eight inches—so it will also help attract roots downward.

Silty soil acts in much the same way. Its powdery, flourlike texture can let water slip right through . . . just as the soil itself would sift through your open fingers. In the process, that water will quickly leach nutrients from your plants. Here again, compost will give your plot a better water-retaining capacity.

Clay soils have another problem: They have so few air spaces that they're too easily flooded by water. A sticky, slimy, wet clay soil can easily drown roots. The addition of as much organic matter as possible to clay soils is a definite must in order to lighten the soil to allow plant roots more room to breathe. At the Eco-Village, we turn in at least an inch of compost (and preferably more) before planting any crop in our clay-heavy beds.

Turning under green manure (or cover) crops is often another good way to add more humus to the soil. Our own clay plot, however, doesn't have sufficient belowground air to stimulate the needed decomposition of turned-under crops, so we actually skim off most of the green matter and compost it before working it in.

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