With all the chitchat about drip irrigation and water conservation on social media, you would think that it’s the only way to reduce watering in the garden. But it’s not true. The soil holds the key to lower water bills, and the techniques are simple and low-cost.
Increasing soil organic matter and mulching are the main ways to reduce water use in the garden. Increasing soil organic matter is a long-term strategy; it doesn’t happen overnight. But mulching can happen overnight, and as the mulch breaks down over the season it adds to the organic matter in the soil as well!
Reduce watering by increasing the soil’s organic matter
Increasing the soil’s organic matter reduces water use in the garden! It’s the key component in reducing water use, no matter where you live. Organic matter acts like sponge and stores water. The higher organic matter also increases the soil’s infiltration rate. Gabe Brown’s farm in Bismarck, North Dakota illustrates this point beautifully.
They don’t need to irrigate even though they live in an area that gets only get 15 inches of rain per year. In 1991 their initial soil organic matter was less than 2 percent; it now runs about 5 to 6 percent organic matter. Because of the higher organic matter, the average water infiltration rate has increased from ½ inch per hour (in 1991) to 8 inches per hour. No runoff!
Reduce watering by adding organic mulch
Mulch greatly reduces soil moisture loss, so you don’t have to water as often during the hot summer. Don’t take my word for it. Michael McMillen’s 2013 research on the effect of mulches on soil evaporation rate irrefutably proves that mulches reduce soil water loss.
- A 2-inch mulch of either straw, leaf debris or leaf clippings reduce water loss by 40 percent compared to bare soil.
- A 4-inch mulch reduced water loss by 50 percent.
- Increasing the mulch depth to 6 inches didn’t decrease soil evaporation further. Values were the same as the 4-inch mulch.
Imagine! For the low price of a couple bags of mulch, you’ve reduced your water use by half.