Drip-irrigation systems employ small gaps at standard distances in a hose, leading to the slow trickle of water droplets which percolate the soil over a protracted period. These systems use 30 – 50% less water than conventional methods.[69] Soaker hoses help to reduce water use by up to 90%.[70] They connect to a garden hose and lay along the row of plants under a layer of mulch. A layer of organic material added to the soil helps to increase its absorption and water retention; previously planted areas can be covered with compost.