When weather conditions are dry, it is a good time to explore ways to conserve water. Organic material is essential to good soil. Well-decomposed organic matter helps increase water and nutrient holding capacity of the soil. Undecomposed material like leaves and clippings used as surface mulch can help conserve moisture and keep weeds under control. Nematodes, those little microscopic worms that feed on your roots, will do less damage in a high organic soil. Organic matter may also increase the minor element and microbiological activity of your soil.