Overused and unhealthy soils lack organic matter and microorganisms. Adding nutrients to your soil via compost and other organic matter helps your soil become healthy which in turn produces healthier vegetation. With healthier soil, you will conserve water because you increase the ability of water to reach your plant's roots while also reducing erosion and run-off. Improving your soil's health will also create an environment beneficial for organisms like earthworms, which are a very good indicator of a healthy soil. Earthworms migrate and live in healthy soils and help keep that soil area healthy.
Organic mulches enhance the soil's ability to store water.
They cover and cool the soil, minimizing evaporation. Organic mulches include aged manure, compost, bark chips and wood chips. Organic mulches also help with weed control and reduce soil erosion. If the mulch is too deep, water can have a difficult time reaching the plant roots. Inorganic mulches include rock and gravel.