Much of the United States has experienced drought this year and in times like these it is good to remind people some simple things that can be done to increase soil moisture before disaster strikes.
1. Add fresh organic matter to the surface of soil. This helps with water infiltration. When bare soil is hit by rain it can form a crust that sheds water-- increasing surface runoff. You can add organic matter by simply pulling weeds and dropping them in place to act as a mulch. This is not a good idea if those weeds have gone to seed already. Other mulches also work to protect bare soil.
2. Incorporate finished compost into soil in the spring, and in-between crop successions. This will help improve soil structure and thus water-holding capacity. As compost is further broken down by soil-dwelling organisms it is formed into aggregates with particles like sand, silt and clay. The arrangement of the soil aggregates allow for plant roots to access water that is being held by the aggregates.
3. Avoid tilling. Tilling can destroy aggregates and soil pores- both keys to healthy soil capable of holding water.
4. Use a cover crop. If you are letting an area go fallow or putting your garden/farm to bed for the winter, always plant a cover crop appropriate to the season and climate you are in. The roots of cover crops create additional pores that improve soil structure, the crop can be cut and turned under before cultivation to be used as a compost/mulch, and soil remains covered during rains.