One of the best gardening techniquesis the use of a green manure. A green manure is a cover crop, a plant that is grown in your garden and then turned under and mixed into the soil. A good cover crop improves soil, prevents erosion, helps control weeds, adds nutrients to the dirt, and encourages beneficial insects.
It does take a little know-how and pre-planning however.
Green manures are fast growing plants that are sowed in a flower bed or garden. Legumes are often used as green manures because of their nitrogen fixing properties. These plants, which include alfalfa, vetches, and clover actually take nitrogen out of the air and transport it to the soil. As nitrogen is one of the most important soil nutrients, this is a great benefit. Other plants, such as buckwheat and red clover can be used to smother weeds, as they are very fast growing. Closely planted sunflowers also inhibit weed growth, as they prevent nitrogen fixing bacteria from flourishing. Alfalfa and clovers also attract a variety of predatory insects, which will help rid a garden of insect pests. The insulating quality of green manures, keeping the soil warm in the winter and cool in the summer, encourage earthworms as well, with their wonderful soil conditioning activities.
Perhaps the biggest benefit derived from the use of green manures however, is the organic material introduced to the soil when the plants are turned under. Most cover crops are fast decomposing, and are stirred back into the ground before seed production. This infusion of plant material to the soil keeps the soil loose and fertile.