Many farmers have heard of the concept of plants for the spillover effect. This refers to the idea that by planting more trees, or bettering existing cover crops (such as alfalfa or sheep's milk) in a field, or changing the type of crop to plant, more land can be planted for the future use. The idea is not just to provide an additional food supply but also to prevent erosion and prevent water runoff. If the crop is planted in a field with sufficient cover for the animals and the soil conditions allow for a good rain to run off without running off into nearby water resources, the plant itself will survive and flourish.
In practice, however, plants for spillover effect are often planted in fields where cattle or sheep are grazing. Unfortunately, they are unable to survive in these areas without supplemental help. However, they do provide food and shelter for other wildlife living in the area. So without this added help, the local wildlife population may suffer in large numbers. Also, farmers who have planted crops that rely on these animals may find that their yield is reduced due to reduced animal browsing.
There are many reasons why the soil in an area becomes depleted of nutrients. These reasons include tilling to increase agricultural production, farming of forage for food, and the removal of topsoil to plant new crops. Also, when trees are removed, the trees are usually stripped of their leaves and tree fruit. This leaves the soil poorer in nutrients and makes it more vulnerable to erosion and pollution.
A natural solution to this problem is for farmers to plant cover crops instead of planting additional food supply crops. One example is alfalfa. It can provide healthy nitrogen and phosphorous for livestock and can tolerate occasional herbicide applications. Some other cover crops are also beneficial. These include cover rice, which is resistant to weeds; vetch, an excellent crop to feed livestock; and red clover, which provides a source of both protein and humectants for human consumption. Cover crops, if planted in abundance, will restore the depleted soil, improve water quality and attract beneficial wildlife to the area.
Another way to restore soils is to reintroduce biological matter into the soil. Many beneficial organisms are already present in soils. In fact, these natural substances may be responsible for the food supply of millions of animals worldwide. One excellent example of a biodegradable substance is bacteria. Bacteria can help to restore the depleted soil by converting carbon dioxide in the soil into carbonate. This process will release nitrogen into the soil in return, greatly enhancing its productivity.
Invasive species pose a greater challenge when trying to restore soils. They can invade an area so completely that they eliminate the natural balance of the environment. These unwelcome visitors can include rodents, snakes, and insects.
Invasive plants can be quite difficult to control once they have established themselves. The best solution is prevention. Do your best to avoid introducing new plants or animals to an area. Plant native plants, which are commonly referred to as natives, such as black-eyed Susans and blueberries, instead of imported ornamental plants. A great place to search for non-intrusive plants is a nursery. If you plan to relocate plants, consult with a local nursery to see which plants are most suitable for your new location.
Plants for spillover effect are a wonderful way to deal with soil erosion and the resulting barren areas. However, do not introduce any plants until you have carefully considered their impact on native biodiversity. Native plants are generally easier to maintain than exotic ones, but no plant is worth losing a species of habitat over.