Biological fertilizers, or bio fertilizers, replace chemical fertilizers in improving crop yields and soil fertility. Traditionally farmers and gardeners relied on chemical fertilizers to restore nutrients to the soil. However, chemical fertilizers pollute surface and ground waters, destroy helpful microorganisms in the soil and increase susceptibility to plant diseases. Bio fertilizers, in contrast, use natural biological wastes to boost soil fertility without the harmful effects. According to the United States Department of Agriculture, the use of bio fertilizers is an important component of organic food production.
Compost is made from items traditionally discarded as garbage, including certain food scraps and peels, paper, lawn clippings and dead leaves. Helpful bacteria feed on carbon-rich scraps and use nitrogen-rich scraps to reproduce, breaking down the garbage into nutrient-rich soil that will fertilize and replenish spent fertility in garden soil. Hobby gardeners can easily make compost at home. Moist scraps, like lawn clippings and vegetable peels, provide nitrogen, while dry scraps, like fallen autumn leaves and shredded paper, provide carbon. Although most professionals recommend using two-parts carbon for every one-part nitrogen, composting expert and author Barbara Pleasant reminds gardeners getting started with compost that it is a natural process that doesn't require overthinking. While precisely maintained compost piles can produce compost in just a few weeks, just about any compost heap will produce finished compost eventually. Start piling together your carbon- and nitrogen-rich garbage and throw in a handful of dirt to provide some helpful bacteria to get the process underway.
On family farms, before the invention of organic fertilizer, manure provided a cheap and easy bio fertilizer for gardens and crops. Manure can be purchased at garden centers or acquired from local farms. Manure from farms, however, must be composted before it is safe to use, as fresh manure is high in nitrogen and ammonia, both of which can burn plants or prevent seeds from germinating. Fresh manure may also contain weed seeds that will wreak havoc on unplanted garden beds. Manure from most farm animals is safe to use, but gardeners should observe several precautions. First, contact your local extension office to have your soil tested and to find out what kinds of manure are the best to use for your soil's needs. Animals that have fed on pesticide-treated plants or have been given antibiotics may pass these substances through their manure, stunting the growth of plants in your garden or killing off helpful soil bacteria. Always check with the farmer about what foods the animals have eaten and what medications they have been recently given before using manure. Finally, manure may contain harmful bacteria, so always wear gloves when handling it.
Also called green manures, cover crops are planted during nonproducing seasons or years. They serve multiple purposes, the chief of which is restoring lost nutrients such as nitrogen. Legumes, such as beans and red clover, have helpful bacteria in their roots that help restore lost nitrogen in the soil by making nitrogen available in the air available to crops. Typically cover crops are planted after harvesting, last throughout the winter and are tilled under in the spring. Cover crops called living mulches coexist with plants, keeping soil fertility high and preventing erosion. In addition to restoring essential nutrients, cover crops also prevent erosion, improve drainage and prevent pest infestations.