What Is Green Manure?
If you’re looking at the landscape around you, chances are good that there are some plants growing in areas where they don’t belong. Perhaps it’s an area of grass or weeds that should be mowed regularly but isn’t because no one has time to do so. Or maybe it’s a patch of ground with nothing more than rocks and dirt. Green manures are crops grown specifically for this purpose. They include legumes such as clover or alfalfa; grasses like rye, oats, wheat, barley, sorghum, millet, buckwheat, and corn; and other grains including rice, soybeans, sunflowers, and peanuts. The most common types of green manures used by organic farmers are winter cover crops because they grow quickly during cold weather months and then die back naturally before spring planting time.
Green Manure Crop Benefits
The most obvious benefit to using green manures is that they are an excellent source of nitrogen which can be used by plants during their growth cycle. Nitrogen is one of the three macronutrients needed by plant roots to grow healthy leaves, stems, flowers or fruit. It also helps maintain soil structure and improves water retention capacity. In addition, it aids in weed control because it inhibits germination and seedling emergence.
Making Green Manure
There are several types of green manures available to gardeners. Some examples include clover, buckwheat, vetch, alfalfa, mustard, turnip greens, radish, and others. These plants have been used by farmers since ancient times because they provide valuable resources while improving the health of their land. When choosing which type of crop you want to grow, consider what your goals are with this project.
How Do I Choose the Green Manure to Plant?
The time to turn under the green manure depends on how long you plan to let it stay in place. For example, if you intend to leave it until next year, then you would wait until late summer or early autumn.
However, if you plan to remove it this year, then you may choose to turn it under now. It is important to note that some green manures take longer to break down than others.
Growing Green Manure Crops
The first step to growing your own organic matter is to get started with some of these easy-to-grow plants that will help you build up your soil’s organic content over time. These plants add nitrogen to the soil through their roots, which helps build up organic matter content. They also help prevent erosion by holding moisture in place during dry spells.
1) Legumes
Legume seeds contain nitrogen fixing bacteria which helps them x atmospheric nitrogen into a usable form called ammonia. This process takes place when leguminous plants such as clover, vetches, alfalfa, peas, beans etc., take up N from the air through their roots and convert it into ammonium ions.
2. Non-legumes
Non-leguminous non-nitrogen fixing green manures include buckwheat, vetch, rye grasses, sorghum, oats, barley, wheat straw, corn stalks, sunflower stems, potato vines, sugar beet tops, turnips, radishes, mustard greens, kale, cabbage leaves, lettuce, spinach, kohlrabi, carrots, onions, garlic, celery, cucumbers, peppers, tomatoes, eggplant, melons, pumpkins, squash, etc.
Uses of Green Manure Leaching
It occurs when water seeps through the topsoil layer and carries away valuable nutrients such as phosphorous, potassium and calcium. This happens because there’s no vegetation present to hold back rainwater. As a result, the soil becomes depleted of essential nutrients. In addition, this leads to poor plant health due to lack of nutrition.
Erosion
It is a another problem caused by bare soil exposed to wind and rainfall.
Improving Soil Fertility- Plants absorb water and nutrients through their leaves and stems, which makes them useful for improving soil health. In addition, when the plants die, they release carbon dioxide back into the air, making the soil richer in oxygen. This increases the number of microorganisms present in the soil, thus increasing the rate of mineralization.
Cover Crops
Cover crops increase fertility by adding organic matter and nutrients to the soil. Legumes, including alfalfa, red clover, white clover, crimson clover, pea, bean, lentil, lupine, vetch, chickpeas and fava beans, make excellent green manures.