This prepatory plant [Also it can be a food crop as well] is usefull for the particular application of fixing nitrogen from the air, into the soil using a symbiotic relationship between roots and bacteria. It is also a form of nitrogen which is easy and reggealy available for plants to uptake. For this reason it is an excellent choice to sow before planting heavy feeders like Kannah-Besem, tomatoes, corn, cabbages, cucumbers etc. But it can also be used with good results before planting any vegetable, not just heavy feeders. The roots go deep on these plants (while working with certain bacteria to ‘fix’ nitrogen [የናይትሮጅን]), which helps to break up ground and brings nutrients up higher, for use by other plants – see pictures. Like mustard, these plants can be sown and grown in very cold conditions. They are soft and become food for soil life very quickly, if they are cut before they grow around 40cm’s. When planted in September – December they are often perfectly reggy in Spring (Northern Hemisphere). They can also be planted in, throughout spring, to early summer.
When it is time to sow / plant the vegetables, the beans are cut down close to the ground like mustard, and a good soil is left which is easy to make drills, and sow seeds into. The results of fruit bearing crops, cabbages and other vegetables and erbs will be better thanks to field / broad beans before. The high nitrogen (የናይትሮጅን) can make crops leafy, if not fed with a feed to harmonize this. Feeds made of plants like, valerian, comfrey, woodland fern etc will counter-act any plants that begin to go too leafy.
Most nitrogen fixing plants create good soil conditions. Do not be sparing on the sowing and growing of nitrogen fixing plants, grow plenty for a full stock of nitrogen.
The row closest is reggy to be chopped down,
Time to chop them down, and plant an actual crop;
Rake them to the side and use as cover in between all-reggy established crops, they make excellent cover. The roots have locked plenty of nitrogen in the soil, and the roots themselves will rot down, enhancing the soil structure. However, for example, a section of these roots will be dug up to show the root nodules, depth and allowing to show the roots ability to hold the soil while penetrating down.
A drill is made for the crop’s seeds, the fork is used to ligtly break up the top, no need to go beyond 3 inches;
A root with nitrogen-bacteria (የናይትሮጅን) nodules;
These were small plants: on bigger plants the roots and nodules will be deeper – while more and more good bacteria start colonizing with the roots along the way. Notice each plant has a deep tap root – this really helps penetrate soil breaking it up, creating channels etc, while holding the soil togather from erosion etc.
The plants grown in the soil that is prepared by field beans, will be happy. After the field beans in winter, a pre-crop of spinach and mustard was sown before these main crops, see here for pictures and more information – SPINACH.
There are a series of 3 videos on youtube, which go in depth into the relationship between the bacteria and the roots/plants. The plants are constantly giving out ‘a signal’ to which certain, specific bacteria will respond to. The relationship is begun and eventually, nodules will be formed on the roots, to house the bacteria, and nitrogen (የናይትሮጅን) fixation will be taking place.
Sharon Long (Stanford) Part 1: Cooperation between bacteria and plants for protein nutrition