Soil Inoculation: Giving Plants a Nitrogen Fix

Tuesday, December 5, 2017

Soil inoculation has been around for a long time, but it takes on new meaning today given the host of products capable of introducing new bacteria to the soil. Many years ago it was learned that certain bacteria have beneficial effects on soils. Scattering soils that had the beneficial bacteria was found to produce better results in the innoculated fields. Field soils where leguminous crops such as peas, beans and lentils had been grown were found to be especially beneficial. Small amounts of the soil in which a legume had been grown, transferred to very poor soil newly seeded to the same legume, made the crop do well.

Leguminous crops are very rich in protein. Soybean, for example, is richer in protein than any cut of beef. For this reason, legumes have a very high feeding value, which makes them especially desirable as part of the ration for young animals. However, to produce this much protein, the plant must have a large amount of nitrogen. But plants cannot make use of the nitrogen in the air. It is the ability of leguminous plants to take nitrogen from the air and convert it to a usable form that makes them so valuable.

If you dig up a legume you’ll see many wart-like growths on its roots; these are called nodules. If the nodules are opened and part of the inside is examined under a microscope, you’ll see numerous small bodies with a rod-like form. These are nitrogen-fixing bacteria and are not found on other common crop plants. This is why legumes are key to beneficial inoculation of other soils, as their nitrogen-fixing bacteria become part of the vaccination process. The bacteria living within the nodules are able to take the nitrogen from the soil air and give it to the plant in a usable form. While this process isn’t necessary for either the bacteria’s or the plant’s  survival, the growth of each is greatly benefited by the presence of the other.

No land should lay barren. Without cover, there is no carbon/sugar exchange taking place between the plant and the microbes in the soil. If the soil microbes can’t be fed by the plant’s exudation process then they go into stasis or worse, die. Leguminous cover crops are an inexpensive way to put nitrogen in the soil and promote the crop’s exchange with the microbial community below. This helps contribute to the building of organic matter that contains 95% of the nitrogen and over 50% of the phosphorus in the soil.

Andaman Ag is leading the charge when it comes to understanding soil biology and how we can assist growers to make better decisions resulting in less disease and insect pressures and more quality crops. We offer a number of products like compost teas, fish hydolysates and seawater concentrates that are excellent for soil inoculations and include nitrogen-fixing bacteria. It’s an exciting time to be in agriculture!