The ability to produce enough food for a country is an essential task of any society. If a nation must import food they will always be at the mercy of other nations for their very existance. The basis of any good agricultural system is the ability to produce large amounts of crops. The crops go not only to feed people but in large portion to feeding, and fattening cattle.
Plants need light, water, carbon dioxide, and nitrogen to grow. Nitrogen is undoubtly the most important plant nutrient. That is why the production of inorganic nitrogen fertilizers has been such a benefit to farmers in developed nations. Unfortunately, these fertilizers are expensive, tend to leach from soils, and eventually contaminate our drinking water. Developing nations can not afford to fertilize their fields in the amounts needed year after year to get the yields needed. Developed nations can not afford the continuing pollution of surface waters.
How can this problem be solved? Just ask a soil microbiologist and they can give you several alternative solutions to the application of inorganic fertilizers. One such solution is the application of bacteria called Azospirillum. This group of bacteria can take nitrogen from the air and provide it to the plant (nitrogen fixation).
Nitrogen fixation is not the major benefit Azospirillum can give to plants. When Azospirillum are placed on the roots of plants they have the ablity to increase the numbers of root hairs (from Iowa State University) on each root. These root hairs are important in helping the plant get water from the soil. This benefit the plant derives from its association with Azospirillum helps the plants do better in drier places.
Another benefit the plant gets from associating with Azospirillum is that the bacteria produce plant growth factors (auxins) that cause the plant to produce more roots. The better the root system, the stronger the plant. Stronger plants produce more food. The plants given Azospirillum are also as productive as heavily fertilized plants that do not have the Azospirillum added.
Researchers have found that they can apply less fertilizer per acre and get good yields. This would help farmers in developing countries increase their yields without significantly increasing their costs. Using less fertilizer would also lower the amount of fertilizer polluting the drinking waters in developed countries.
The following link is a summary of what we have discussed above by Dr. Zimmer. Here is a summary of a three year study of Azospirillum by Sean Murphy at Iowa State University.
Unfortunately, the yields have been somewhat inconsistent. Some portions of a farmer's land may respond very well to the addition of Azospirillum.
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