Nitrogen fixing plants

As mentioned previously, the fixation-denitrification cycle (Fig. 12-7) is the most heavily perturbed by humans. This is due to both the increasing use of nitrogenous fertilizers and the planting of nitrogen-fixing plants. One of the... 

Model studies in nitrogen fixation and cobalamin chemistry Nitrogen-fixing plants... 

Allelopathic Interference of Black Walnut Trees with Nitrogen-Fixing Plants in Mixed Plantings... 

Why are the seeds of nitrogen-fixing plants, such as soybeans and peanuts, unusually high in protein ... 

Was this youT answer Plants use nitrogen to build proteins. Nitrogen-fixing plants assimilate a lot of nitrogen and so produce proteins in large quantities. 

To protect against pests, organic farmers alternate the crops planted on a particular plot of land. Such crop rotation works fairly well because different crops are damaged by different pests. A pest that thrives on one seasons crop of corn, for example, will do poorly on the next season s crop of alfalfa. For fertilizer, organic farmers rely on compost, shown in Figure 15.29. They also include nitrogen-fixing plants in their crop-rotation schedules. 

Fixation due to planting of nitrogen-fixing plants 3. Total biological fixation (1+2 above) 150 43 ... 

Nitrogen-fixing plants are also capable of reducing NOg" in the roots and/or leaves of the plant. In soybeans, there is evidence to suggest that reduction may occur in both roots and leaves (26). There has been diflSculty, however, in detecting nitrite reductase activity in soybean root or nodule tissue (61). Using NOs", we have demonstrated that both tissues actively assimilate and incorporate into organic com-... 

The quantity of food required to feed the ever-increasing human population far exceeds that provided by nitrogen-fixing plants. (Section 14.7) Therefore, human agriculture requires substantial amounts of ammonia-based fertilizers for croplands. Of all the chemical reactions that humans have learned to control for their own purposes, the synthesis of ammonia from hydrogen and atmospheric nitrogen is one of the most important... 

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