Usable forms of nitrogen can be intentionally be increased in the soil by what?
Usable forms of nitrogen can be intentionally increased in the soil through various means, such as:
1. Nitrogen Fertilizers: Adding nitrogen-based fertilizers like ammonium nitrate, ammonium sulfate, urea, or organic fertilizers such as compost or manure can provide additional nitrogen to the soil.
2. Legume crops: Growing leguminous plants (such as beans, peas, lentils, alfalfa) that have a symbiotic relationship with nitrogen-fixing bacteria can increase the available nitrogen in the soil. These bacteria convert atmospheric nitrogen into a usable form through a process called nitrogen fixation.
3. Crop rotation: Implementing a crop rotation system where nitrogen-depleting crops (such as corn or wheat) are followed by nitrogen-fixing crops (legumes) helps replenish the soil with usable nitrogen.
4. Cover crops: Planting cover crops like clover, vetch, or winter rye during fallow periods can help seize nitrogen from the atmosphere and store it in the soil. These cover crops can then be tilled or incorporated into the soil to release the captured nitrogen.
5. Animal manure: Applying manure from livestock or poultry to the soil can introduce nitrogen in an organic form. The decomposition of the manure releases usable nitrogen for plant uptake.
6. Microbial inoculants: Using inoculants that contain nitrogen-fixing bacteria or mycorrhizal fungi can enhance the capacity of plants to access and utilize nitrogen in the soil.
It's important to note that the specific method used to increase nitrogen levels in the soil should be determined based on soil testing, crop requirements, and environmental considerations.