Ammonia Vs. Nitrate in Soils

Healthy soil is the foundation for beautiful and productive gardens.

Diligent gardeners and growers are concerned with providing plants with proper nutrition. Even though plants are like tiny solar-powered factories that process their own food through photosynthesis, oftentimes in poor soil, the grower needs to help them thrive by providing additives to the soil in plots that are deficient in essential nutrients. If the soil is found lacking in nitrogen, adding ammonia or nitrate can be one way to replenish the balance of nutrients.

Identification

Nitrogen is an essential element required for life and although it makes up approximately 80 percent of the Earth's atmosphere, most plants do not use it directly in this elemental form. Instead the nitrogen must be converted into a nitrate or ammonia and ammonium to be taken up through the plant's root system. Plants attract bacteria to live around their root systems by providing them with sugars. The bacteria in turn synthesize the nitrogen in the surrounding soil into a form the plant can use.

Considerations

Aerating the soil around plants can aid in the production of naturally occurring nitrates. Naturally occurring ammonia results from composted materials and may supplement available nutrients in the soil through plant decomposition. To be certain what needs to be added to a particular plot of ground, the grower can determine what the soil lacks by testing. A soil test will reveal the acidity level (pH) and the available minerals in the sample. If it is found that the soil remains deficient in essential nutrients, the grower may want to provide an additive.

Types

For soils found deficient in nitrogen, nitrates and ammonia can be added directly to the soil by application of animal manure or through the addition of commercially produced fertilizers. When adding commercial fertilizers, the packaging materials will list ingredients. In the U.S., standard fertilizer labels list the concentration per volume of nitrogen first, phosphate second and potash third. For example, a commonly used garden fertilizer, 5-10-5, contains 5 percent nitrogen, 10 percent phosphate and 10 percent potash.

Benefits

A proper balance of nutrients in the soil can lead to a more abundant harvest.

Adding the required nitrate or ammonia to the soil will benefit plant life in the treated plot by assisting in the photosynthesis process, and improving the overall quality of leaf crops. A healthy plant produces higher yields of fruit, and thus increased seed production. Plants grown in soil with well-balanced nutrients are more resistant to the fungi, bacteria, fungi, nematodes and viruses that cause plant diseases. A healthy plant is also more resistant to insects which spread the diseases.

Misconceptions

Adding ammonia directly to the soil is for all intents and purposes, adding nitrate, as bacteria in the soil will synthesize the majority of the ammonia into a nitrate which the plant can then absorb through its root system. According to the University of Missouri (Agriculture) Extension Service, "The amount of crop growth is essentially the same whether nitrogen fertilizer is applied as ammonia (NH3), ammonium or nitrate (NO3-)." Therefore, the final decision in choosing between ammonia and nitrate is arbitrary.

Warning

Excessive amounts of nitrate in the soil are toxic, whether applied through commercial fertilizer products or through the addition of manure to the soil. In addition, too much nitrogen in some vegetable crops, such as beets, carrots, lettuce, parsnips, squash, sweet potatoes, turnips and watermelon, may reduce the yield and quality of harvested produce. Ammonia too can be hazardous in large enough quantities. It's important to read and properly follow instructions on fertilizer labels to achieve the greatest benefits while maintaining minimum harm.

References

• University of Missouri Extension": G9804 Nitrate in Soils and Plants
• "University of Kentucky College of Agriculture": AGR-147: Managing Soil Nitrates For Agronomic Efficiency and Environmental Protection
• "North Carolina Department of Agriculture & Consumer Services": Plant Nutrients
• "IPCS Inchem": Ammonia (EHC 54, 1986)
• "PhysicalGeography": 9(s) The Nitrogen Cycle