Understanding Nitrogen in our Crops

Every four thirty in the afternoon when I was seven years old, my mother always reminds me to water the plants in our backyard. I often wonder if water is enough just to make a plant healthy enough to grow? However, my mom as an agriculturist answered my question. She taught me that plants are like human, water isn’t enough to make it fit. Plants also need nutrients in order for them to grow well.

Thus, the crops that we eat need to have to intake their specific nutrients such as Calcium, Phosphorous, Potassium, Sodium and Nitrogen to name some. These fertilizers help us to have a good and healthy harvest. Of all the nutrients mentioned, we will further know what’s nitrogen has to do in our crops.

Merriam-Webster Dictionary defines nitrogen as a colorless tasteless odorless element that as a diatomic gas is relatively inert and constitutes 78 percent of the atmosphere and that is a constituent of organic compounds found in all living tissues.

Mrs. Rodelyn Caro, Extension Officer of the Department of Agriculture Region VI explained that Nitrogen is basically an element needed in the crop production. Ms. Lavinia Corpus, Philippine Rice Research Institute Development Staff added that nitrogen is a principal plant nutrient that has a responsibility to attain the economic yields from one’s production. The management of nitrogen utilization should be in large amounts and it should be balanced with the other nutrients.

So how does nitrogen actually works in our crops?  According to Nachurs Alpine Solution they explained how can we further understand nitrogen’s role in our crops. Most of the Nitrogen (97 – 98%) in the soil is tied up in the organic matter and unavailable to plants.  Only 2 – 3% is in the inorganic form of nitrate (NO3–) and the ammonium (NH4+) forms that is available to plants.  The organic matter (at proper moisture, temperature, and oxygen content) is continuously being broken down by microorganisms and released as inorganic Nitrogen into the soil.  This process is called mineralization.  An opposite process also occurs where microorganisms feed on inorganic Nitrogen.  This process is called immobilization.

Moreover, in healthy soil both processes are taking place at the same time.  When large amounts of stover (straw or corn stalks) which have a high carbon and low Nitrogen content is incorporated into the soil, immobilization can take place at such a rapid rate and deplete the soil of all or most of its available Nitrogen.  Later the microorganisms bodies will breakdown and decay going through the process of mineralization.  This Nitrogen is again released into the soil and becomes available for plant growth.

Thus, during the process of mineralization, most of the organic matter is first converted to ammonium (NH4+).  The process that breaks down the ammonium (NH4+) to  nitrate (NO3–) by nitrifying bacteria is called nitrification.  This process is very important because nitrate is readily available for use by crops and microorganisms. Nitrates are very mobile in the soil.

However, nitrogen can’t be in our crops forever. There are instances where nitrogen is lost from the soil. These are plant uptake, microorganisms, nitrates that move out with drainage water, and the loss of nitrates by denitrification.

What is this denitrification? The Pocket Webster School and Office Dictionary defines denitrification as the loss or removal of nitrogen of nitrogen compounds; specifically: reduction of nitrates or nitrates commonly by bacteria (as in soil) that usually results in the escape of nitrogen into the air. This is usually seen in wet areas in fields where the crops are described as yellow and underdeveloped.

Artificial nitrogen is not even exempted in losing them.  Nachurs Alpine Solution stated that the urea applied to the surface converts rapidly to NH3 and escapes into the air as ammonia gas when adequate moisture, temperature, and the enzyme urease is present.

What is urea? Merriam-Webster defines urea as a soluble weakly basic nitrogenous compound that is the chief solid component of mammalian urine and an end product of protein decomposition that is synthesized from carbon dioxide and ammonia, and is used especially in synthesis (as of resins and plastics) and in fertilizers and animal rations.

Is there a way to avoid this? Nachurs Alpine Solution gave details that to avoid this loss, incorporate the urea, or irrigate immediately.  A urease inhibitor can also be utilized to reduce loss.

To further understand Nitrogen’s importance in our crops, there are different functions that it can offer to us. First of all, Nitrogen inside the plant alters to amino acids. Merriam-Webster defines amino acids as amphoteric organic acids containing the amino group NH2. In other words, these are building blocks for proteins.  These amino acids are then used in forming protoplasm, which is used in cell division.  These building blocks are also important in producing essential enzymes and parts of the plant and can become a part of the stored proteins in the grain.

The dark green color of the leaves that you can see in the crops is basically nitrogen’s reason. Thus, lets you know that a high concentration of chlorophyll was done. Nitrogen plus the high concentrations of chlorophyll make use of the sunlight as a source of energy source in order to perform necessary functions of the plant such as nutrient uptake.

Are there ways to determine that a crop is poor in nitrogen? Of course there is.

When Nitrogen is poor, it usually gives us a yellowing or chlorosis of the leaves. It will start in the oldest ones and will eventually go to the younger ones if not treated.

Also, the stability of the crops can take effect if nitrogen deficiency happens. What happens is that the crop will draw out nitrogen from the leaves and the stalk for the grain fill. If this happens, the stem will have stability problems.

Lastly, the obvious part is when a crop is shorter or grows slower than the ones rich with nitrogen.  You see, nitrogen stress lessens the amount of proteins in the plant.

That’s why it is very important to check on your crops from time to time to ensure that everything is in good condition. In every nutrient that is lacking, it is very important to take immediate as soon as possible.

In Iloilo City, Rice Crops are known to be the primary source of food of the Illonggos. According to Hector D. Peñaranda, Ph. D. of the Department of Agriculture Region 6 rice crops have the following nutrients Phosphorous, Nitrogen, Potassium, Sodium, Calcium and Magnesium wherein each one of them has its own function to have a high profitability crop production.

In this instance, nitrogen’s functions are building up of plant tissue, needed in protein synthesis and nitrogen is a component of chlorophyll. We can also identify whether the crop has nitrogen deficiency.

The following are nitrogen deficiency symptoms in accordance to Dr. Peñaranda’s hand outs in his Fertilizer Management in Crops Seminar in Da-R6:

  1. Levels are yellowish green in the 0 Nitrogen omission plot, since fertilizer is not applied.
  2. Levels of Nitrogen deficient plants are light green, narrow and smaller.
  3. Tillering is reduced where Nitrogen is deficient.
  4. Tillering isgreater where Nitrogen fertilizer has been applied.

In WESVIARC- Visayas Experiment Station in Hamuagaya, Jaro can be found lots of crops that is being experimented and utilized by different kinds of nutrients. Crops in Iloilo City that are being utilized by nitrogen are Rice Crops, Legume, and Mongo to name some.

According to the Department of Agriculture Region 6 Agribiz Profile, mongo is a Nitrogen-rich crop used in intecropping rotation and relay cropping. Farmers plant mongo during the second cropping season due to its low moisture content. Why? It is because it is fairly drought-tolerant crop with a short maturity period and at the same time it is also used as a substitute for soybean meal in poultry feed formulation.

Also, for further information, mongo is planted by row-grill method, or broadcast method. Row-grill method or broadcast method is by using a walk-behind drop spreader or hand-held spreader with a crank to scatter granular or bulk fertilizer on the ground. This is good for flowerbeds, lawns, trees and vegetable gardens. Fertilizer may be broadcast on of the ground before planting and then tilled or watered into the soil. If it is broadcast on growing plants and watered into the soil, it is called topdressing. After which, the harvesting starts within 65-72 days after planting when pods turn brown or black and leaves turn yellow. It is done by handpicking the pods which are then sundried, threshed and packed in sacks.

In our society, crops are the primary source of food. More and more are giving birth to tis world and we need food in order to live. If not with the help of nitrogen rapid healthy growth of crops will be not that easy.  According to Larry Laroca of The News Today most plants need more nitrogen than other elements especially during the rapid growth stages.

When nitrogen is managed properly it can lead to a higher effectiveness and productivity for the crops. However, don’t forget to give your crops a balanced amount of nutrients in order for you to have a healthy harvest.

REFERENCES:

Department of Agriculture, Region 6, Parola Wharf, Iloilo City

Hector D. Peñaranda, Ph. D., Department of Agriculture Region 6. Fertilizer Management in Crops Seminar

Nachurs Alpine Solution . Nitrogen: An Essential Element in Crop Production. Retrieved August 29, 2013 from http://www.nachurs.com/nitrogen.html

Mongo. Retrieved August 30, 2013 from http://www.rfu6.da.gov.ph/agribiz/mongo.htm

Definition of Broadcast Method. Retrieved August 30, 2013 from http://homeguides.sfgate.com/four-methods-applying-fertilizers-25517.html

Laroca, Larry (2011).Nitrogen fixing trees as source of fertilizers Retrieved August 30, 2013 from http://www.iloilonewstoday.com/home/4946-nitrogen-fixing-trees-as-fertilizer-sources.html

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One thought on “Understanding Nitrogen in our Crops

  1. Pingback: Nitrogen is lacking in fields, but grows in cities | Productos Pilar

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