Chemical Fertilization and its impact on Agriculture
The Agricultural sector is regularly facing considerable problems such as low Soil Organic Carbon, low fertilizer use efficiencies and the imbalance between the nutrient removal and addition to the soil. This scenario has made the people rethink about it and improve the agricultural packages and processes in meeting the dreams of millions of people.
The maintenance of soil fertility and sustaining the crop production is of worldwide importance and also the management of soil health is very important for securing sustainable agriculture production and the sustenance of biodiversity.
Modern agriculture majorly relies on various inputs such as pesticides, chemical fertilizers, proper irrigation, improved seeds and herbicides. The employment of these inputs in Agriculture increases the crop production, but their improper use can reduce the quality and the productivity of soil which is a matter of concern.
Chemical fertilizers are those compounds which encompasses nutrient concentration in the soil that is needed for the growth of plant or we can say that it is a man made material that supply all the required nutrients to the plants and this fertilizers and pesticides are some unavoidable risks in agriculture but still they continue to be a vital mean for food safety and their negative impact can also be not left avoided.
Chemical fertilizer has a vital role in increasing the fertility of soil and productivity of crops and different countries use different types and different amounts of fertilizer. The Fertilizer industry is a source of heavy metals and radionuclides which consists of metals such as Cadmium, Arsenic, Mercury, Nickel, Lead, Copper and Natural radionuclides such as U²³⁸, Th²³², and Po²¹⁰.
The fertilization is responsible for the accommodation of heavy metals in the soil system and through the soil the plants absorb these fertilisers and create their entry into the food chain.
Large amounts of chemical fertilizers are also used in greenhouses, aquacultures during the top season and their prolonged use can even decline the soil organic matter content and it can even increase environment pollution and soil acidity.
These chemical fertilisers are detrimental to agriculture as their major content are salts which are very harmful for plants and soil. These fertilizers lessen the vital minerals and nutrients and do not provide benefit in restoring the fertility of the soil and its nutrients.
Here, in this article we will study more about Chemical Fertilisers and their impact on Agriculture.
Chemical fertilizers are the substances that are supplied to the crops to increase their productivity and it is used by the farmers on a regular basis to increase the crop yield.
These fertilizers contain essential nutrients that are required by the plants including some important elements such as Nitrogen, Potassium and Phosphorus. They also enhance the water retention capacity of the soil and increase its fertility.
Types of Chemical Fertilizers
In general, there are three kinds of chemical fertilizers available. They are:
- Nitrogenous Fertilisers
- Phosphorus Fertilisers
- Potassium Fertilisers
This type of fertilizer contains Nitrogen in the form of ammonical Nitrogen such as Ammonium chloride, Ammonium Sulphate; Amide Nitrogen such as urea; Nitrate Nitrogen such as Calcium ammonium nitrate where both ammoniacal and nitrate nitrogen fertiliser is present. This type of fertilizer is used for meeting the nitrogen deficiency in the soil and it is one of the most beneficial fertilisers for the plant as it supplies nutrients to both plant and the land.
In this fertilizer Phosphorus is present in the form of phosphate and it is a vital terrestrial fertilizer but its requirement is less as compared to nitrogen fertilizers.
The Phosphorus found in the Protoplasm of the cell plays an important role in the growth of cell and proliferation and it is beneficial for the growth of roots of the plants.
The Potassium fertilizers are found in the form of muriate (Potassium Chloride) and the sulphate of Potash. Potassium Sulphate is necessary for the healthy growth of plants and for the formation of carbohydrates in the plants.
It is divided into two subtypes : Potash in Chloride and in non-chloride forms. Sulphate of Potash and muriate of potash are the examples of Potash in non chloride nature and Potash in chloride form respectively.
Advantages of Chemical Fertilizers
Chemical fertilizers are utilised for restoring the fertility of the lands. The land loses its fertility because of the enormous number of crops cultivated during the year.
These fertilizers are very fundamental in the development of the crop, the quality parameters, yield and also for the well being of the soil when it is utilised appropriately.
The fertilizers make nutrient status better and the nature of the soil by adding the necessary supplements. Some of the other advantages of chemical fertilizers are:
- It enhances the power of resistance in plants.
- It grows better crops.
- The growth of plants gets faster.
- The plants obtain all the necessary nutrients from the chemical fertilizers in equal proportions.
- The soil absorbs chemical fertilizer readily as it is water soluble.
- There is no unnecessary ingredient found in chemical fertilizers.
- The growth of plants and development becomes accurate.
Drawbacks of Chemical Fertilizers
The health of soil and plants deteriorate by improper employment of chemical fertilizers and some of the primary drawbacks are as follows:
- Some fertilizers disturb the properties of the soil.
- Artificial fertilizers become costly for small farmer
- It enhances the emission of nitrate.
- Crop growth is not sufficient so it results in the decrease in crop production.
- Some crops are damaged due to insufficient water supply, particularly in the regions with less rainfall.
- When Nitrogen fertilizer is applied in the field, only the bacteria already present there turns it into nitrate.
- It spoils the constitution of the soil due to the lack of organic material.
- Some of the soil dwelling organisms such as earthworms make the soil fertile but they are destroyed due to the application of fertilizers.
- Nitrogen fertilizers are toxic to both animals and plants.
Impact of Chemical Fertilizers on Agriculture
Chemical Fertilizers have several impacts on the Agriculture sector, basically on the Soil and Plants.
We will see them one by one.
- Soil Quality
The increased application of chemical fertilizers has worsened the quality of soil, especially urea, muriate of potash, and single super phosphate. The soil serves as the main reservoir of reactive nutrients so their complete management is very crucial so as to address the worldwide food security challenges and reduce the environmental losses which affect the quality of water and air. There are various risks related to soil such as soil compaction, acidification, erosion, contamination, salinization and decline of organic matter that affects Phosphorus and Nitrogen losses to water and air.
- Physico chemical properties of soil
The continuous utilisation of chemical fertilizers affects the soil biochemical properties that results in the shifting of microbial population. The alteration in Nitrogen content, moisture, pH and availability of nutrients to the microbes has been observed as a result of increased use of fertilizer in different crops such as corn, wheat and others. It has also declined the bulk density of soil that is due to the increase in organic carbon of the soil.
- Soil Enzyme Activity
The various soil enzymes are the indicators of soil fertility and microbial activity but the long term application of chemical fertiliser has no serious and positive impact on the microbial biomass and dehydrogenase activity, while organic fertilizer has some positive impact.
- Soil Compaction
This occurs due to low use of organic fertiliser, heavy machinery use, constant use of chemical Fertiliser and continual plowing at a constant depth. Compaction of soil causes many problems such as inadequate erosion, extreme soil strength poor drainage, erosion, run off, and soil degradations and these leads to the decrease in permeability, hydraulic conductivity and groundwater recharge.
- Soil Acidification
The acidity of the soil is the concentration of hydrogen ions in the solution and acid soils are that soils that have pH levels below 7. The constant and enormous application of Nitrogen fertilizers tends to generate hydrogen ions and which results in the loss of soil nutrients, replacing the alkaline elements on the exchange sites. The free oxygen produced in the reaction oxidizes the organic matter causing it to combust at low levels in the soil. Some of the ammonium dependent fertilizers cause soil acidification as they produce two hydrogen ions for each molecule of ammonia nitrified to nitrate. Nitrogen fixing bacteria and free living fungi are also responsible for the high levels of Nitrogen and microbial community changes which influence various soil processes such as nutrient cycling and mineralisation of the organic matter.
- Effect on soil biodata
The microbial activity of the soil is a vital part of soil health. Some of the biotic organisms such as bacteria, fungi, protozoa, algae and viruses constitute the soil microFlora which is an important part of the agricultural system and they have many essential and basic roles in the soil such as soil fertility, nutrient cycling, enhancing productivity and degradation of inorganic as well as organic matter.
- Soil salinity
The major content of chemical fertilizers are salts which are believed to be very destructive in Agriculture as they damage the soil and plants and the dissolution of chemical fertilizer applied to the soil may affect many soil properties particularly salinity.
- Effect on plants
The fertility of soil and vegetation are highly dependent upon the sufficient supply of essential Minerals and nutrients, but when these nutrients are provided in excess amounts, it causes soil nutrient supply imbalance that leads to deterioration of stable soil.
Chemical fertilizers help the plants to grow quickly but the plants growing this way have little time to develop the proper root growth and become incapable of making their stems strong or nutritious vegetables and fruits.
The chances of their survival are likely lower and they also become susceptible to diseases and pests. The chemical fertilizers impede sufficient water intake for the plants which results in root burning or fertilizer burning.
Fertilizer use is seen as a Technology needed for agriculture but the long term application of chemical fertilizers has a negative impact on the physico chemical properties and soil biological properties. These fertilizers disrupt the microorganisms and it also influences the structural and functional diversity.
The soil reaction and electrical conductivity are also influenced by inorganic fertilizer addition. The NPK fertilizer application reduces the functions of various soil enzymes. Chemical fertilizers are important and it should be applied in due time and in appropriate quantities, but after examining the soil carefully.
The chemical content and the structure of soil should be understood and the most effective fertilizer should be used for it. Also, a correct method of fertilization should be applied otherwise it can lead to loss of both finance, time and energy.