AGRICULTURAL FERTILIZERS

      Fertilizers provide nutrients to the soil to help plants grow. Fertilizers are chemical substances that are used to enrich soils with specific nutrients to help plants grow. The elements provided by fertilizers are typically nitrogen, phosphorus and potassium, although other elements such as calcium and sulfur are also available within certain commercial fertilizers. When applied to the soil, fertilizers break down into these constituent components and are then absorbed through the root systems of plants as a form of nourishment.

    The primary nutrients that plants of all kinds need are nitrogen, potassium and phosphorus. Nutrient-poor soil will negatively affect the health of your plant. In order to rejuvenate your plant's health, adding fertilizer to the soil will balance the soil's nutrients. Since the vast array of plants that exist have unique needs, "amending," or adding fertilizer to your soil, varies from plant to plant. Try to understand the differences among fertilizers to help make decisions more successful.

Organic

    Fertilize your garden with compost. 

    Organic fertilizers are those that are natural and contain no chemicals. Organic fertilizers are made up of animal and plant by-products, such as manure or composted food waste. Fertilizers that are completely organic tend to be high in nitrogen and are a good source of nutrients for soil and plants. Fertilizer high in nitrogen can help balance the pH levels within soil.

Inorganic

    Inorganic fertilizers have been artificially synthesized through the use of chemicals. Commercial fertilizers bought in a store will most likely be inorganic. Inorganic fertilizers are available in granules, powder or liquid form.. This type of fertilizer is also a good source of nutrients for plants and is easy to transport.

Plant Specific

    Different plants need different ratios of nutrients. While one plant may need more nitrogen to thrive, another may need more potassium. When you are caring for a plant with particular needs, a plant specific fertilizer offers you the option of a preset ratio of nutrients based both on the plant and the climate where it grows.

Time Release

    Use fertilizers that release nutrients at controlled intervals of time. 

    For some plants, too many nutrients at once can be harmful instead of helpful. Depending on your plants' needs, time release fertilizers release nutrients at steady intervals so your plants receive the nutrients they need on a regular basis. Controlled-release or slow-release fertilizers may allow you to attain more effective care of your garden since you will not have to feed your plants as often.

Liquid

    Liquid fertilizers make it possible to deliver a concentrated amount of nutrients to specific plants. Since the liquid fertilizer cannot be added into soil the way organic, powder, or granules can (it cannot assimilate in widespread areas), you can more efficiently decide which plants need specific, case-by-case doses.

Fertilizer with Pesticide

    Whether your plants are being attacked by pests or are a target for wildlife, using a fertilizer with a pesticide takes care of two problems with one solution. The fertilizer delivers the nutrients your plants need to remain healthy while deterring present or future harmful pests.

Urea

    Urea is the most widely used solid nitrogen fertilizer and is usually applied as granules, although it is sometimes mixed with ammonium nitrate and dissolved in water to form urea ammonium nitrate solution. When applied to soil, urea reacts with water to form ammonia, which makes the nitrogen within the fertilizer available to plants. Urea fertilizers deliver one of the highest amounts of nitrogen at 46 percent, with no phosphorus or potassium.

Ammonium Nitrate

    A solid fertilizer typically applied in granular form, ammonium nitrate provides substantial amounts of nitrogen to the soil. The Fertilizer Institute indicates that ammonium nitrate is particularly effective at fertilizing specialty crops such as citrus and pasture lands. Ammonium nitrate typically provides 33 percent nitrogen.

Ammonium Sulfate

    A by-product derived from the waste generated by coke ovens, ammonium sulfate forms when sulfuric acid is used to remove ammonia from the coal used to make coke. Ammonium sulfate is a solid material that contains 21 percent nitrogen.

Calcium Nitrate

    This fertilizer contains 16 percent nitrogen in a nitrate form. Less effective than other nitrogen fertilizers due to leaching when applied to soil, calcium nitrate is often used in fruit and vegetable crops to provide a readily available source of nitrogen and also provides soluble calcium for soils that are calcium deficient.

Diammonium Phosphate

    Where soils do not have enough phosphorus, diammonium phosphate can provide significant amounts of this chemical, at around 46 percent. The ammonia component of diammonium phosphate also delivers around 18 percent nitrogen. Highly water soluble, diammonium phosphate is often applied in liquid form.

Monoammonium phosphate

    Another phosphorus fertilizer, monoammonium phosphate delivers even more phosphorus than diammonium phosphate, at 48 percent. The amount of nitrogen in fertilizer provides is somewhat less at 11 percent. The lower level of the ammonia component of this chemical lessens the risk of damage when applied to new seedling growth.

Potassium Nitrate

    Potassium nitrate, also called nitrate of potash, is frequently used on vegetable crops including celery, potatoes, leafy green vegetables, tomatoes and several fruit crops, according to the Michigan State University Extension. The nitrate component of this chemical fertilizer works well with these crops. Potassium nitrate provides 44 percent potassium.

Potassium Chloride

    Sometimes called muriate of potash, potassium chloride is a significant source of the element potassium as a fertilizer. Directly applied to soils or combined into multiple endings of mixed fertilizers, potassium chloride is also highly soluble and can be applied in liquid fertilizers. The chemical typically provides 60 to 62 percent potassium.

Advantages of Agricultural fertilizers

•    The usage of the enhanced and modified fertilizers leads to a massive increase in agricultural productivity and net output. It strengthens the soil and enhances its fertility.

•    There are numerous crops and plants which have different growing habits and nutrient requirements. the fertilizers help us in understanding the precise needs and requirements of the plants fulfilling which maximum production can be reached.

•    The blended mixtures of measured quantities of the nutrients enables the plants to get potential nutrition and help them to hasten growth and yield more than their usual capacity.

•    The fertilizers are highly soluble and do not take much time to get dissolved in the soil and reach the plant in no time. However it happens only in the case of chemical fertilizers and organic fertilizers take time to be dissolved.

    Moreover, agricultural fertilizers are a combination of hazardous and beneficial fertilizers. Organic fertilizers are not as harmful as the inorganic ones however the former takes more time than the latter top reach the roots of the concerned plants. Excessive fertilization does encourage great yields however also invites air, water and soil pollution. Therefore it is very necessary to use fertilizers in limited quantities and if possible then organic and inorganic should be used simultaneously to counterattack the miscellaneous soil hazards.

Disadvantages

•    Eutrophication: Overgrowth of aquatic vegetation and degradation of water quality due to extra nitrogen accumulation

•    Increased acidity: Many chemical fertilizers are composed of acids like sulphuric acid and hydrochloric acid and these acids decrease the soil's quality and heightens the acidity which further registers a bad impact on the plant growth.

•    Loss of bacteria: The natural nitrogen fixing bacteria, rhizobium suffers great blows from the excessive usage of chemical bacteria.

    Certain plants are hampered due to excessive dozes of the chemical fertilizers so much so that they also tend to cease growing and yield fruits. However, organic fertilizer might work slower but they leave an everlasting impact on the soil texture and improves the water holding capacity of the soil, regains its fertility and prevents soil erosion.

Read more

http://www.ehow.com/list_7421086_list-common-agricultural-fertilizers.html
http://www.epa.gov/agriculture/tfer.html
http://www.agriculturalproductsindia.com/fertilizers/fertilizers-chemical-fertilizer.html