Vel Tech High Tech Dr.Rangarajan Dr.Sakunthala Engineering College Department of Chemical Engineering CH6605- Fertilizer Technology UNIT- I NITROGENOUS FERTILISERS PART – A 1. What is a Fertilizer? What is the need for fertilizers? (May/June 2009) A fertilizer may be defined as an extraneous material provided for the cultivable land in order to supplement the nutrition the crops and trees etc. can draw from the land. It can be defined as the quantity of additional nutrients required by a particular crop to increase its growth to the optimal level in a given soil. Fertilizer is generally write "any material, organic or inorganic, natural or synthetic, which supplies one or more of the chemical elements required for the plant growth". 2. Define Fertilizer Grade. All fertilizer labels have three bold numbers. The first number is the amount of nitrogen (N), the second number is the amount of phosphate (P2O5) and the third number is the amount of potash (K2O). These three numbers represent the primary nutrients (nitrogen (N) - phosphorus (P) - potassium (K)). This label, known as the fertilizer grade, is a national standard. A bag of 10-10-10 fertilizer contains 10 percent nitrogen, 10 percent phosphate and 10 percent potash. 3. What is Straight Fertilizer? Straight fertilizer is a fertilizer that contribute single nutrient to the crops. Straight fertilizers are those which supply only one primary plant nutrient, namely nitrogen or phosphorus or potassium. eg. Urea, ammonium sulphate, potassium chloride and potassium sulphate. 4. State the function of nitrogen in nitrogenous fertilizer. (Nov/Dec 2011) Nitrogen supplied as nitrate ion or ammonium salt is one of the important constituent for synthesis of amino acids which are then converted into proteins and enzymes. Proteins thus formed make part of the protoplasm, while enzymes act as catalysts for various reactions taking place in the plants. Nitrogen is also a special constituent of the chlorophyll, without which photosynthesis is not possible. Nitrogen makes up 16-18% of the plant protein and constitutes 1-4% of the dry weight of plants and is required in large amounts of any of the plant nutrients. Sources of nitrogen Atmosphere Organic nitrogen compounds formed in the soil by recurring natural processes Fertilizers 5. What is the need for fertilizers? It can be defined as the quantity of additional nutrients required by a particular crop to increase its growth to the optimal level in a given soil. Fertilizing the land is essential due to following reason Provide nutrient essential for growth and better yield. Maintain the pH of the soil in the vicinity of 7-8 to facilitate optimum growth Provide food supplement to the plants 6. What are nitrogenous fertilizers produced from the ammonia? (Apr/May 2015) Ammonium sulphate, ammonium nitrate, urea, calcium ammonium nitrate and ammonium chloride 7. What are the Chief requisites of a fertilizer? State them (April/May 2011) (May/June 2013) • Must be soluble in water • The element present in the • Should not be toxic to plant • Should be cheap compound must be easily • Should be stable for long • Should maintain the pH of the soil in available to the plant time the vicinity of 7 to 8. 1 | P a g e Vel Tech High Tech Dr.Rangarajan Dr.Sakunthala Engineering College Department of Chemical Engineering CH6605- Fertilizer Technology 8. How are fertilizers classified? (April/May 2011) Based on their Based on the source Based on their Based on the physical chemical nutrient content state composition Organic products a) Natural organic fertilizers Micronutrient Solid fertilizer: Mineral fertilizers Animal matter: fertilizers: Liquid fertilizers: Synthetic soil Farm yard manures: Straight fertilizers: conditioners Guano Compound fertilizer: Plant matter: (complex or multi- nutrient fertilizers) b) Natural inorganic fertilizers Rock Phosphates: Chile Saltpetre: Potassium Salts: c) Artificial fertilizers Phosphorus fertilizer Nitrogenous fertilizer Potassium fertilizer 9. Define Fertilizer ratio Commercial fertilizer has specific ratio of nutrients, or fertilizer ratio or plant food ratio. It is the ratio of the number of fertilizer units in a given mass of fertilizer expressed in the order N, P and K. Thus, it is the ratio of two or more nutrient percentages to one another. For instance, a fertilizer with 5-10-15 grade has 1-2-3 ratio, whereas a fertilizer with 10-20-20 grade has 1-2-2 ratio. Fertilizer ratio is also defined as the relative proportion of primary nutrients in a fertilizer grade divided by the highest common denominator for the grade. For example, the grade 16-12-20 has a ratio of 4-3-5 of N, P and K, respectively. 10. Write the benefits of a fertilizer. The fertilizer benefits to the human environment are as follows a) Farming efficiency improvement b) Improvement of soil quality with adequate fertilization c) Crop quality improvement d) Water conservation 11. Classification of Elements Essential for Plant Growth • Major elements - (Available from air or water) Carbon, Hydrogen, Oxygen (Macronutrients) - Primary nutrients Nitrogen Phosphorus, Potassium - Secondary nutrients Calcium Magnesium, Sulfur • Minor elements (Micronutrients) Boron, Chlorine, Copper, Iron, Manganese, Molybdenum, Zinc 2 | P a g e Vel Tech High Tech Dr.Rangarajan Dr.Sakunthala Engineering College Department of Chemical Engineering CH6605- Fertilizer Technology 12. Differentiate between primary nutrients and secondary nutrients. (April/May 2008) Primary nutrients Nitrogen, phosphorus and potassium are consumed in large amounts by the plants for their growth and so these are called primary nutrients. Secondary nutrient Calcium, magnesium and sulfur which occur to a limited extent in all soils, are called secondary nutrients. 13. Distinguish between direct and indirect fertilizers. (April/May2010), (Nov/Dec 2011) Direct Fertilizers A material that can serve the purpose of providing nutrition to plants, trees and crops by easily getting assimilated by the land, can be termed as direct fertilizer. For Sample super phosphates, nitrates and ammonium compounds. Indirect Fertilizers These fertilizers are used to improve the mechanical, chemical and biological properties of the soil. Fertilizers used to change the reaction of the soil solution, to improve the physical properties of the soil, and to activate its useful microflora. For example dolomite, limestones are used to reduce the soil acidities and gypsum used to improve the properties of the soil with a high salt content. 14. State the important characteristics of nitrogenous fertilizers. (May/June 2013) They are readily soluble in water and easily decomposed by micro organisms in the soil. In the soil, they are quickly changed into ammonical and then nitrate form and becomes available to the plants. Main amide fertilizers used in our country Urea -46%, Calcium cynamid -21%N. 15. What is organic Manure? Organic waste matter- food waste, deceased animal parts, animal excreta etc. can be composed together with mud and slime to form a good natural fertilizer material for crops. Such material is called organic manure. Before the invention of chemical Fertilizers farmers in our country were dependent on organic manure only. 16. What are the Advantages of Organic Fertilizer? • Improve the structure of • Release nitrogen slowly • Do not burn the plants like the soil and consistently. some chemical fertilizers • Retain soil moisture • Mobilize existing soil • Less subject to leaching nutrients. 17. How are urea prills made? Solid urea is the largest nitrogen fertilizer product which is produced in two forms of granules and prills. It is concluded that the urea prilling process is the finishing process which produces the weaker and the more uniform size and strength of the particles than the fluidized-bed granulation process. 18. Why is urea prilled? (April 2016) A prill is a small aggregate or globule of a material, most often a dry sphere, formed from a melted liquid. Prilled is a term used in mining and manufacturing to refer to a product that has been pelletized. The pellets are a neater, simpler form for handling, with reduced dust. The material to be prilled must be in a solid state at room temperature and a low-viscosity liquid when melted. Prills are formed by allowing drops of the melted prill substance to congeal or freeze in mid-air after being dripped from the top of a tall prilling tower. Certain agrochemicals such as urea are often supplied in prilled form. Fertilizers (ammonium nitrate, urea, NPK fertilizer) and some detergent powders are commonly manufactured as prills. 3 | P a g e Vel Tech High Tech Dr.Rangarajan Dr.Sakunthala Engineering College Department of Chemical Engineering CH6605- Fertilizer Technology 20. What is biuret and what is its fertilizer value? (April 2016) Biuret is a chemical compound with the chemical formula C2H5N3O2. It is also known as carbamylurea. It is the result of condensation of two molecules of urea and is an impurity in urea-based fertilizers. The parent compound can be prepared by heating urea above the melting point at which temperature ammonia is expelled: 2 NH2CONH2 → NH2CONHCONH2 + NH3 UREA BIURET 21. How does urea act as a fertilizer? (April/May 2008) Urea is an inexpensive form of nitrogen fertilizer with an NPK (nitrogen-phosphorus- potassium) ratio of 46-0-0.Urea will provide the most nitrogen at the lowest cost. It is easy to store and does not pose as a fire risk for long-term storage. Urea may be mixed with other fertilizers or may be applied on its own. For plants that love acidic soils, urea is one of the top fertilizers for acidifying soils. For gardeners who grow crops like corn, strawberries, blueberries and other heavy nitrogen feeders, urea will supply immediate and powerful applications of nitrogen. 22. Illustrate the chemical reaction involved in the production of ammonium sulphate. (Nov/Dec 2017) Method of production a)As by-product from caprolactam b) Recovery from cock oven c) Direct neutralization 2NH3 + H2SO4 (NH4)2 SO4 d) Gypsum process 23.