Chemistry
NPK Fertilisers
NPK fertilizers are a type of fertilizer containing three primary nutrients: nitrogen (N), phosphorus (P), and potassium (K). These nutrients are essential for plant growth and are typically found in varying ratios in NPK fertilizers. Nitrogen supports leaf and stem growth, phosphorus aids in root development and flower/fruit production, and potassium helps with overall plant health and disease resistance.
Written by Perlego with AI-assistance
Related key terms
1 of 5
10 Key excerpts on "NPK Fertilisers"
eBook - PDF- Sharma, Ramniwas(Authors)
- 2021(Publication Date)
- Biotech(Publisher)
Fertilisers are not plant food! Although it is common for many fertilisers to be called plant food, it is a misnomer. Plants produce their own food using water, carbon dioxide and energy from the sun. This food (sugars and carbohydrates) is combined with the plant nutrients to produce protein, enzymes, vitamins and other elements essential to plant growth. D IFFERENT T YPES OF F ERTILISERS Of the 16 essential elements for plant growth, nitrogen, phosphorus and potassium are considered fertiliser macronutrients because plants require them in larger quantities for maximum growth. Common incomplete fertilisers or farm type fertilisers. % Nitrogen % Phosphorus % Potassium Ammonium nitrate 33 0 0 Ammonium sulfate 21 0 0 Mono-ammonium phosph 11 52 0 Muriate of potash 0 0 60 (potassium chloride) Potassium sulfate 0 0 52 Super phosphate 0 20 0 Triple super phosphate 0 46 0 Urea 42-45 0 0 Diamonium phosphate 18 46 0 Slow Release Urea-formaldehyde 38 0 0 Sulfur-coated urea 22-17 0 0 IIBDU 31 0 0 Calcium, magnesium and sulfur are secondary macronutrients, but they are usually either present in sufficient quantities, or they are added coincidentally with other materials. The other essential elements, called micronutrients, are just as important This ebook is exclusively for this university only. Cannot be resold/distributed. 26 M ECHANISMS OF P LANT F ERTILISATION but are required in smaller amounts. If plants lack any of these elements, they exhibit signs of nutrient deficiency. F ERTILISER A NALYSIS The fertiliser analysis on the bag refers to how much of an element there is in a formulation based on percentage of weight. All fertilisers are labeled with three numbers that give the percentage by weight of nitrogen (N), phosphate (P 2 O 5 ) and potash (K 2 O). Often, to simplify matters, these numbers are said to represent nitrogen, phosphorus, and potassium, or N-P-K. We should remember that it is not N-P-K but N-P 2 O 5 -K 2 O.
eBook - PDF- Rattan Lal, B.A. Stewart(Authors)
- 2010(Publication Date)
- CRC Press(Publisher)
121 6.4.3.2 Fertilizers from Mineral Phosphates ................................. 122 6.4.4 Potassium Salts ................................................................................. 124 6.4.4.1 Potassium Minerals ............................................................ 125 6.4.4.2 Potassium-Magnesium Minerals ....................................... 125 6.4.5 Overview of the Fertilizer Industry .................................................. 126 6.5 Energy, Fuel, and Price of Fertilizers ........................................................... 130 6.6 Fertilizer and the Environment ..................................................................... 131 References .............................................................................................................. 135 6.1 In t r o d u Ct Io n Fertilizers provide plants with the nutrients they need for growth and development. Plants live, grow, and reproduce by taking up water and nutrients, carbon dioxide from the air, and energy from the sun. Apart from carbon, hydrogen, and oxygen, which collectively make up 90–95% of the dry matter of all plants, other nutrients 110 Food Security and Soil Quality needed by plants come essentially from the media in which they grow—essentially the soil. The other nutrients are subdivided into primary nutrients (nitrogen, phos-phorus, and potassium) and secondary nutrients (calcium, magnesium, and sulfur). In addition, plants also need other nutrients in much smaller amounts, and they are referred to as micronutrients (boron, chlorine, copper, iron, manganese, molybde-num, and zinc). To maintain soil fertility and productivity and prevent land degradation, nutrients taken up by crops must be replenished through the application of fertilizers.
- F.B Lewu, Tatiana Volova, Sabu Thomas, R.K. Rakhimol, Rakhimol K R(Authors)
- 2020(Publication Date)
- Academic Press(Publisher)
56 ].Most of the inorganic fertilizers influencing the growth and development of plants are NPK fertilizers that are rich in macronutrients nitrogen (N), phosphorus (P), and potassium (K). Moreover fertilizers also supplement minor nutrients like calcium, sulfur, magnesium to enhance the soil fertility. The fertilizer industries are the major contributors of outdoor terrestrial natural radionuclides ( 238 U, 232 Th, and 210 Po) and heavy metals (Hg, Cd, As, Pb, Cu, Ni, and Cu) as potential sources [22 ,57 ]. The factory workers associated with the production of fertilizers and farmers involved in direct application of fertilizers are exposed to ionizing radiations from these radionuclides. The long-term exposure of such radiations released from fertilizers has a potential to trigger cancers in humans [57 ]; hence, international awareness about such radiation hazards should be taken into consideration.Over the past decades, chemical fertilization increased exponentially throughout the world causing serious environmental pollution and health hazards. This leads to the deterioration of soils' natural properties and fertility, accumulation of heavy metals in plant tissues, compromising the nutritional value of fruits and other crops [55 ]. Although chemical/synthetic fertilizers have been claimed to be the most important contributor to the world's agricultural productivity [58 ], their negative effects on environment and humans limit its usage in sustainable agricultural systems [47 ]. Hence, it is mandatory to gain a detailed knowledge about the chemistry and journey of agropollutants from soils to ecosystems and from crops to its dependent food chains via absorption from soil. These toxic agropollutants persist in the soil and leach into water sources causing serious environmental issues like increasing the rate of eutrophication, loss of biodiversity, ozone layer depletion, global warming, ground water pollution, and threatening of the future food security, thus, leading to health problems [10
Thanks to legislation going back to the Fertilizers and Feedstuffs Act in the late 1800s, anything sold as a fertilizer has to have its content in terms of percentage plant nutrients prominently displayed, and the major nutrients always listed in the order NPK. When reading the label on a pack of tomato fertilizer, however, it appears that there is more to this than initially meets the eye. Thus the element nitrogen is frequently provided in three forms: nitrate, urea or ammonia. Depending on the fertilizer, it may contain nitrogen in just one or all three of these forms, in which case the label will give a percentage figure for total nitrogen, plus an additional breakdown of the components.The content of the element phosphorus is expressed in terms of phosphorus pentoxide soluble in water; potassium content is expressed in the form of potassium oxide. If included, the minor and trace nutrients are usually listed just using their chemical symbol. The major nutrients are also expressed in ratio form, which allows easy comparisons between different fertilizer brands. For example, the old allotment favourite National Growmore (introduced as part of the ‘Dig for Victory’ campaign, and still going strong) is a general purpose compound fertilizer containing 7 per cent N, 7 per cent P and 7 per cent K. This is also known as a 1:1:1, describing the ratio of nutrients to each other.The requirement for mineral nutrients differs according to both the plant and the plant’s stage of development. Back in the 1920s it was shown that in one season a greenhouse-grown tomato crop extracted four and a half times the amount of nitrogen from the soil than phosphate, and a massive nine times the amount of potassium.Before concluding that the ideal tomato fertilizer should contain nutrients in these ratios, it should be noted that much of the nitrogen is needed in the initial vegetative growth stage, whereas most of the potassium is used when the plants are bearing heavy loads of fruit. This gives a case for using two different fertilizer combinations, one higher in nitrogen for the early stages of the crop, followed by one higher in potassium for the main fruiting season.
eBook - ePub- Allen V. Barker(Author)
- 2021(Publication Date)
- CRC Press(Publisher)
Severe shortages of nutrients usually lead to the development of symptoms of deficiency. Recognition of these symptoms is a useful way of identifying nutritional disorders in a crop. If the deficiency is detected in time, fertilization may restore crop productivity. If the deficiency is recognized too late for correction in the current crop, the grower is alerted that remedies need to be taken for the next season.Fertilizers are materials that carry plant nutrients to the soil or directly to crops. This chapter will present and evaluate organic and chemical fertilizers for each of the plant nutrients and will discuss practices that increase the nutrient-supplying capacity of soil.Nitrogen
Functions
The discovery of the essentiality of nitrogen is attributed to Theodore de Saussure, who in 1804 published his research that showed that normal growth of plants was not possible without the absorption of nitrates and other minerals from the soil. Nitrogen has many functions in plants. It is a component of proteins, genetic material (the nucleic acids, DNA and RNA), chlorophyll, and many other compounds that are vital in plant metabolism. Proteins are nitrogen-rich compounds and are major nitrogenous constituents of plants. By weight, about one part in six (16%) of the average protein molecule is nitrogen. About 85% or more of the nitrogen in plants is in protein. Another 10% of the total nitrogen in plants is in soluble nitrogenous compounds, such as uncombined amino acids and unassimilated nitrate and ammonium. The remaining 5% or less of the total nitrogen is in the genetic material, chlorophyll, coenzymes of metabolism (vitamins and the like), and lipids, among other compounds.Effects of Nitrogen on Plant Growth and Quality
Nitrogen is a potent nutrient, the deficiency of which can limit crop production severely. Application of nitrogen fertilizers must be monitored closely to avoid under-fertilization or over-fertilization. Nitrogen is deficient in about 70% of crop land. Recovery of growth and yield potential from nitrogen deficiency during resupply of the nutrient can be rapid; however, over-application of nitrogen may have adverse effects on growth and quality. Some of the effects of limited, optimum, and excessive nitrogen fertilization follow.
eBook - ePub- Boyd Ellis, Henry Foth(Authors)
- 2018(Publication Date)
- CRC Press(Publisher)
11 Nitrogen, Phosphorus, and Potassium FertilizersThe fertilizer industry developed in stages with phosphate materials in the 1840s, potassium materials in the 1870s, and the nitrogen materials about 1900. More recently, micronutrient fertilizers have been developed.Overall soil fertility in the U.S. has been increasing, and in many Instances the application of only one nutrient is desirable. Improvements and greater use of soil tests have helped identify these situations. As a result, the use of single-nutrient carriers for direct application to the soil, relative to use of mixtures, has been increasing. Actually, the application of both kinds of fertilizers have been increasing. In 1976, the direct application of single carrier fertilizers surpassed the use of mixtures or mixed fertilizers.11.1 NITROGEN FERTILIZERSManure was the dominant fertilizer for thousands of years in areas where animals were used for power and food. Most of the nutrients in feed appear in the manure, and If the manure is efficiently managed, it can be very effective in the maintenance of soil fertility. Peruvian guano was the first fertilizer imported into the U.S. In 1824. This organic fertilizer consisted of the excreta and remains of birds whose primary diet consisted of fish. Guano contains about 13% N, which is mostly organic. In 1830, NaNO3 was imported from Chile. This inorganic material of natural origin contains about 16% N. These materials were used in the southern U.S. largely on specialty crops, such as cotton and tobacco. In the 19th century, the byproduct NH3 produced from the coking of coal used in steel manufacturing was neutralized with H2 SO4 to produce (NH4 )2 SO4 .11.1.1 The Major Nitrogen CarriersEconomics drives the production of N fertilizers toward the material or carrier that supplies N at the least cost. This carrier is anhydrous ammonia, NH3 , which contains 82% N. Its cost advantage is due to both low costs in production and in transportation, for NH3 is transported by pipeline. Two large pipelines transport NH3 from plants in Louisiana, Texas, and Arkansas to terminals as far west as Aurora, Nebraska, as far north as Garner, Iowa, and as far east as Huntington, Indiana. In 1965, NH4 NO3 was the second most popular carrier and urea was third. By 1978, there was greater consumption of urea than of NH4 NO3 in the U.S. These three carriers are the basis for making N solutions, which have increased steadily since 1965. These trends are shown in Figure 11.1 . Today, 95% or more of the N in fertilizers is produced by direct synthesis of NH3
eBook - ePub- Neal S. Eash, Thomas J. Sauer, Deb O'Dell, Evah Odoi, Mary C. Bratz(Authors)
- 2015(Publication Date)
- Wiley-Blackwell(Publisher)
Chapter 8 Soil Fertility and Plant NutritionWater, carbon dioxide, and certain chemical elements called plant nutrients are essential for plant growth. Water is supplied by either rainfall or irrigation, carbon dioxide from the atmosphere, and the essential plant nutrients from the soil, fertilizers, or other soil amendments.Soil Fertility
Soil fertility includes the ability of a soil to hold plant nutrients, the level of plant nutrients present, and the availability of the nutrients for uptake by plants. A soil that has a high level of essential nutrients available for use by plants is usually a productive soil if it also has sufficient soil water and if the crops are well managed. Plant nutrients exist in the soil in several different forms. They include the following:- Minerals. Examples include the feldspar group, which is the most abundant group of minerals in the rocks of the earth. Some are high in potassium and others in calcium. Nutrients are released from the minerals by weathering.
- Cations or anions. These are plant nutrients that exist on the surface of clay or humus. These surfaces are called the exchange complex and are positive or negative. They attract, hold, and exchange the cations or anions (see Chapter 5 ).
- Chemical compounds. There are many chemical compounds that form in the soil. An example would be the formation of phosphorus complexes on the surface of calcium carbonate.
- Soluble ions. Numerous ions exist in the soil solution. Plants absorb a large portion of their essential nutrients from this source. This pool of nutrients is small, but can be readily replenished through cation exchange reactions and other buffering mechanisms.
- Organic matter
- Alison Samuel, Louisa Dines, Steve Finch, Gerry P. Lane, A M Samuel(Authors)
- 2022(Publication Date)
- Woodhead Publishing(Publisher)
4: Fertilisers and manures
Abstract
This chapter explains the importance of optimising plant nutrition and soil fertility for crop production. It discusses the main plant food elements required by crops, both major nutrients and micronutrients (trace elements). It describes the fertiliser materials used on-farm and explains the differences between straights, compounds, complexes and blends, as well as considering application practices and methods for both solid and liquid fertilisers. Organic materials, both produced on- and off-farm are valuable nutrient sources for crop production and can often be additionally beneficial as soil conditioning agents. Livestock manures and slurries, together with a range of other organic materials, are described in terms of their characteristics and best use. Finally, the chapter considers the effect of fertilisers and manures on the wider environment.Keywords
Compound; Fertiliser; Nitrogen; Nutrient; Organic material; Phosphorus; Potassium; Straight4.1. Introduction
Good nutrient management is a key aspect of viable and sustainable agricultural production. There is the challenge of increasing food production for the growing global population whilst ensuring that environmental impacts are lessened. Supplying optimal levels of nutrients for crop and livestock production as part of profitable farming businesses involves extensive decision making associated with the importance of integrated farming systems and their connection with the wider environment including the abiotic considerations of soil, water and air linked to the biotic aspects of habitats, biodiversity and species.For viable field crop production, in terms of economic yield and good crop quality, nutrients should be readily available so that uptake is optimised and both nutrient deficits limiting uptake and nutrient excesses that may cause losses to the environment are reduced. Nutrient removals off the field as a result of crop harvest should be considered in nutrient budgeting calculations and decisions so that nutrient inputs help to reduce any nutrient gaps in the system and soil available nutrient levels are maintained at an optimum level that suit both effective cropping and a better environment. An assessment of nutrient budgeting considers at a basic level both crop nutrient supply and harvest offtake, but in more detailed assessments can include all nutrient additions to the soil supplying the crop and all nutrient outputs including to the wider environment away from the crop. It is important that any nutrient supply system minimises the loss of nutrients to the environment as well as avoiding either a deficiency or an excess of individual, required nutrient elements. There are additional factors associated with local soil characteristics, nutrient behaviour and effects of weather and climate that should also be part of any nutrient decision-making process.
eBook - PDF- Roksana Khalid(Author)
- 2019(Publication Date)
- Delve Publishing(Publisher)
128 4.15. The Nitrogen Cycle ....................................................................... 129 4.16. The Phosphorus Cycle ................................................................... 132 4.17. The Potassium Cycle ..................................................................... 133 4.18. Role Of Nutrients And Minerals In Plant Cycling .......................... 134 4.19. Diagnosing Nutrient Toxicities ...................................................... 138 References ............................................................................................. 141 Handbook of Minerals and Nutrients 104 4.1. BACKGROUND Similar to every other living organism, plants also require food and nutrients for their development and growth. Plants mainly require 16 vital mineral elements. Oxygen, hydrogen and carbon are derived from the soil, water and atmosphere. The other 13 essential minerals (nitrogen, phosphorus, potassium, calcium, magnesium, Sulphur, iron, zinc, manganese, copper, boron, molybdenum, and chlorine) are obtained from soil minerals, organic soil matter and fertilizers (both organic and inorganic). An adequate supply of light, water and heat are compulsory for efficient utilization of nutrients in plants. Cultural practices for control of insects and diseases also play significant roles in the efficient production of crops (Aber & Melillo, 1991; Andrews et al., 2013). Every variety of the plants possesses some unique characteristics with a necessity to utilize an optimum range of nutrients. However, nutrients’ intake below a certain level results in nutrition deficiency which may even lead to drying of leaves. On the other hand, excessive uptake of nutrients can also result in toxicity and poor growth. Therefore, the sufficient levels of minerals and their proper placement is extremely important. Various test methods have been developing to determine the true mineral content in soil and plant tissues.
eBook - PDF- Jaga, Praveen Kumar(Authors)
- 2021(Publication Date)
- Daya Publishing House(Publisher)
Principles of efficient use of fertilizers: The principles of efficient use of fertilizers are 1) selection of fertilizers 2) proper time of application of fertilizers 3) use of suitable amount of fertilizers 4) correct method of application of fertilizers. 1. Selection of fertilizers : Correct selection of fertilizers depends on the following factors. (i) Physical and chemical properties of soil: Due to excess leaching in light soil nitrate fertilizers should not be added. Fertilizers producing acidity as ammonium sulphate should not be added in acidic soil. Water soluble phosphatic fertilizers as super phosphate should not be added in acid soil because they are readily fixed in soil. Alkalinity producing fertilizers like sodium nitrate should not be added in alkali soil. (ii) Climate : In high rainfall area ammonical fertilizers should be added in soil because the leaching loss is less, whereas nitrate fertilizers can easily be applied in soil where rainfall is low. (iii) Crop requirement : Ammonical nitrogen is better than nitrate nitrogen in paddy crop where as some crop like tobacco, linseed etc are very sensitive to chloride; hence fertilizers containing chloride should not be added in soil. When crops require excess sulphur i.e. ground nut oilseed crops, pulse crops etc sulphur containing fertilizers like gypsum, ammonium sulphate should be added in soil. (iv) Unit cost of nutrients -The fertilizers having minimum nutrient unit cost value should be applied in soil. 2. Proper time of application of fertilizers: F ollowing factor affect the correct time of application of fertilizers-(i) Soil type : Nitrogenous fertilizers should be added in two or three splits doses in soils having less water holding capacity. This ebook is exclusively for this university only. Cannot be resold/distributed.
Index pages curate the most relevant extracts from our library of academic textbooks. They’ve been created using an in-house natural language model (NLM), each adding context and meaning to key research topics.
