Agricultural chemistry is the chemistry, especially organic chemistry and biochemistry, as they relate to agriculture. Agricultural chemistry embraces the structures and chemical reactions relevant in the production, protection, and use of crops and livestock. Its applied science and technology aspects are directed towards increasing yields and improving quality, which comes with multiple advantages and disadvantages. [1]
This aspect of agricultural chemistry deals with the role of molecular chemistry in agriculture as well as the negative consequences.
Plant biochemistry encompasses the chemical reactions that occur within plants. In principle, knowledge at a molecular level informs technologies for providing food. Particular focus is on the biochemical differences between plants and other organisms as well as the differences within the plant kingdom, such as dicotyledons vs monocotyledons, gymnosperms vs angiosperms, C2- vs C4-fixers, etc.
Chemical materials developed to assist in the production of food, feed, and fiber include herbicides, insecticides, fungicides, [2] and other pesticides. Pesticides are chemicals that play an important role in increasing crop yield and mitigating crop losses. [3] These work to keep insects and other animals away from crops to allow them to grow undisturbed, effectively regulating pests and diseases.
Disadvantages of pesticides include contamination of the ground and water (see persistent organic pollutants). They may be toxic to non-target species, including birds, fish, [4] pollinators, [5] as well as the farmworkers themselves.
Agricultural chemistry often aims at preserving or increasing the fertility of soil with the goals of maintaining or improving the agricultural yield and improving the quality of the crop. Soils are analyzed with attention to the inorganic matter (minerals), which comprise most of the mass of dry soil, and organic matter, which consists of living organisms, their degradation products, humic acids and fulvic acids. [8]
Fertilizers are a major consideration. While organic fertilizers are time-honored, their use has largely been displaced by chemicals produced from mining (phosphate rock) and the Haber-Bosch process. The use of these materials dramatically increased the rate at which crops are produced, which is able to support the growing human population. Common fertilizers include urea, ammonium sulphate, diammonium phosphate, and calcium ammonium phosphate. [9] [10]
Agricultural chemistry encompases the science and technology of producing not only edible crops, but feedstocks for fuels ("biofuels") and materials. Ethanol fuel obtained by fermentation of sugars. Biodiesel is derived from fats, both animal- and plant-derived. Methane can be recovered from manure and other ag wastes by microbial action. [11] [12] Lignocellulose is a promising precursor to new materials. [13]
Biocatalysis is used to produce a number of food products. More than five biilion tons of high fructose corn syrup are produced annually by the action of the immobilized enzyme glucose isomerase of corn-derived glucose. Emerging technologies are numerous, including enzymes for clarifying or debittering of fruit juices. [14]
A variety of potentially useful chemicals are obtained by engineered plants. Bioremediation is a green route to biodegradation.
Genetically Modified Organisms (GMO's) are plants or living things that have been altered at a genomic level by scientists to improve the organisms characteristics. These characteristics include providing new vaccines for humans, increasing nutrients supplies, and creating unique plastics. [15] They may also be able to grow in climates that are typically not suitable for the original organism to grow in. [15] Examples of GMO's include virus resistant tobacco and squash, delayed ripening tomatoes, and herbicide resistant soybeans. [15]
GMO's came with an increased interest in using biotechnology to produce fertilizer and pesticides. Due to an increased market interest in biotechnology in the 1970s, there was more technology and infrastructure developed, a decreased cost, and an advance in research. Since the early 1980s, genetically-modified crops have been incorporated. Increased biotechnological work calls for the union of biology and chemistry to produce improved crops, a main reason behind this being the increasing amount of food needed to feed a growing population. [16]
That being said, concerns with GMO's include potential antibiotic resistance from eating a GMO. [15] There are also concerns about the long term effects on the human body since many GMO's were recently developed. [15]
Much controversy surrounds GMO's. In the United States, all foods containing GMO's must be labeled as such. [17]
Particularly relevant is proteomics as protein (nutrition) guides much of agriculture.
Fungicides are pesticides used to kill parasitic fungi or their spores. Fungi can cause serious damage in agriculture, resulting in critical losses of yield, quality, and profit. Fungicides are used both in agriculture and to fight fungal infections in animals. Fungicides are also used to control oomycetes, which are not taxonomically/genetically fungi, although sharing similar methods of infecting plants. Fungicides can either be contact, translaminar or systemic. Contact fungicides are not taken up into the plant tissue and protect only the plant where the spray is deposited. Translaminar fungicides redistribute the fungicide from the upper, sprayed leaf surface to the lower, unsprayed surface. Systemic fungicides are taken up and redistributed through the xylem vessels. Few fungicides move to all parts of a plant. Some are locally systemic, and some move upward. Most fungicides that can be bought retail are sold in liquid form, the active ingredient being present at 0.08% in weaker concentrates, and as high as 0.5% for more potent fungicides. Fungicides in powdered form are usually around 90% sulfur.
Carbendazim is a fungicide, a member benzimidazole fungicides. It is a metabolite of benomyl.
Ammonium iodide is the inorganic compound with the formula NH4I. A white solid. It is an ionic compound, although impure samples appear yellow. This salt consists of ammonium cation and an iodide anion. It can be prepared by the action of hydroiodic acid on ammonia. It is easily soluble in water, from which it crystallizes in cubes. It is also soluble in ethanol. Ammonium iodide in aqueous solutions are observed as acidic and display elevated vapor pressures at high temperatures
p-Cymene is a naturally occurring aromatic organic compound. It is classified as an alkylbenzene related to monocyclic monoterpenes. Its structure consists of a benzene ring para-substituted with a methyl group and an isopropyl group. p-Cymene is insoluble in water, but miscible with organic solvents.
Camphene is a bicyclic organic compound. It is one of the most pervasive monoterpenes. As with other terpenes, it is insoluble in water, flammable, colorless, and has a pungent smell. It is a minor constituent of many essential oils such as turpentine, cypress oil, camphor oil, citronella oil, neroli, ginger oil, valerian, and mango. It is produced industrially by isomerization of the more common alpha-pinene using a solid acid catalyst such as titanium dioxide.
Rhenium(VII) oxide is the inorganic compound with the formula Re2O7. This yellowish solid is the anhydride of HOReO3. Perrhenic acid, Re2O7·2H2O, is closely related to Re2O7. Re2O7 is the raw material for all rhenium compounds, being the volatile fraction obtained upon roasting the host ore.
Dodecylbenzene is an organic compound with the formula C
12H
25C
6H
5. Dodecylbenzene is a colorless liquid with a weak oily odor that floats on water.
Linalyl acetate is an organic compound, the acetate ester of linalool and a phytochemical found in many flowers and spice plants. It is one of the principal components of the essential oils of bergamot and lavender. It often occurs together with linalool and is a widely used fragrance.
tert-Butyl hydroperoxide (tBuOOH) is the organic compound with the formula (CH3)3COOH. It is one of the most widely used hydroperoxides in a variety of oxidation processes, like the Halcon process. It is normally supplied as a 69–70% aqueous solution. Compared to hydrogen peroxide and organic peracids, tert-butyl hydroperoxide is less reactive and more soluble in organic solvents. Overall, it is renowned for the convenient handling properties of its solutions. Its solutions in organic solvents are highly stable.
Perfluorotripentylamine is an organic compound with the chemical formula N( 4CF3)3. A molecule of this chemical compound consists of three pentyl groups connected to one nitrogen atom, in which all of the hydrogen atoms are replaced with fluorine atoms. It is a perfluorocarbon. It is used as an electronics coolant, and has a high boiling point. It is colorless, odorless, and insoluble in water. Unlike ordinary amines, perfluoroamines are of low basicity. Perfluorinated amines are components of fluorofluids, used as immersive coolants for supercomputers.
4-Hydroxybenzaldehyde (2-hydroxybenzaldehyde) is an organic compound with the formula C6H4OH(CHO). Along with 2-hydroxybenzaldehyde and 3-hydroxybenzaldehyde, it is one of the three isomers of hydroxybenzaldehyde.
Extraction in chemistry is a separation process consisting of the separation of a substance from a matrix. The distribution of a solute between two phases is an equilibrium condition described by partition theory. This is based on exactly how the analyte moves from the initial solvent into the extracting solvent. The term washing may also be used to refer to an extraction in which impurities are extracted from the solvent containing the desired compound.
Propylbarbital, also known as 5,5-dipropylbarbituric acid, is a barbiturate derivative used as a hypnotic drug.
Acetoacetanilide is an organic compound with the formula CH3C(O)CH2C(O)NHC6H5. It is the acetoacetamide derivative of aniline. It is a white solid that is poorly soluble in water. This chemical and many related compounds (prepared from various aniline derivatives) are used in the production of organic pigments called arylide yellows. Acetoacetanilides usually exist as the keto-amide tautomer according to X-ray crystallography.
Salicyl alcohol (saligenin) is an organic compound with the formula C6HOH(CH2OH. It is a white solid that is used as a precursor in organic synthesis.
o-Cymene is an organic compound classified as an aromatic hydrocarbon. Its structure consists of a benzene ring ortho-substituted with a methyl group and an isopropyl group. It is a flammable colorless liquid which is nearly insoluble in water but soluble in organic solvents.
m-Cymene is an organic compound classified as an aromatic hydrocarbon. Its structure consists of a benzene ring meta-substituted with a methyl group and an isopropyl group. It is a flammable colorless liquid which is nearly insoluble in water but soluble in organic solvents.
Geranylacetone is an organic compound with the formula CH3C(O)(CH2)2CH=C(CH3)(CH2)2CH=C(CH3)2. A colorless oil, it is the product of coupling geranyl and acetonyl groups. It is a precursor to synthetic squalene.
Benzimidazolinone is an organic compound with the formula C6H4(NH)2CO. Also classified as a heterocyclic compound it is a bicyclic urea. It is a tautomer of 2-hydroxybenzimidazole.
Toluidine red is an organic compound with the formula C10H6(OH)(N2C6H3 CH3). A dark red solid, the compound is classified as a azo dye consisting of a 2-naphthol group linked to a 2-nitro-4-methylphenyl substituent. Toluidine red is a traditional pigment, found in oil paints. Although once popular, it suffers as a pigment owing to "insufficient lightfastness and bleeding when incorporated into a paint system."
