Applied chemistry of food production: fertilizers, pesticides, soil amendments, plant protection chemicals. Substrate of industrial agriculture.
agrochemistry
Haber–Bosch ammonia synthesis
N₂ + 3 H₂ ⇌ 2 NH₃ over Fe (or Ru) catalyst at ~450°C/200 atm. Produces ~200 Mt NH₃/y globally; feeds ~50% of human population via…
NPK fertilizer
Macro-nutrient formulation (N-P₂O₅-K₂O w/w%, e.g. 10-10-10). N as urea/NH₄NO₃, P as superphosphate (Ca(H₂PO₄)₂) or DAP, K as KCl/K₂SO₄.…
Soil fertility management
Balance of macro-nutrients (N, P, K), secondary (Ca, Mg, S), and micronutrients (Fe, Mn, Zn, Cu, B, Mo, Cl) plus pH, CEC, and organic…
Pesticide classification
By target (herbicide, insecticide, fungicide, rodenticide, nematicide) and mode of action (HRAC/IRAC/FRAC codes). Resistance management…
Glyphosate
N-(phosphonomethyl)glycine; non-selective systemic herbicide inhibiting shikimate-pathway enzyme EPSPS (only in plants and microbes, not…
Neonicotinoids
Nicotinic-acetylcholine-receptor (nAChR) agonists (imidacloprid, thiamethoxam, clothianidin) with high insect/mammal selectivity. Extremely…
Biopesticide
Pest-control agents derived from natural materials: Bt Cry toxins (Lepidoptera-specific), Beauveria bassiana (fungal), RNAi dsRNA,…
Controlled-release fertilizer
Polymer-coated urea or sulfur-coated pellets release N over weeks via diffusion/hydrolysis, reducing leaching losses (typically from 40% to…
Precision agriculture (GPS + remote sensing)
Variable-rate-application of fertiliser / water / pesticide via GPS-guided machinery + satellite-multispectral imagery (NDVI vegetation…
Integrated pest management (IPM)
Stern-van-den-Bosch 1959 IPM: economic-injury-level threshold defines pest population above which intervention beneficial. Multi-tactic…
Fertiliser runoff & eutrophication
Excess N-P fertiliser runs off into rivers / coastal-waters → algal-blooms → hypoxic dead-zones (Gulf of Mexico, Baltic). …
Soil organic carbon sequestration
Lal 2004: agricultural soils can sequester ~1-3 Gt CO₂eq/yr via no-till, cover-cropping, agroforestry, biochar amendment. 4-per-1000…
Haber-Bosch process (1913)
Haber-Bosch 1913 N2 + 3H2 -> 2 NH3 at 200 atm + 450 C over Fe-K2O catalyst; Nobel 1918+1931; sustains ~50% of human population via…
Phosphate fertilizer (superphosphate)
Lawes-Gilbert 1843 superphosphate: Ca3(PO4)2 + 2 H2SO4 -> Ca(H2PO4)2 + 2 CaSO4; water-soluble P; phosphate-rock reserves (Morocco, China)…
Glyphosate (shikimate inhibitor)
Franz-Monsanto 1970 glyphosate: inhibits EPSP-synthase in shikimate pathway (absent in animals); broad-spectrum; Roundup-Ready 1996…
Pyrethroid (Na+ channel modulator)
Permethrin/cypermethrin 1970s: synthetic pyrethrins target voltage-gated Na+ channels in insect axons; knockdown effect; lower mammalian…
Integrated Pest Management (IPM)
Stern-Smith-Bosch 1959 IPM: economic-injury-level threshold + biological-control + crop-rotation + selective pesticide use; reduces…
Soil cation exchange capacity (CEC)
Way 1850 / Thompson 1850 CEC: clay + organic-matter negative-sites bind K+, Ca2+, Mg2+, NH4+; CEC meq/100g soil predicts nutrient retention…
Silent Spring (Carson 1962)
R Carson 1962 'Silent Spring' DDT toxicity; modern Stockholm-Convention + bird-population recovery + persistent-organic-pollutants.
Green revolution (Borlaug 1966)
N Borlaug 1966 (Nobel-Peace 1970) semi-dwarf-wheat + nitrogen-fertilization; modern doubling agricultural productivity.
Rotenone toxicity (Shimkin 1939)
M Shimkin 1939 rotenone complex-I-NADH-dehydrogenase; modern Parkinson's-mitochondrial-link + GMO Bt-toxin.
Bt-toxin (Schnepf 1981)
Schnepf-Whiteley 1981 cry-protein cloning; modern GM-corn + GM-cotton + 100M+ ha global Bt-crop deployment.
Rhizobium (Beijerinck 1888)
M Beijerinck 1888 root-nodule N2-fixation; modern legume-microbe symbiosis + nif-gene cluster + Sym plasmid.
Phytochrome (Borthwick 1952)
Borthwick-Hendricks 1952 phytochrome red/far-red; modern molecular clock + flowering-time-gene control + crop-engineering.