6. Agriculture

• Agriculture


  The science, art, or practice of cultivating the soil, producing crops, and raising livestock
• Agriculture


  • One of the largest and most significant industries in the world
• Biofertilizers


  Living microbes that enhance plant nutrition
• Nobbe and Hilther introduced biofertilizers


  1895
• Types of biofertilizers

  • Bacteria
  • Algae
  • Fungi
• Biofertilizers


  • Low-cost renewable sources of plant nutrients
• Biocontrol agents


  Organisms or microorganisms that control plant pathogens
• Charles Valentine Riley introduced biocontrol agents


  Late 1800s
• Biocontrol agents

  • Must be very host specific in order to be released
  • Predators, parasitoids, and pathogens
  • Trichoderma (fungus) and Baculoviruses
• Types of biofertilizers

  • Free-living nitrogen-fixing bacteria (e.g. Azotobacter, Rhodospirillum)
  • Free-living nitrogen-fixing Cyanobacteria (e.g. Anabaena, Nostoc)
  • Loose association of nitrogen-fixing bacteria (e.g. Azospirillum)
  • Symbiotic nitrogen-fixing bacteria (e.g. Rhizobium, Frankia)
• Benefits of biofertilizers

  • Eco-friendly and not harmful to the environment
  • Improve soil quality and increase plant productivity
  • Farmers can prepare inoculum and inject into plants
  • Produce growth-promoting substances in soil
• Biofertilizers used in organic farming

  • Rhizobium
  • Azospirillum
  • Azotobacter
  • Cyanobacteria or Blue-Green Algae
  • Phosphate Solubilizing Bacteria
  • Mycorrhizal fungi
  • Frankia
• Microbial biocontrol agents


  Used to control the growth of other microorganisms, pests, and pathogens
• Benefits of microbial biocontrol agents

  • Eco-friendly, sparing beneficial organisms and the environment
  • Control various pests and diseases: insects, mites, weeds, fungi, bacteria
  • Kill pests by infecting, competing, or producing toxins
  • Offer specific, effective, long-term, self-sustaining pest control
• Antibiotics


  A class of drug used to treat bacterial infections by either killing bacteria or inhibiting their growth
• Uses of antibiotics in agriculture

  • Livestock used to treat and prevent diseases and promote growth
  • Crop used to control bacterial diseases
• Antibiotic resistance


  The phenomenon where bacteria evolve mechanisms to survive exposure to antibiotics, the drugs designed to kill them or stop their growth
• How antibiotics are introduced into soil

  • Animals (manure)
  • Plant treatments
• Mechanisms of how soil microorganisms become antibiotic resistant

  • Mutation
  • Selective pressure
  • Acquisition of new genetic material
• Impact of antibiotic resistance on soil microorganisms

  • Change the microbial communities
  • Resistant bacteria proliferation
• The adoption of biofertilizers and biocontrol agents has transformed agriculture by enhancing soil fertility, promoting eco-friendly practices, and providing targeted pest control
• The rise of antibiotic resistance in soil microorganisms underscores the need for responsible antibiotic use in farming
• Integrating these technologies into agricultural systems represents a crucial step towards sustainable food production and environmental protection