Extension: a Bridge between Science and Daily Life



Increased human population is driving changes in crop and animal production methods 

In the past, farms are small and diversified. A closed nutrient cycle is well maintained. Now, farms become larger and specialized. Many farms are net purchasers of feed and exporters of manure to crop farms. Manure production and manure utilization have become uncoupled. Nutrients and waste become concentrated in certain regions and the nutrient cycle becomes disconnected and difficult to manage. Disrupted or mismanaged nutrient cycle results in various environment problems. Emission can happen in various link of the nutrient cycle.

The “Good old days"

Modern Systems

  • Family farm system
  • Small operations
  • Resources were cycled: a closed loop for most nutrients
  • Low productivity
  • Farms grew larger
  • Became specialized
  • Productivity increased
  • Nutrients concentrated in certain regions
  • Disconnected nutrient cycle




  • Food safety
  • Animal rights and welfare movement
  • Water availability
  • Environmental concerns
  • Climate change


  • Well-educated specialists
  • Improvement of information technology, with access in rural areas
  • Ability of producers to access information