Lecture 8: Nutrient crisis in agriculture Flashcards
What is soil fertility?
Concentration of nutrients required for successful growth
What is the limiting factor of soil fertility?
Plant nutrients need to be in a biologically active form accessible to plants
Which nutrient requires mobilisation in soils?
Nitrogen required weathering or recycling via microbes to become active
What is farming?
mining the soil of nutrients so we can eat them
Which systems benefit nutrient recycling?
Manure
Compost
Crop residues
Intercropping
Rotation
Weathering (slash and burn)
What is weathering (slash and burn)?
burn landscape to introduce phosphorous into soils through biologically-active forms in ash
What is the connection between traditional farming systems?
Connection between farming and society as need nutrient return
Issues with traditional connected agriculture
prone to famine and over use
at threat if localised
climatic/social events cause food insecurity
What happened in the 1800s?
global shipping networks of guarno reserves led to wars over resource allocation
What happened in the 1900s?
discovered Haber-Bosch process to convert innaccessible nitrogen gas to ammonia
What happened in 1940s?
Uptick in mining rock phosphate
What happened in 1960s?
Green revolution
What is green revolution?
Plant breeding programmes for productivity and higher nutrient inputs
Issues with industrial nutrient cycling
Leaky system
Runoff
GHG emissions
Delocalised nutrient flows restructure society
How is industrial nutrient cycling extractive?
Only a few countries produce finite resources
Extraction is occurring at millions of years rate not in line with seasonal use before
Positive impacts of industrial farming
Freely expand populations as less famine
Reduced hunger, increased population, maintain land use
Increased productivity
Costs of industrial farming
Limited supplies of nutrients
Over application issues
Crop breeding reduced reliance on microbes
Crop breeding has reduced microbe ability to form beneficial symbioses
How can we tackle the nutrient crisis?
Tailor solutions to local environments
Prioritise soil health
More diverse, nutrient enhancing crops
Use microbial tools
