Types of Agriculture Local Issues, Global Trends

Subsistence Agriculture  Product of land is consumed locally  Only enough food grown to survive  Two types  Sedentary (in one place)  Shifting cultivation  Often damaging to environment  Slash and burn

Cash Crops  Product of farms largely sold for export out of region  Family farm  Plantation system  Agribusiness  Can result in a monoculture  One type of plant predominating  Challenge to biodiversity

Think About  How do we figure out what the best agricultural land use is given competing crops?  In particular, how close or far from a market center do we need to be?

Agricultural Land Use Von Thünen’s Model

What’s the Issue?  Geographers are concerned with space and distance  How are various agricultural crops distributed across space?

Johann Heinrich von Thünen   German  The Isolated State (1826)  Spatial Economics  Economic Rent  What one would be willing to pay to be in a particular location

Assumptions  A featureless (isotropic) plain  Central city in isolation  Farmers transport goods to market by oxcart over land  there are no roads  Location will be a function of crop value, costs of production and distance to market

Bid Rent  R = Y(p-c) – YFm  R = bid rent  Y = crop yield  p = price of crop  c = costs of production  F = Freight costs  m = mileage to market

Examples: Plot the Lines R=Y(p-c)-YFm  Per Y = 1, m =  Peppers  p = $20  c = $10  F = $2  Wheat  p = $16  c = $8  F = $1

Bid Rent Curves

Land Use Zones