Showing posts with label farming. Show all posts
Showing posts with label farming. Show all posts

Sunday, November 7, 2010

Energy Budget of Food Production

Farming's Energy Budget

When farming and producing food, one needs to examine the inputs, outputs, flows and storages in order to determine the energy budget.
e.g. fuels, chemicals, labor, materials, transports, wastes, energetic content of products.

Also consider that the marketable product which is produced is only a % of the total output, which may not be marketable.

For every watt of input I get ___ watts of product (dairying, cereals, etc.)

Comparing Aquatic vs. Terrestrial Food Production

Terrestrial:
  • Food harvested from 1st or 2nd trophic levels thus more energetically efficient.
  • Solar energy capture (GPP) more efficient.
  • Energy transfers between trophic levels not as efficient.
Aquatic:
  • Most food is harvested from higher trophic levels, thus not as efficient
  • Solar capture (GPP) not as efficient due to absorption of sunlight by water
  • Energy transfers between trophic levels fairly efficient.

Farming and Food Production

Types of Farming Systems
1. Subsistence: provision of food for family and their community; little or no surplus; mixed crops; extensive use of human labor; low use of fossil fuels, chemicals, and capital; little technology.
2. Commercial: large profit generating scale; maximized yields, monocultures; high levels of technology, energy, and chemical inputs.

Farming can also be described as:

1. Extensive: uses more land with a lower density of animals or crops; lower inputs and outputs.
2. Intensive: intensive use of land; high inputs and outputs

And as:
i. Pastoral
ii. Arable
iii. Mixed