notes Agricultural Energetics (by Richard C. Fluck and C. Direlle Baird)

 Agriculture industry geting energy from the sun and produce caloric energy.

Energy cannot be created or destroyed - only converted.

Conversion of electical energy to mechanical - usually has most efficiency.
Fluorescent lamps have more efficiency than incandescent lamps. *but LED win!now

Food is not only sun energy, but also oil, gas, coil - because of energy while development(and growing) agro system.

Natural ecosystems run on solar energy. Incoming solar energy - solar constant 1.395 * 10^-3 MJ m^-2*s^-1
After calc without darkness, clouds - beetween 0.09 to 0.29
30% - directly reflected, 47% - converted to heat - only 0.02% for photosyntesis.

Energy from plants -> Animal muscle energy.
Man need - ~10.46 MJ. Possible to calc from where and how much energy man is getting.

The Agriculture society next from the hunting society.
Old agro societies - energy from the sun, labor people and animals.
In industrial societies - sun and mostly oil energy.
*Energy efficiency of society, Energy flows
**When calc - start from energy input(or sun) and then downstairs to the human energy
***Food chains - input of materials & energy, to the system(production, processing, packing, transportation, marketing), to the retail food
**** increasing energy for processing in the system - reducing energy for consumer
***** energy: packing/processing > production, transportation+marketing = 50% of full energy
***** just interesting note: when you go to restaurant you burn 800MJ in gasoline to consume 8MJ meal

Energy analysis - discipline. With schools:
1) Odum school
2) IFIAS school (International Federation of Institutes for Advanced Study)
identification, measurement and analysis of energy flows

Energy ratio - if not enough energy produced = hungry.
Energy output /  Energy expended
* for long-term societies 15/1
limitations: when workers independent, when food not only energy

Energy Productivity
How much product obtained per unit of input
for example: land productivity, labour productivity

Net Energy Analysis
1)External input
2)Energy processing system - Y
3)Economy, feedback loop (3->2) - F
* how much energy stays in consumer after producing Y minus F

Inputs of Agricultural:
*each input need energy
Plant nutrients - inputs of nitrogen, phosphorus, potash, etc.
Pesticides - herbicides, insecticides, fungicides, rodenticides.
Machinery and fuel - including maintenance and repairs.
Irrigation - pumping and distribution systems.
Labor - muscular energy, consumed food, lifestyle energy.
Land - collect and utilize solar energy, chemicals in soil/water.
Containers and transportation.
Draft animals - work accomplished/energy expended.
Environmental control - heating/cooling, refrigeration, lighting.
Processing - crop drying, conveyors, elevators.
**all inputs can be different types - different energy requirments.
**possible to convert to fossil fuel equivalents

Economics in energy:
energy cost in terms of money depend from supply, form of energy, quality, pollution, goverment regulations, location, transport, technology
*cost of energy will continue to grow, until of new energy sources
**it occur shifting of the products - some products will be luxury, less energy-intensive 'll be more predominant
***one of suggested lines of future - shift of production and consumption from livestock to grain products(vegy and fruits(outdoor) 'll still the same because no need much processing) - this is the look from 1976, good as example of the agriculture's transforming by changing of energy economics

Alternatives:
Less production and/or population control
*Population will be limited - if not by birth control but by starvation, warfare and disease
Intermediate technology
*Appropriate technology - some agriculture might be de-industrialised(low-energy agriculture, Amish-type farming)
Increased energy productivity
*improving Inputs/Outputs, reduction of losses(pests and parasites, pathogen), use of fertilizers+pesticides+mechanization, scientific advances, multiple cropping, timing