Soil Flashcards
what is soil made of?
minerals, organic matter, air and water
why is soil important?
soil ehances : plant growth, stores 0.005% of the worlds freshwater, is the habitat of millions of micro-organisms
soil horizons :
o - organic matter
a - surface soil
b - subsoil
c - parent rock
r - bed rock
types of farming :
subsistence, commericial
subsistence farming :
for their own food - of the farmers
INPUTS : low use of technology, fertilizers
OUTPUTS : low yields, high soil losses
commercial farming :
INPUTS : fertilizers, pesticides, high use of technology
OUTPUTS : pollution runoff, animal waste, soil losses
what is soil degredation?
the biological and chemical decline in soil quality
main cause of soil degredation?
human activity - agriculture for example
agricultural case studies :
monoculture - IOWA Corn
polyculture - Cuba
IOWA corn
pesticides, carbon & toxic emmisions - going into lakes due to lack of infiltration
increasing pollution and co2 emmissions
Cuba polyculture
reduces pollution, pests, saves money, low use of pesticides
PH - if its low is it acid or not?
acid - the lower the PH level (0-7) the more acidic it is
define Sustainable Yield
the amount of a natural resource that can be taken from an ecosystem without reducing the base stock.
suggest one possible sollution that a technocentrist might give to the problem of overfishing
ex. another way of fish farming - for less waste
tractors overpowering farm labour means…
agriculture is being mechanized, more technology is required (especially if farming becomes larger)
‘tips’ for increasing agricultural production in less economically developed countries :
more use of pesticides to protect crops and livestock - better export
soil management techniques : agroforestry
define soil erosion
gradual process that occurs when the impact of water or wind detaches and removes soil particles - causing the soil to deteriorate - which have become severe problems worldwide.
define toxicfication
when toxic chemicals are present in soil (ex. pollutants) and they are in high concentrations - therefore putting humans health at risk
define desertification
when a land looses its wildlife, bodies of water and vegetation, due to such drought / land degredation
outline the transfers, transformations, inputs, outputs, flows and storages within soil systems :
inputs : minerals, organic matter, water
outputs : erosion, leaching, uptake by plants
transfers : transcolation, leaching
transformation : decomposition, nutrient cycling
storages : minerals, organic matter, organisms
how soil can be viewed as an ecosystem?
billions of organisms inhabit the upper layers of the soil, where they break down dead organic matter, releasing the nutrients necessary for plant growth.
soil structure depends on…
earthworms activity, amount of sand and clay, dead organic matter
different soil types have different levels of primary productivity:
sandy soil – low
clay soil – quite low
loam soil – high
terrestial food production systems is influenced by…
socio-political, ecological and economic factors
distinguish between the reasons for food waste in less economically developed countries and more economically developed countries
as countries develop, more food is put to waste and more pollution there is
MEDCs have higher levels of consumption, so they produce more waste than LEDCs
- as a country becomes more wealthy, the demand for consumer items increases. This means that items are replaced more frequently - leading to larger quantities of waste.
in LEDCs waste production is lower because:
less is bought because people are typically on lower incomes
less packaging is used on products
lower literacy levels means there is less production of written material
explain how human population growth will affect food production systems and sustainability.
as the human population grows, along with urbanization and degradation of soil resources, the availability of land for food production per capita decreases.
how has increase of science and technology in agriculture helped?
advances in agricultural science and technology have contributed to remarkable increases in food production since the mid-twentieth century. Global agriculture has grown 2.5–3 times over the last 50 years.
organic farming :
provides an ecocentric approach
balance that conserves soil fertility, reduces pest outbreaks and takes a preventative rather than reactive approach
creates local markets
reduces food miles
polyculture instead of monoculture
growing multiple crops instead of one - less pesticides used as well
legislation
ex. controlling pesticides
evaluate strategies to increase sustainability in terrestrial food production systems.
- change in social and individual behavior.
- local produce and use of farmers markets
- food Labels
- use of polyculture instead of monoculture farming involves growing multiple crops rather than focusing only on one.
- reduction of meat production. The ecological footprint of meat production is significantly greater than for crop production
overcropping
this constant farming of the land reduces the soils ability to produce valuable humus for soil fertility as it is constantly being plowed or stripped for crop growth. The soil becomes drier and less fertile.
leaching
percipitation -> water moves downwards
tilling
prepare and cultivate (land) for crops
intensive farming
have more inputs and outputs
extensive farming
uses more land with lower density of stocking or planting
arable farming
growing crops on good soil to eat or feed directly to animals
mixed farming
has both animals and grows crops
pastoral farming
raising animals on land that is not suitable for crops
