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Social sciences:

Geography

Grade 8

Natural resources

Module 8

Agriculture, forrestry and alien invaders

Agriculture

The greatest damage that humans inflict on the earth – and by implication, the greatest threat that humanity poses to its own future survival – is through the practice of agriculture. Huge areas of the planet’s natural terrestrial ecosystems have already been destroyed and replaced with artificial agricultural systems, greatly reducing or even negating the ability of the land to control and influence its own climate and chemistry.

Of South Africa’s surface area of some 120 million hectares, about 85 per cent is used for agriculture and forestry. Only 45 per cent of the country receives more than 500 mm rain annually – the generally accepted minimum for dryland crop production – and only 12 per cent is suitable for cultivation. The rest is mainly natural veld used for grazing.

Because of the lack of suitable planning in the past and gross over subsidisation – often to win political favour – much prime arable land has been irrevocably lost to urbanisation, mining (particularly on the Witwatersrand and in Mpumalanga) and other activities. Also, injudicious management and cultivation of crops not ecologically suited to conditions have caused widespread degradation in the form of soil erosion and desertification. Annual soil losses, mostly through poor land husbandry practices, are estimated at between 300 and 400 million tonnes annually.

The question of existing land ownership in agriculture is being addressed as a matter of urgency by the Government of National Unity. Before the 1994 elections, an estimated 50 000 white farmers – many of them heavily subsidised for political reasons and extensively in debt to an amount of R14 billion – owned some 85 million hectares, of which about 14,3 million were arable. The 700 000 black farmers in the former “homeland” areas had access to only some 15 million hectares, of which only 2,3 million were arable.

Activity 1:

To identify the poor management of agricultural land and suggest precautionary measures

[lo 3.3]

1. Underline the correct words. Explain your choice.

  • Livestock must be decreased/increased to remain within the capacity of the land.
  • The simultaneous cultivation of crops and the keeping of livestock must be encouraged/discouraged .

2. Why is it necessary that the use of fertilizers, insecticides and weed killers should be strictly controlled? Give your opinion.

3. In what respect does urbanisation contribute to the destruction of agricultural land?

Forestry

Forests are an integral part of Earth’s life-support systems, playing a crucial role in regulating the atmosphere and climate through their ability to store carbon and drive local hydrological cycles. They protect soils from excessive erosion, regulate run-off and reduce the effect of floods and consequently silt loads in rivers. Natural forests are usually highly diverse ecosystems, supporting millions of species and providing human beings with a wealth of benefits. They are also an important part of the resource base for tourism and recreation, and have an inestimable cultural value as a source of beauty, contemplation and inspiration that finds expression in art, music, literature, dance and religion.

Questions & Answers

who was the first nanotechnologist
Lizzy Reply
k
Veysel
technologist's thinker father is Richard Feynman but the literature first user scientist Nario Tagunichi.
Veysel
Norio Taniguchi
puvananathan
Interesting
Andr
I need help
Richard
anyone have book of Abdel Salam Hamdy Makhlouf book in pdf Fundamentals of Nanoparticles: Classifications, Synthesis
Naeem Reply
what happen with The nano material on The deep space.?
pedro Reply
It could change the whole space science.
puvananathan
the characteristics of nano materials can be studied by solving which equation?
sibaram Reply
plz answer fast
sibaram
synthesis of nano materials by chemical reaction taking place in aqueous solvents under high temperature and pressure is call?
sibaram
hydrothermal synthesis
ISHFAQ
how can chip be made from sand
Eke Reply
is this allso about nanoscale material
Almas
are nano particles real
Missy Reply
yeah
Joseph
Hello, if I study Physics teacher in bachelor, can I study Nanotechnology in master?
Lale Reply
no can't
Lohitha
where is the latest information on a no technology how can I find it
William
currently
William
where we get a research paper on Nano chemistry....?
Maira Reply
nanopartical of organic/inorganic / physical chemistry , pdf / thesis / review
Ali
what are the products of Nano chemistry?
Maira Reply
There are lots of products of nano chemistry... Like nano coatings.....carbon fiber.. And lots of others..
learn
Even nanotechnology is pretty much all about chemistry... Its the chemistry on quantum or atomic level
learn
Google
da
no nanotechnology is also a part of physics and maths it requires angle formulas and some pressure regarding concepts
Bhagvanji
hey
Giriraj
Preparation and Applications of Nanomaterial for Drug Delivery
Hafiz Reply
revolt
da
Application of nanotechnology in medicine
has a lot of application modern world
Kamaluddeen
yes
narayan
what is variations in raman spectra for nanomaterials
Jyoti Reply
ya I also want to know the raman spectra
Bhagvanji
I only see partial conversation and what's the question here!
Crow Reply
what about nanotechnology for water purification
RAW Reply
please someone correct me if I'm wrong but I think one can use nanoparticles, specially silver nanoparticles for water treatment.
Damian
yes that's correct
Professor
I think
Professor
Nasa has use it in the 60's, copper as water purification in the moon travel.
Alexandre
nanocopper obvius
Alexandre
what is the stm
Brian Reply
is there industrial application of fullrenes. What is the method to prepare fullrene on large scale.?
Rafiq
industrial application...? mmm I think on the medical side as drug carrier, but you should go deeper on your research, I may be wrong
Damian
STM - Scanning Tunneling Microscope.
puvananathan
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Source:  OpenStax, Geography grade 8. OpenStax CNX. Sep 11, 2009 Download for free at http://cnx.org/content/col11036/1.1
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