Agriculture

Grade 7 & 8
Term 1 Module

Name:
_________________________
 Different Forms of Land Use
Topic 1

What is Agriculture?
Agriculture is the art and science in cultivating the soil, growing crops and
raising livestock. It includes the preparation of plant and animal products for
people to use and their distribution to markets. Agriculture provides most of
the world’s food and fabrics. Agriculture also provides fibre (produced from
fibre crops) and leather for clothes, wood for construction and paper products.
Cotton, wool, and leather are all agricultural products. These products, as well
as the agricultural methods used, may vary from one part of the world to
another based on the resources available.

The agricultural industry provides for the essential human requirements, it is the
primary industry in any country of the world, and it supplies the real needs of people
as a:

 Provider of Food Man cannot produce food himself and is therefore directly
dependent on agriculture for his food. Therefore, agriculture is one of the most
important industries on earth. In Southern Africa more than enough food is produced
for its own use, as well as considerable quantities for export purposes.

 Provider of Raw Materials The largest percentage of a country's agricultural soil

is used for food production, but an important and ever-growing percentage is used to
produce agricultural products which, although of limited food value, are also used in
manufacturing processes. Agricultural products are also used to supply industries
with raw materials as follows:

- Fibres: cotton, sisal, flax, wool, mohair.

- Commercial products: tobacco, alcoholic drinks (grapes and grains), castor oil,
tea and coffee, glue (maize), dairy products, oil (oil seeds), leather (hides and skins).
- Products for the canning industry: meat, vegetables and fruit.

 Provider of Work Opportunities More than 50% of the total population of

Southern Africa live from or are directly dependent on agriculture for their livelihoods.
This varies from owners, farm managers, farm foremen, workers and their families,
to those who process and sell agricultural products.
 Provider of Economic Stability Although agriculture has only been market-
oriented since the 1950's, it succeeded in its two basic aims, namely, to produce
enough basic products for the population of Southern Africa and to earn foreign
exchange.

Main Forms of Land Use: Key Terms

Pathogens: any organism

or agent that can produce
disease
1. Monoculture Green Manure: a crop
2. Crop Rotation specifically produced to be
3. Mixed incorporated into the soil
while still green.
4. Forestry
Polyculture: the practice of
5. Aquaculture growing more than one
crop species in the same
space, at the same time.

1.Monoculture:
In agriculture, monoculture is the practice of growing one crop species in a field at a
time. Monoculture is widely used in intensive farming and in organic farming.

2.Crop Rotation:
Crop rotation is the practice of growing a series of dissimilar types of crops in the
same space in sequential seasons to avoid the build up of pathogens and pests that
often occurs when one species is continuously cropped. Crop rotation also seeks to
balance the fertility demands of various crops to avoid excessive depletion of soil
nutrients. A traditional component of crop rotation is the replenishment of nitrogen
through the use of green manure in sequence with cereals and other crops. It is one
component of polyculture. Crop rotation can also improve soil structure and fertility
by alternating deep-rooted and shallow-rooted plants.

Method and Purpose of Crop Rotation:

Crop rotation avoids a decrease in soil fertility, as
growing the same crop repeatedly in the same Key Terms
place eventually depletes the soil of various
nutrients. A crop that leaches the soil of one kind Fabaceae: commonly
of nutrient is followed during the next growing known as the legume, pea, or
season by a dissimilar crop that returns that bean family.
nutrient to the soil or draws a different ratio of Poaceae: plants commonly
known as grasses. Includes
nutrients, for example, rices followed by cottons. the cereal grasses, bamboos
By crop rotation, farmers can keep their fields and reeds.
under continuous production without the need to Nirates: chemical compound
let them lie unpropductive, and reducing the need that includes nitrogen and
for artificial fertilizers, both of which can be oxygen. Nitrates are used as
expensive. fertilizers in agriculture.
Taxonomic Family:
Ergot: refers specifically
Legumes, plants of the family Fabaceae, for
to sorting and classifying
instance, have nodules on their roots which living organisms.
contain nitrogen-fixing bacteria. It therefore makes Precipitation: any liquid or
good sense agriculturally to alternate them with frozen water that forms in the
cereals (family Poaceae) and other plants that atmosphere and falls back to
require nitrates. A common modern crop rotation is the earth.
alternating soybeans and maize (corn). In Cultivation: The raising of
subsistence farming, it also makes good nutritional crops.
sense to grow beans and grain at the same time in different fields.

Crop rotation is also used to control pests and diseases that can become established
in the soil over time. Plants within the same taxonomic family tend to have similar
pests and pathogens. By regularly changing the planting location, the pest cycles
can be broken or limited. For example, root-knot nematode is a serious problem for
some plants in warm climates and sandy soils, where it slowly builds up to high
levels in the soil, and can severely damage plant productivity by cutting off circulation
from the plant roots. Growing a crop that is not a host for root-knot nematode for one
season greatly reduces the level of the nematode in the soil, thus making it possible
to grow a susceptible crop the following season without needing soil fumigation.

It is also difficult to control weeds similar to the crop which may contaminate the final
produce. For instance, ergot in weed grasses is difficult to separate from harvested
grain. A different crop allows the weeds to be eliminated, breaking the ergot cycle.
This principle is of particular use in organic farming, where pest control may be
achieved without synthetic pesticides.

A general effect of crop rotation is that there is a geographic mixing of crops, which
can slow the spread of pests and diseases during the growing season. The different
crops can also reduce the effects of adverse weather for the individual farmer and,
by requiring planting and harvest at different times, allow more land to be farmed
with the same amount of machinery and labour.

The choice and sequence of rotation crops depends on the nature of the soil, the
climate, and precipitation which together determine the type of plants that may be
cultivated. Other important aspects of farming such as crop marketing and economic
variables must also be considered when choosing a crop rotation.
 3.Mixed:
Mixed farming is a type of farming which involves both the growing of crops and the
raising of livestock. Such agriculture occurs across Asia and in countries such as
India, Malaysia, Indonesia, Afghanistan, South Africa, China, Central Europe,
Canada, and Russia. Though at first it mainly served domestic consumption,
countries such as the United States and Japan now use it for commercial purposes.

The cultivation of crops alongside the rearing of animals for meat or eggs or milk
defines mixed farming. For example, a mixed farm may grow cereal crops, such as
wheat or rye, and also keep cattle, sheep, pigs or poultry. Often the dung from the
cattle serves to fertilize the crops. Also, some of the crops might be used as fodder
for the livestock. Before horses were commonly used for haulage, many young male
cattle on such farms were often not butchered as surplus for meat but castrated and
used as bullocks to haul the cart and the plough.

4.Forestry:
forestry, the management of forested land, together with associated waters and
wasteland, primarily for harvesting timber. To a large degree, modern forestry
has evolved in parallel with natural resource management. As a consequence,
professional foresters have increasingly become involved in activities related to
the conservation of soil, water, and wildlife resources and to recreation.

5.Aquaculture:
Aquaculture, also known as aquafarming, is the controlled cultivation of aquatic
organisms such as fish, crustaceans, molluscs, algae and other organisms of
value such as aquatic plants.
Activity 1:
1. In your own words, explain what agriculture is.
2. What does agriculture provide as the real needs of people?
3. What raw materials does agriculture provide?
4. How does agriculture create 50% of the total populations’ jobs in South Africa?
5. Write a 50-word essay explaining the way in which you personally benefit from
agriculture.

Activity 2:
1. What is mixed farming?
2. What are the benefits of mixed farming?
3. What is Forestry primarily used for?
4. What is aquaculture?
5. Why is aquaculture production highly efficient?
 Agricultural Systems
Topic 2