Agriculture

What four components make up soil?

What four components make up soil?

Organic matter

Inorganic matter

Water

Air

Describe the characteristics of sandy soils

-gritty in texture

-water drains through it easily

-sand dries up quickly

Describe the characteristics of clay

-it drains slowly

-sticky when wet and hard when dry

Describe the characteristics of silt

-fairly well drained

-tends to hold more moisture that sandy soils

What is the use of nitrate ions in plant growth

they combine with glucose to form amino acids which in turn bond together to create proteins needed for plant growth.

What is the use of phosphates in plant growth

They are an important component of DNA and cell membranes and is required for respiration and growth

What is the use of potassium in plant growth

It must be present for the enzymes required for photosynthesis and respiration to function effectively

What is the use of magnesium in plant growth

It is used for manufacturing chlorophyll without it photosynthesis would not occur

What is the use of organic matter in soil fertility

-it increases the water holding capacity

-it increases the air spaces within the soil

-it prevents the loss of mineral nutrients

-it increases the number of decomposers thus providing additional drainage

Describe the differences between clay and sand

-sand has large air spaces while clay has poor air spaces

-sand drains well while clay has poor drainage

-sand has poor retention of humus while clay retains humus (aka moisture)

-sand is easier to cultivate while clay is harder to cultivate

Name the different types of agriculture

Subsistence farming

Commercial farming

Arable

Pastoral

Describe Subsistence farming

It is the cultivation of food to meet the needs of the farmers and their families

Describe commercial farming

It is the cultivation of food with the main aim of selling it for cash

Describe arable farming

It is the production of plants for consumption by humans

Describe pastoral farming

It is the rearing of animals and production of animal related products

Name ways you can increase agricultural yields

-Crop rotation

-Fertilizers

-Irrigation

-Mechanisation

-Selective breeding

-Genetically Modified Organisms(GMOs)

-Controlled environments

-Pesticides

What are the advantages of crop rotation?

-diseases in the soil affecting the plant are left behind

-the soil in the new plot is likely to have essential nutrients needed for the growth of another crop

-pest population is reduced as they need to find a new site

Describe the advantages and disadvantages of overhead sprinklers

Advantages

-it is easy to set up

-can cover a large area with one sprinkler

Disadvantages

-large droplets may cap the soil

-small droplets my be blown away by wind

-water lands on leaves and soil and may evaporate easily

What are the advantages and disadvantages of clay pot irrigation

Advantages

-simple technology is used

-easy to check the amount of water used

Disadvantages

-only suitable for permanent plants

-large labor cost

What is the use of water in plants?

-it is essential for cell activity

-it is used in photosynthesis

-mineral uptake requires water in the soil

What are the advantages and disadvantages of trickle drip irrigation?

Advantages

-water is placed directly at the base of the plant

-it is automated and controlled via computer

-water is used very efficiently

Disadvantages

-expensive to install and complex to maintain

-grit can block tubes

What are the advantages and disadvantages of flood irrigation?

Advantages

-inexpensive

-can cover large areas quickly

Disadvantages

-inefficient use of water

-damages soil structure

What are the benefits of mechanisation?

-larger area can be cultivated

-reduces labor costs

-ploughing can be done even when the soil is heavy

Why should pests be controlled?

-they compete with crops for light, water and nutrients

-they reduce the quality of a seed or grain crop

-they might be poisonous

-they make cultivation difficult

What are the advantages and disadvantages of biological control in dealing with pest problems?

Advantages

-no chemical residue

-no need to reapply

-the predator will die naturally when the pests are controlled

Disadvantages

-not as instant as chemical control

-pests may breed faster than the predator

-predator my feed on unintended plant